I’ve been asked dozens of times why I chose IMF for Prodigal, and not Loring or Probat. To understand that, I’d like to explain how those machines differ and why I believe IMF makes the best roasting machines in the world.
Drum roasters vs air roasters
Although IMF and Loring machines have drums, most of us call them “air roasters” because they transfer heat almost exclusively by convection with little-to-no conduction. Some air roasters, such as Sivetzand Neuhaus Neotec move the beans via a “fluidized bed” of hot air; other air roasters such as IMF and Loring use a drum to direct the bean movement, independent of airflow.
Over the years, marketers have done a good job of muddying the facts about drum vs air roasting. Air roasting advocates have often claimed all drum roasts are “burnt” and only air roasting is “clean” and some drum roaster fans have claimed air roasts have “no body” or “uneven development.”
While such claims may have some merit when a machine is used improperly, I do not think they accurately represent the results a semi-skilled operator would achieve.
A skilled roaster will find drum roasts offer a little more body, a bit less flavor clarity or delicacy, and less inner-bean development at a given outer-bean roast color. All of those differences are due to drum roasters transferring more heat via conduction.
Air roasters, on average, make inner-bean development easier and are less likely to impart roasty flavors. The same trade-off that exists between flavor clarity and body exists in roasting; increasing one decreases the other.
Air roasters allow faster roasting than drum roasters do, since air roasters can operate at extremely high inlet-air temperatures without concern of overheating the drum surface. The common notion that roasts should take “10-12 minutes” or the like is an artifact of most roasters using drums; let’s say you put a massive burner in a 12kg Probat and roasted 12kg in six minutes; the drum would get so hot that it would sear the beans, causing tipping, scorching, and likely inadequate inner-bean development at lighter roast levels. But it’s common to roast in 6-7 minutes in air roasters; hot air does not damage beans (for reference, in my ROEST, I use an inlet temperature as high as 700 fahrenheit during my 200-g batches with no cosmetic or flavor damage.
One could argue that roast consistency is a little easier with an air roaster, though I think nearly equal consistency is achievable in most machines, provided they don’t have features or control systems that interfere with an effective between-batch protocol.
Which type of roaster is better?
I don’t believe there is a one-size-fits-all roaster design. If you prefer darker roasts and maximum body, you should probably use a drum roaster. At darker roast levels, inner-bean development won’t be much of a concern, and you probably won’t mind the lack of flavor delicacy. If you prefer light roasts and high flavor clarity, you’ll probably want to choose an air roaster.
But, dear reader, please do not misinterpret what I’ve written here: nowhere have I said that you cannot develop light roasts well in a drum roaster or impart roasty flavors in an air roaster. These are merely comparisons of their relative performance.
IMF vs Loring
Given that I prefer light roasts and delicate flavors, I was definitely going to buy an air roaster for Prodigal. The choice came down to IMF and Loring.
Both machines use air-recirculation: instead of having a burner for the roasting process and an afterburner to clean the exhaust air, they have one burner held at afterburner-level temperatures to clean the exhaust air and provide hot air for roasting. Both designs are more fuel efficient than using a drum roaster with an afterburner. But the similarities end there.
Airflow: There are effectively two different airflows in IMFs and Lorings, what I’ll call “air throughput” and “recirculated air.” Think of them like this: imagine you are filling a leaky bucket with water from a faucet. The water entering the bucket and draining from the bucket are the “throughput.” If you simultaneously stir the water, that is the recirculation. The “types” of airflow in the IMF and Loring intermingle but their levels are independent.
Both machines recirculate air through their burners, and assuming one maintains the burner temperature high enough, the air is “cleaned” of smoke and pollution, to prevent the recirculation from tainting coffee flavor.
The amount of throughput in Lorings is correlated with the gas setting, in order for its fuel injection system to maintain a constant air:fuel ratio. So, when using a gas setting of 80%, the throughput is roughly twice as high as when the gas is at 40% (I’m not sure if it’s exactly a 1:1 ratio, but it’s close). I do not like this system for two reasons: it prevents the Loring from lending itself to inlet-temperature profiling (see below), and it means the air throughput is very low when using low gas settings late in roasts. This, to me, is the reason why the IMF is better at both controlling roasts through first crack and executing dark roasts.
The IMF exhaust fan and burner temperature are independently controlled. That means we can have whatever throughput level we want at anytime. It also allows one to use inlet-temperature profiling, which is the best way to control an air roaster.
Incoming air in the IMF is a combination of hot air from the burner and air from the roasting room, blended dynamically by a fluttering “vortex” valve that produces the desired inlet temperature at all times. The level of air throughput is determined by the exhaust fan setting, which is set by the operator.
To me, the only benefit of Loring’s lower overall air throughput is it makes the fuel efficiency higher than that of the IMF. The IMF’s higher air throughput offers superior control of roast curves at all times, especially when most needed late in a roast.
Airflow: advantage IMF
Fuel Efficiency: advantage Loring
Drum: The Loring’s drum is solid steel, while the IMF’s is perforated. While I don’t think that’s a big deal, I would always choose a perforated drum in order to decrease potential conductive heat transfer.
Drum: advantage IMF
Productivity: Both machines can roast full batches faster than a drum roaster. Some Loring machines seem more powerful relative to stated capacity than others (The 15kg seems especially underpowered.) But IMFs are more powerful than Lorings at any size, and one can roast full batches in less than 8:00 in IMF with no compromise in quality.
Productivity: advantage IMF
Control System: Loring offers three ways to control roasts: manually changing gas settings, using automated burner recipes, and “profile roasting.” Burner recipes are like manual control, but with valve settings preset by the operator, and executed by the machine (Cropster Gas & Replay, and Artisan software offer this same option for any machine that has a digital gas valve capable of receiving commands from the software.) In profile roasting, which I wrote about here, the Loring uses a PID to change the gas setting automatically, in an attempt to trace the bean-temperature curve of a reference roast. The system does not perfectly trace curves, because profile roasting gets confused during the first minute of a roast while the BT reading drops. After the turn, the system does a relatively good job of tracing curves, assuming the operator has programmed a curve achievable by the automation. I find the profiling system useful for very dark roasts, but a skilled operator can usually roast more consistently in manual mode than in profiling mode.
The IMF control screen allows the operator to create a twelve-step recipe using bean-temperature set points. The operator can choose the inlet temperature, drum speed, and fan setting at each bean-temperature set point. I cannot overstate the superiority of controlling roasts by inlet temperature rather than valve settings. For example, let’s say you have a Probat and have a recipe that looks like this:
gas 80@ BT300°F
gas 70@ BT320°F
gas 60@ BT340°F
The beans do not experience the gas-valve settings, they experience the inlet temperatures produced by those settings. However, since ambient air is drawn through the burner, unless the ambient temperature is tightly controlled, a given valve setting will produce different inlet air temperatures as ambient conditions change. For example, it’s typical for a certain gas setting to produce hotter inlet temperatures at the end of a roast session than at the beginning, if the roastery gets progressively warmer throughout a session. Likewise, inlet temperatures tend to be higher in summer than winter for a given valve setting.
Directly controlling the inlet temperature prevents inconsistencies due to changes in ambient conditions. I doubt many roasters until now have recognized the benefit of such a system. The improvement in predictability and consistency yielded by an inlet-temperature control system is why I asked ROEST to add that feature to its machines, and why machines like ROEST and IMF make roast replication much easier than machines that require control by gas-valve settings.
One cannot operate a Loring by inlet temperatures, and even if they could, the constantly changing air throughput of the Loring would make the heat transfer more challenging to manage.
Advantage: IMF, by a landslide
In this photo of the IMF recipe screen, the machine will deliver inlet temperatures of
485c @ BT174c
480c @ BT185c
475c @ BT191, etc
Please note these settings are not recommendations; they are merely examples.
Price
While price was never a consideration when deciding which machine to purchase for Prodigal, IMFs are, across the board, cheaper than Lorings. I doubt that will be the case for long, once roasters come to understand the benefits of IMF.
Advantage: IMF
Conclusion
While I consider Loring and IMF to be two of the best roasting machines on the market, I chose IMF for all of the reasons above. I confess that I didn’t start Prodigal earlier because I was frustrated with the choices of sample roasters and production roasters until recently. Now that I have found IMF, and ROEST has added inlet-temperature profiling, I couldn’t be happier with o results.
Since starting Prodigal, I’ve been thinking a lot about sample roasting. Sample roasting is arguably more important to final product quality than production roasting is, so I have been remiss in not discussing sample roasting more in the past.
What is sample roasting?
Sample roasting involves roasting small quantities of coffee, usually as little as 50g up to 200g, but most commonly 100g, to test and choose which lots of green coffee to buy. Sample roasting is also sometimes used to “profile” a coffee before production roasting, but the utility of such “profiling” is dubious. The word profiling can mean various things, but here it refers to the practice of attempting to learn how to roast a new coffee on a small machine, with the intention of transferring that knowledge to a larger machine. Unfortunately, it is difficult to transfer more than general insights (how much relative power does a coffee require to roast, approximately how does it behave around first crack, what roast color tastes good, etc.) from a small machine to a larger one. Profiling in this way can give one a “ballpark idea” of how to approach a coffee, but cannot, with our current technology and understanding, tell one precisely how to roast a coffee in a larger machine.
Types of sample roasters
Historically, most sample roasters were small drum roasters with open-faced drums, such as in the photo above. While such dinosaurs often churn out surprisingly delicious coffee, they make consistent, predictable results nearly impossible. For a deep dive into why these machines offer poor consistency, and how to modify them for better results, please see my post HERE
In recent years, a plethora of +/-500g drum roasters have hit the market that offer more controlled and consistent, if not always as delicious, sample roasts. Most such machines come from China, have similar features, and none stand out as particularly special. The positive aspects of these machines include fully modulating control over gas, drum RPM, and airflow, and easy connection to software such as Cropster or Artisan. However, some of these machines roast with too much conduction, most have slow bean probes in frankly stupid locations, and some have the reliability of an Edsel. If you don’t know what an Edsel is, consider yourself fortunate.
If you are going to buy one of these small drum roasters, I recommend getting one of the cheaper ones, because they are all similar, with nearly identical designs, and usually require the user to replace and move the BT probe, possibly the gas-pressure gauge, and often a few other small features.
More recently, air roasters such as the Ikawa, Kaffelogic, and Roest have hit the market. The potential roast quality out of air roasters is generally superior to that of drum roasters, since air roasters transfer little to no heat by conduction, but instead use convection, which makes it easier to develop coffee and avoid roasty (not a real word) flavors. Until recently, I was frustrated by the control and repeatability offered by most of these machines, although all have the ability to produce delicious coffee at least some of the time.
What I use
Prior to 2022, my preferred sample roaster was a 500g drum roaster. Such machines offer good data quality down to 100g batches, and offer probably the most insight into how a coffee may behave in a production roaster. Roast quality was “pretty good” but consistent and predictable. I’d rather roast at a quality level of 8/10 consistently than have erratic, and occasionally better, sample roasts, because one needs consistency to give each green sample a fair trial.
More recently, at Prodigal I began using the Roest. For full disclosure, I did not pay for the machine. You don’t have to trust me, but no amount of free stuff could make me use anything but the best possible machine at Prodigal, or could compel me to write a blog post about a product. I needed a great machine to get the most out of my coffee, and for years I’ve been begging manufacturers to build exactly what Roest has built.
My relationship with Roest was rocky at first, as I had a disagreement with someone at the company about roasting data. Because we had such different perspectives, I invited some of the Roest folks as guests at my roasting seminar in Boston last year. They took notes, asked questions, shared their experience designing machines with the class, and — wonderfully — embraced the importance of an effective warmup and between-batch protocol. They were excited, because they recognized an effective BBP was not only necessary for good consistency (yes, even in an air roaster), but also essential for successful automation and replication. I was excited, because a manufacturer finally engaged and cared about the importance of a quality warmup and BBP :). Further discussions led to the addition of an inlet-temperature probe, because using an inlet-temperature recipe is the most effective way to manage an air roaster consistently (more on that in a future post).
A roast using an inlet-temperature profile (please ignore the “yellowing” note)
Last year, Roest added the ability to create customized warmup and BBP profiles, and now the machine automatically triggers the BBP upon dropping a batch. I cannot say how happy that makes me as a roaster, and also the only person yelling about the importance of an effective BBP for years. The last piece of the puzzle happened this month, as Roest now offers the option to create inlet-temperature profiles based on bean-temperature set points instead of time. Such as system makes consistent, predictable, high-quality roasting possible in a way it had never been before.
I’m grateful to Roest for the machine, but more grateful they care about details, consistency, and continual improvements. Choosing a sample roaster is finally a no-brainer for me.
NB: Readers may notice some similarities between the Roest and the Decent espresso machine. I’m fond of both machines for similar reasons: each is a seamless marriage of user-friendly, clever software and hardware, both companies listen to feedback and rapidly improve and update their software and hardware, and they offer unparalleled control and real-time information while roasting and making espresso, respectively. Most importantly, each offers better coffee, more consistently, than any other machine in its category.
Roest screenshots: 1) An inlet-temperature profile 2)Profile log 3)Roast comparison
Portland Classes
Please join Samo Smrke and me for our masterclasses in Portland.
You can find tickets and details about my roasting masterclass HERE.
Tickets and details of Samo’s “Improving coffee with science” class can be found HERE
Prodigal Update
Prodigal is on hold for another month or two, while we finalize our permits and the installation of our IMFroaster. We may release a small amount of extremely delicious coffee in the next couple of weeks, as we have some stunning green that we want to roast while it is still incredibly fresh. We will update our mailing listandInstagramfollowersas soon as we know when we will get back to a regular roasting schedule.
Prodigal Coffee at SCA Expo
I’m pleased to announce you will be able to taste two smashing Prodigal coffees at SCA Expo, our washed Colombian “Finca La Indonesia” sidra and washed Colombian “Francy Castillo” geisha. I will roast both coffees on the ROEST, the machine I consider hands-down the best sample roaster.
You can taste Prodigal’s coffee brewed in the new NextLevel Pulsar by the fine folks of NextLevel (they will share Sivetz Roasters’ booth) and also at the ROEST booth. I will spend time brewing the coffees at the two booths, and I’ll post my schedule on Instagram on the day of the event so you know where to find me.
My intention is to not only showcase what the ROEST and Pulsar can do, but to make sure these are the two most memorable coffees you taste at Expo!
You can, of course, also taste Prodigal coffees at my Roasting Masterclass on Saturday.
Thanks to Apex Coffee Imports for sourcing two of the cleanest, prettiest, most floral coffees I have tasted in recent memory.
I look forward to seeing you in Portland!
HOW TO BE A BETTER CUPPER
Mar 09, 2023
Ahead of the launch of Prodigal, Mark and I cupped for a minimum of one hour each morning. Having such a routine allowed us to calibrate well after cupping more than 2000 samples together. Those sessions also taught us a lot, some of which I’d like to share here. First, I want to credit Ryan Brown. Over the years, I learned a lot not just from cupping with Ryan, but from throwaway remarks he would make. To him, many of those remarks were the equivalent of cupping small talk. To me, they often held pearls of hard-earned wisdom. Ryan is rigorous in creating systems that prevent bias and help to confirm his findings about samples. A good green buyer cups each sample multiple times on multiple days and does everything possible to avoid bias. Until launching Prodigal, most of my cupping was done through the eyes of a production roaster and cupping was mostly an exercise to evaluate roast quality. I focused on problems of baking, roast development, side effects of excessive conduction, and the like. I did not cup to intensely analyze the merits of one green lot vs another. But production-roast cupping improved my green-evaluation skills.
Herein are what I consider some cupping best practices.
Always cup blindly
This rule may seem obvious, but in my experience, few roasters follow this rule religiously. I get it: cupping blindly with others can be embarrassing and humbling. But cupping isn’t a competition. You can either protect yourself from looking bad, or you can learn from experience, but you can’t do both well at the same time. Suck it up, make mistakes, and don’t worry if you thought that wet-hulled Sumatra was a washed Kenya. It happens to everyone.
As often as possible, consder “double blinding” a cupping by having someone else set up the cupping so the cuppers do not know what coffees are on the table.
To make cupping as blind as possible, consider hiding visual differences in coffees; for example, if you have a variety of roast levels on the table, it helps to cup in bowls with black interiors, in order to not see the colors of the brews. Some training sessions even use sunglasses to decrease visual cues about samples.
Please do not use the traditional practice of setting a sample tray of roasted coffee next to each cupping bowl. That makes it impossible to be appropriately blind when looking at the roasted beans of a sample.
Always cup with others
Cupping with others is far more educational than cupping alone. Various people will perceive different flavors in coffees, and some people are better at perceiving certain defects than others are. Cupping with others is a great way to expand your tasting abilities. For example, Mark is better than I am at tasting certain underdeveloped flavors, while I am more likely than he is to detect fade in coffee samples. Cupping together helps us shore up our weaknesses.
Try to cup with more experienced professionals whenever possible.
This is a no-brainer. Cupping with more experienced pros is by far the best accelerant if you want to get better at tasting coffee.
Always take notes during cupping
Please don’t try to memorize your impressions of 5–10 cupping bowls; it is always better to take notes to discuss results with others, for scoring coffees accurately, and for future reference. I don’t believe one needs an official score sheet to score samples accurately, but I do believe it takes months of calibration practice to score accurately and consistently.
Wait until after everyone has done at least one round of slurping and note taking before discussing samples
I’ve been to many cuppings where people begin discussing the coffees as soon as they begin tasting. That is more fun than taking notes silently, but it also inhibits learning and increases the risk of bias.
Be as rigorous as possible in cupping procedure
What I mean by this is: use a consistent grind setting (I usually grind at a setting 1-2 integers finer than a typical 20g pourover setting) and water chemistry, weigh grounds to 0.1g resolution, weigh water to within a few grams per bowl, grind, pour, and taste on a timer with a rigorous schedule, and consider cupping at a brisk but comfortable pace to ensure you are tasting all samples at similar temperatures. Ryan taught me to take just one or two slurps per sample and to focus hard on those slurps. That has helped me cup more quickly. Previously I was taking too many slurps per bowl, which was taking too much time, decreased my focus , and caused my palate to fatigue earlier.
Take one or two slurps, jot down a couple of words in your notes, and move to the next bowl. It’s okay if you don’t perceive an encyclopedia of descriptors after just one or two slurps.
When cupping to choose green, do your best to optimize cup quality
When cupping to decide what green lots to purchase, sample roasting and cupping should be done in a way that optimizes cup quality. That will allow each green lot the shine and show its best features.
When cupping for production roasting QC, consider sacrificing cup quality, if necessary, in order to detect roast defects more easily
Let me explain this idea… Personally, I use an identical procedure when cupping for green buying and cupping for production roast analysis. However, I’ve cupped with many companies whose coffees tasted better when using a coarser grind or lower water temperature during cupping. In those situations, grinding finer or brewing hotter likely highlighted roast defects. If your cuppings taste better at grind settings coarser than your typical pourover grind setting, then there is probably work to do to improve roast quality. But please do not change the grind setting or water temperature to improve the flavor of cupping bowls.
Always cup at least one sample from another roaster on every table for context
I find many roasters are biased in favor of their own coffees. I recommend roasters find the best coffees they can from competing roasters, and to always have at least one such sample on every cupping table for context.
Test the effectiveness of your cupping system
Many roasters have told me something like “This coffee cupped sharp on day one out of the roaster, was super fruity on day two, the flavors were muted for a few days and then the coffee was cupped great again after one week.” While I don’t doubt that cupper’s experience, it is unlikely the coffee really got worse, better, worse, and better. It’s possible, of course, but it’s more likely the cupping system is to blame, or the coffee has an abundance of quakers or other dodgy beans that show up in some samples but not others.
To test the reliability of your cupping system, try something like this:
Scatter three bowls of the same coffee among several other coffees on the cupping table. Note whether your tasting notes and scores were consistent for those three bowls.
Taste several bowls of the same coffee several days in a row, again scattered among other samples, to see whether your notes change day to day.
With a little effort, you can taste the baseline reliability of your cupping system. If the three bowls in each of the trials above tasted and scored identically, your system is probably reliable. If the three bowls varied a lot in flavor
, it’s important to run the same test with a few other coffees to see whether the cupping system or the coffees themselves are inconsistent.
In general, scattering multiple bowls of a particular sample throughout a cupping table and trying to identify them is an excellent exercise to hone your tasting ability.
Re-cup your roasts several times over the few weeks after roasting
Once you have shored up the reliability of your cupping system, it is worth tasting various roast batches over several weeks after roasting to perceive how the coffee ages and evolves. You may find your coffees typically peak after a certain number of “resting” days or you may find your coffees peak within a day of roasting and decline from there.
Regularly testing and monitoring the quality of your roasts as they age can help you optimize your customers’ experience.
Cup more rigorously when purchasing green than when analyzing sample roasts
When cupping to select green for purchase, I consider it essential to cup multiple bowls of a candidate sample multiple times before choosing a green lot. Not only do I want several looks at a coffee in order to avoid defects that may appear in only some bowls, but I want to confirm my impression of a coffee before committing to it.
When cupping production roasts, we are usually confirming the consistency of our results, or testing whether one approach works marginally better than another approach to roasting a particular coffee. Occasionally I will re-cup a roast batch to get a clearer picture of its quality, but usually one bowl is sufficient per batch.
photo credit: @coffeeandlucas
Prodigal Update: month two and a discussion of roast quality vs roast style
Feb 03, 2023
Lessons from the first month
We received multiples more inquiries than we had coffee available. Some of that was due to us deciding some of our green, once arrived, was below our quality standards for Prodigal, and some was due to my poor forecasting skills.
Roasting and filling orders and handling inquiries was quite a challenge, as we had expected a much slower start. To be frank, no part of the process ran as smoothly as I would have liked, but we intend to be far more prepared for our next roasting and fulfillment session.
Before the launch we did not have a green moisture meter, color meter, or enough staff to double-check every order. We also didn’t have experience with how our roasts would evolve due to travel and resting. All of that is sorted now.
The first day of roasts (Jan 4) cupped beautifully directly out of the roaster and the next morning. A week or two later, the coffees tasted “too developed” but not roasty. I issued a public apology and offered to make any dissatisfied customers whole. Three customers took us up on that offer.
Working on a new machine in an environment I couldn’t control was challenging. Contrary to popular belief, roasting is about systems and controlling variables, not about sniffing beans in a trier or some sixth sense about what is happening to 50,000 beans inside a giant hunk of hot metal. Having sixty batches under our belts, learning when to roast (at night, in a sealed, climate-controlled space), and how our coffee would age with time, will all contribute to future improvements.
The vast majority of feedback was wildly positive; we received many comments such as “the best coffee I’ve tasted in over six months,” “the juiciest roast I can remember,” etc. The majority of critical comments were something like “it was not roasty but it was more developed than I prefer.” As noted, those batches have been acknowledged, and I don’t expect many of those roasts or comments in the future, other than from the more extreme tasters out there. Doing the best one can is not the same as pleasing everyone.
A couple of weeks ago we upgraded our sample roaster and began using the Roest. After a few days of a steep learning curve on the Roest, we’ve settled into a system using the new inlet-temperature recipe program and automated BBP. We’ve been pleased with the overall results. I’ll write a post soon about our experience with the Roest.
We sold coffee wholesale to three cafes with whom we had prearranged deals. With apologies to others who made wholesale inquiries, we did not have enough green to sell wholesale to any other cafes. We hope to change that soon, but it will depend on retail demand and green availability. Likewise, we hope to offer a subscription soon, but cannot do so until we are confident about having a steady stream of green that meets our quality threshold.
Roast level vs quality of roast
Having consulted for well over a thousand roasters over the years, I have to remain relatively adaptable about roast level. It is not my job to tell my clients how light or dark to roast, it is to help them achieve their desired roast level in the highest-quality and most consistent way possible. I’ve literally never told a client “you have to roast darker (or lighter)” or “you have to roast to 20%DTR,” etc. What one writes in a book for mass consumption is necessarily different from what one prescribes to a roaster with a particular machine and unique goals. As a consultant, step one is to ask a client his or her goals. Step two is to help them achieve those goals. Everything must be customized for that client.
Like any coffee drinker, I have my personal preferences. I prefer light, juicy roasts of clean —usually washed — coffee, and famously despise funk. I respect that others have different preferences.
There is, however, a difference between roast level and quality of roast.
I’ve noticed many people confuse the two. A roaster may roast darker than I like, but do a great job of optimizing that roast level. Likewise, another roaster may roast in the color range I prefer, but the coffee may be baked or underdeveloped. I do not judge roasts solely by the final color, I also judge them by how skillfully the roaster achieved that roast level.
Roast level is a style choice. Roast quality is independent of roast level. I don’t see that distinction made often enough.
What’s next
Prodigal will release four new coffees this week. I’m pleased to say the new release will include our first natural :0, our first blend (the components of which will remain a mystery until next week’s blog post), a new shipment of the lovely Betel Geisha, and our first coffee from Ecuador.
We always notify our Prodigal Mailing Listsubscribers a day before anyone else of our new releases. If you don’t want to miss out on the new offerings, please consider joining the mailing list.
Thanks for your support
Prodigal week one: lessons and confessions
Jan 09, 2023
“Transparency,” like “sustainability,” is a word thrown around too often. Let’s face it, very little in modern society is truly sustainable. Likewise, transparency in business is always selective and limited.
It is nice to know that a roaster paid $10/kg FOB or $5/KG at the “farm gate” but do we know what that really means to the producer? It’s always more complicated than it seems. We paid $19/lb ($41.80/kg) before shipping for our two Betel coffees, but we don’t know César’s input costs or the cost of living in his part of Colombia. I don’t know how he and his family are doing financially, but he produces lovely coffee and he seems happy.
It’s easy to say “this is what we paid” but it’s difficult to know what the numbers mean. One USD of income is a very different thing in Cauca and Copenhagen. I can imagine economists arguing endlessly about how to compare the value of a dollar in each place.
Financial transparency is nice, but tricky to make sense of at times.
At Prodigal, we hope to practice a different type of transparency more relevant to our customers: owning up to our virtues and mistakes. I’ve ordered coffee from hundreds of respected roasters over the years, and as every honest, experienced coffee professional knows, inconsistency is rampant in our industry.
Sources of inconsistency in coffee
Green coffee quality can change radically from the cupping table at a mill, to a PSS (pre-ship sample) from an importer, to an arrival or spot sample offered in the country of the roaster. A small change in green temperature or ambient roastery temperature can be the difference between a deliciously developed and underdeveloped roast. Heck, even what was roasted the previous batch can dramatically impact the current batch, unless one has an appropriately slow, systematic BBP (between-batch protocol), and even then, there are times when a BBP has a difficult time compensating for extreme changes in batch-to-batch roast styles (eg switching from a dark roast to a light roast or changing batch sizes mid-session can cause a roaster fits.) Throw in problems with water chemistry, brewing technique, and grind quality, and it’s a wonder that we ever enjoy two consecutive cups of coffee.
Prodigal: consistency, standards, and flops
When Mark and I launched Prodigal, we fretted over every detail that could affect quality, and we still came up short in some ways. For example, we cupped over 100 green samples, begged suppliers to be very selective in what they sent us, and we purchased only seven coffees.
All of the coffees we purchased cupped at 87.5+ as PSS. We score strictly, and if you see any green sellers or roasters claiming they are awash with 88+ coffees, please disregard them. Score inflation is real. We calibrate with COE judges and impartial Q Graders, not marketing scores.
Upon arrival, a few coffees held up and matched their PSS quality, and a few declined by 0.25-0.75 points across numerous sample roasts. We made the difficult decision to not sell those coffees as “Prodigal” because we want to uphold a certain standard for our brand, even if it means we sell less coffee. All of the rejected coffees are still lovely, and i reckon almost any coffee pro would happily drink them.
We are selling our good-but-rejected arrivals as green coffee to home roasters, as they are tasty, and a bargain relative to what home roasters can source through the usual channels.
Green buying is the most important and difficult job of a roasting company. Green coffee is alive and constantly changing. Precious, delicious green gets exposed to a variety of conditions between the mill and the roastery that can and will degrade quality. We missed by a little on three of our seven purchases. We will find transparent ways to unload our green that doesn’t make the cut.
Roasting
I separate third-wave roasters into three groups; note that companies I refer to here may offer more than one roast level or style. I am focusing on their “filter” roast offerings, and don’t mean to imply that they target only one goal or style for all of their offerings. They are merely illustrative examples using high-quality, familiar roasting companies. I have enjoyed coffee from all of these companies and roast styles at times.
“Nordic” style roasters favor cup clarity above all else. Examples of such roasters include Sey, La Cabra, and Tim Wendelboe (Tim crosses over into the “maximum juiciness” group frequently, in my opinion.) Fans of those companies are virtually allergic to “roast” flavors and most fans would probably choose to sacrifice some sweetness, body, and juiciness to achieve maximum clarity. One may often need to “rest” Nordic roasts for several weeks or months to decrease the perception of underdeveloped flavors.
“Maximum juiciness” roasters target a balance of acidity and sweetness, and are willing to sacrifice a bit of body or clarity to achieve their aims. Such companies include Regalia, Nomad, and Doubleshot.
“Fully developed” third-wave roasters focus on sweetness and juiciness, and sacrifice a some acidity and clarity to meet their goals. Examples of such roasters include Onyx, Go Get ‘Em Tiger, and Blue Bottle.
Each group has its fans and detractors. Some Nordic-style fans tend to call everything else “dark,” which is like a guy who is 6’5” calling everyone else short.
The common complaints about Nordic roasts, beyond their light, tea-like body, include flavors reminiscent of peanuts, vegetable broth, grass, and cellulose. Most Nordic roasters drift into that flavor territory periodically. To me, it is a fail; to others, it’s no big deal.
“Maximum juiciness” roasts may be too low in clarity or acidity or body, depending on the coffee drinker.
“Fully developed” roasters may stray into “roasty” territory on occasion, or suppress acidity enough to make some coffees taste a little dull.
For the record, my personal preference is on the light end of maximum juiciness. But it is not always wise to attempt to target one’s ideal roast level, as discussed below.
Prodigal beans, left to right: Betel geisha, Fidencio Castillo (caturra and Colombia varieties), and La Argentina pink bourbon
Prodigal’s roast style
We are currently roasting on a friend’s Probat. While we roast on that machine, we will target “maximum juiciness.” Once we have installed our IMF roasting machines, we are likely to lighten our roast level by a few degrees Fahrenheit, or approximately 5-10 points on the Agtron Gourmet Scale.
Why would we roast darker on a Probat than on an IMF? An IMF, like a Loring, is a convection-dominant machine that recirculates exhaust air through a burner held at 600 to 700°C. Such machines are very fuel efficient and make inner-bean development easier than do classic-drum roasters. When inner-bean-development is easier to achieve, it is safer to roast light with less risk of underdeveloped flavors.
My mistakes
When we launched Prodigal, we thought we had enough green to last a few weeks. Instead, we sold out in 24 hours. That presented several challenges to our efficiency and quality. We not only had to roast through the wee hours of the morning several days in a row, but we learned the hard way on our first roast day that our roastery’s ambient temperature was not stable enough to roast on our preferred knife’s edge of Nordic/maximum juiciness without flirting with underdeveloped flavors or losing some juiciness.
Three batches from day one went into bags of “first batch” beans we sell at a steep discount. The “first batch” offering was very popular, and we look forward to feedback from customers who purchased our “first batch” coffees.
To combat consistency and development problems, on day two we stabilized the roastery’s ambient temperature by roasting at night when no one would open doors to the frigid Colorado air. Along the way, we cupped every batch directly out of the roaster (!), as well as the next morning, and we were happy with the results. We see ways to improve, and we see every batch and cupping as an opportunity to learn and improve.
We will always cup every batch before packing it in Prodigal bags. It’s time consuming and makes our systems less efficient, but we think it’s worth it.
Unfortunately, those roasts from day one lost some vibrancy over the next few days, and I reckon by the time some international customers receive those beans, the roasts will be in the “fully developed” camp. We’re thrilled with their sweetness, and none of those batches tastes “roasty,” but we missed the sweet spot on several batches from day one. I’m frankly a little embarrassed by that. We will do everything in our power to ensure that never happens again. (Note: please do not “rest” our beans; drink them ASAP upon delivery.)
Thankfully, the next two roast days were more on-target and consistent, we were able to safely lighten our drop temperatures by 3°F/1.5°C, and we now have a tighter rein on green-storage temperature, roastery ambient temperature, and our approach to the Probat. Perhaps 25% of our roasts fell in the “fully developed” camp and the other 75% were in the “maximum juiciness” category. Nothing was baked, underdeveloped, roasty, or flicked, but some of our roasts taste darker than we would have liked. If you purchased some Prodigal coffee and found it too dark, please let us know.
Our promises to you
Coffee is challenging. We’re always learning, our standards and preferences are always evolving, and we are all fallible. I rarely hear roasters own up to their mistakes or inconsistencies, and often see them fight back against legitimate customer complaints. I’d like to do things differently.
If you are ever unhappy with any Prodigal purchase, please reach out to us directly (preferably without maligning us online first) and we will find a way to satisfy you.
No company or roast style will please everyone, and I expect to hear an equal amount of “you roast too light” and “you roast too dark” comments over the coming years. We’ll do our best to set clear expectations, communicate about our mistakes, and manage customer relationships with respect.
We will alert our mailing list first when we have new coffees!
HOLIDAY COFFEE GIFT GUIDE
Dec 06, 2022
Welcome to my semi-annual Holiday Coffee-Gift Guide. I thought it would be nice to suggest a few coffee-related gifts for the coffee nerd in your life. I won’t tell if you buy yourself the gifts or ask me to send this blog post to a family member ;).
These suggestions are completely biased: they are all products I enjoy, and some that I sell.
Forget overpriced, dumbed-down industry courses; the BH Unlimited Subscription is hands down the best all-around online coffee education money can buy. Coming from someone who offers coffee education for a living, I hope those words carry weight. Whether for you or for your café staff, BH is the best option. In 2023, BH Unlimited is going to get even better, as a certain blogger you follow will be contributing to the subscription’s roasting content. Click HERE to sign up and get a 14-day free trial.
If you *really* like someone, get him or her a Lagom grinder. The Lagom P64 and P100 are the best single-dosing grinders on the market, in my opinion. The grinders are beautiful, have low retention, excellent burrs, adjustable RPM (an important, underrated feature), and the are well-aligned at the factory (Thank you, Option-O, for caring.) In other words, Lagom offers everything you can ask for in a grinder.
Crafted by my friend Martina in Golden, CO, Spinware Ceramics are clean, beautiful, functional, and durable. Martina’s work would make a great gift for anyone who drinks coffee or tea.
From Spinware’s website: “When you buy a handcrafted piece from a ceramic studio, you are buying more than an object. You are buying hours of experimentation and error. You are buying moments of frustration and happiness. You are buying a piece of heart, a piece of soul, and a piece of someone else's life.”
was already the best-value home grinder on the market for making filter coffee (note: it is not designed to grind fine enough for espresso or aeropress) before they released their v2 burrs in late 2022. Now it’s the best-value home grinder with even better grind quality (but still not made for espresso.)
I don’t usually pre-sell my online classes, but in case someone would like to give or receive a class as a gift, I thought I’d make tickets to my upcoming March online roasting class available now. The class comes with daily access for one month to a private group in which I will answer any and every question asked, and help students manage their roast curves. This is the most factual and practical roasting class in the world.
The Clever Dripper doesn’t get the credit it deserves. Compared to a pourover, the Clever produces delicious, non-astringent coffee with less effort and skill required. Pro tip: add the water first to yield higher and more even extractions. When adding the water first, one avoids the two most challenging problems in pourover brewing: achieving even extractions and extracting at high-enough temperature to make acidity “pop.”
I’ve owned enough cafés to say with authority that this is a good book. While it’s tempting to dismiss the book as “mostly common sense advice,” it is packed with great advice aspiring and current café owners should follow, but few do. Colin’s writing is informal and pleasant, and the book is peppered with stories and lessons he learned while building his successful company 3fe in Ireland.
Doubleshot from Prague doesn’t get the attention it deserves, perhaps because they don’t roast super-light, but attempt to highlight the juiciness and ripe fruit notes in coffee by roasting light/medium. Regardless, Yara from Doubleshot is one of the world’s best green buyers, and his production-roast cupping tables are as delicious as any I’ve experienced. Doubleshot is offering a Christmas Coffee Set featuring two washed Colombian coffees from the Imbachi family, whom Yara has worked with for eleven years. Both coffees, caturra and pink bourbon, are grown on the same farm and processed identically. This set is a unique opportunity to taste the influence of coffee variety on flavor. Expect big, juicy, ripe fruit notes with a hint of spices (it is Christmas, after all.)
Click HERE to purchase in North America and HERE to purchase in Europe and the rest of the world.
Lotus Water Drops: While there are plenty of powder sachets you can buy to optimize your coffee water, I prefer the Lotus Water Drops, both because many of the sachets on the market produce inconsistent results, and because the LWD mineral concentrates are easier to use. To be honest, I’ve spent a few too many Saturday mornings exploring how different LWD recipes affect coffee flavor. If you need suggestions for how to use the drops, see my blog post here.
After 15 years of writing and consulting, I’ve missed producing something tangible, and decided to get back into roasting. My new company Prodigal, based in Boulder, Colorado, doesn’t intend to be large or take over the world. What we want is that thing we’ve never been able to find: a source of clean, juicy, delicious coffees, always roasted meticulously. Our promise to you is every coffee we ever ship in a Prodigal bag will be well developed, not baked, and not roasty (and not funky haha). If we make a mistake, it’s our problem, not yours. Count on it.
Our first offering is a set of four gorgeous, clean, washed Colombian coffees. Not only will our first month’s offering come separately or as a set of four coffees, but we will offer our customers an online, interactive cupping session with Shared Source founder Andrew Kelly, who imported the green, and myself. Prodigal customers are welcome to cup and score with us, and ask questions along the way. Prodigal will launch in the coming week. Please follow us on Instagram @getprodigalcoffee; we will offer our Instagram followers a discount on the first order and they will always be the first to know when we release a limited-edition coffee likely to sell out quickly.
LOTUS WATER DROPS: How to use them, and a great hack to find the best water for your coffee
Dec 02, 2022
Years ago, the main concerns about water for coffee were “don’t scale up your espresso machine,” “don’t make coffee with very hard water,” and “don’t use water that tastes or smells bad.” Times have changed; since the advent of the Barista Hustle water recipe and products like Lotus Water Drops, capable of independently manipulating water hardness and alkalinity, coffee enthusiasts have become much more interested in customizing water to enhance coffee flavor.
Over the past few months I’ve been using Lotus Water Drops at home to make coffee and to learn more about the effect of water chemistry on coffee flavor. In this post I’d like to tell you about the drops, the standard way to use them, and a shortcut I use to discover the optimal water for a particular coffee.
About the drops
A kit of LWD contains four dropper bottles:
Calcium Chloride (CaCl2)
Magnesium Chloride (MgCl2)
Sodium Bicarbonate (NaHCO3)
Potassium Bicarbonate (KHCO3)
The Calcium (Ca) and Magnesium (Mg) contribute to hardness
The Sodium (Na) and Potassium (K) Bicarbonate contribute to alkalinity
(All references to ppm in this post refer to ppm as CaCO3 equivalent.)
For 450 ml of water:
1 drop Ca adds 10 ppm hardness
1 drop Mg adds 10 ppm hardness
1 drop Na adds 5 ppm alkalinity
1 drop K adds 5 ppm alkalinity
For one gallon of water:
5 drops Ca adds 6 ppm hardness
5 drops Mg adds 6 ppm hardness
5 drops Na adds 3 ppm alkalinity
5 drops K adds 3 ppm alkalinity
Hardness and Alkalinity basics
Hardness, also known as General Hardness (GH), is a measure of divalent ions (ions with a positive charge of 2+). Magnesium and Calcium make up the bulk of hardness in water, and, depending on their levels and ratios – and who you ask :0 – may add “sweetness,” “structure,” or flatness to coffee.
Alkalinity, also known as Carbonate Hardness (KH), buffers acidity. Too little alkalinity, and coffee may taste acidic and unrefined. Too much, and coffee may taste chalky or flat.
Note that the flavor effects of these minerals are not “linear” or always predictable. For example, I recently tested four LWD recipes using the same coffee, and the cups at 10 KH (low) and 70 KH (moderately high) “popped” and tasted better than the cups at 30 KH and 50 KH. At extremes, such as 0 KH or 150 KH, the effect of KH on flavor is more predictable.
I prefer a little sodium in my coffee water because sodium counteracts bitterness. If you want to tame a bitter coffee such as a robusta or dark roast, adding extra sodium may help. If for some reason you must drink a dark-roast robusta, just dump an entire salt shaker in the mug after brewing.
Alkalinity for filter coffee and espresso
When adding minerals to water, one can do something not usually possible with standard water-treatment systems: easily and radically change hardness or alkalinity independently of the other. Very hard water is not great for coffee making because some of the hardness will precipitate as scale upon heating the water, and scale can damage coffee machines. However, very high-alkalinity water can have positive effects espresso.
Many coffee professionals agree that when making filter coffee, water alkalinity levels around 30–40 ppm yield reasonable levels of acidity. Given that alkalinity neutralizes acidity, and filter-coffee strength is approximately 1.2–1.4% TDS, to neutralize acidity in espresso at a strength of 10% TDS requires water with perhaps 7–8 times more alkalinity. With LWD or a jar of sodium bicarbonate, one can experiment with neutralizing espresso acidity for interesting effect. I doubt making espresso with KH of 200-300 ppm will become the norm, but I have found the results enjoyable and insightful.
Protecting your machines while experimenting
Calcium can create scale but Magnesium cannot. Therefore, you can test high-hardness and high-alkalinity recipes by increasing Magnesium and bicarbonate without increasing Calcium beyond a certain level. To estimate the scaling and corrosion potential of a recipe, you can use this online calculator.
How to use Lotus Water Drops - the standard method
The traditional way to use LWD is to add drops to distilled (demineralized) water. If distilled water is not an option for you, reverse-osmosis water is the next best option, but one can add LWD to any water to increase its hardness or alkalinity.
A couple of standard filter-coffee recipes based on distilled would look like this:
*the Rao/Perger recipe is the brainchild of Dan Eils, my partner and 3D printing expert at Litmus Coffee Labs
To one gallon of distilled or RO water, add:
25 drops Ca
50 drops Mg
30 drops Na
40 drops K
My Lotus Water Drops hack to reverse engineer your preferred water chemistry
Recently I was frustrated by the myriad possible water chemistries and decided to create a shortcut to finding what water chemistry would make the beans in my kitchen taste best. Using a surprising recent insight from chemist Samo Smrke that coffee tastes the same whether water minerals are added before or after brewing, I decided to brew a large amount of coffee using distilled water, split the brew into several equal portions, and add LWD to the brewed coffee.
Here is a shortcut to zero in on your preferred water chemistry:
Brew 900ml of coffee (you can do this by combining multiple pourovers, using one giant immersion, or whatever is convenient.)
Stir the brewed coffee well.
Pour equal 225ml portions into four cups.
Add a different combination of LWD to each cup. Each drop of Ca and Mg will add 20 ppm GH; each drop of Na and K will add 10 ppm KH)
Stir and taste (preferably blindly)
For example, I tried this recently to zero in on my preferred KH level for a coffee:
Cup one: 1 Ca + 2 Mg + 1 Na (60 GH, 10 KH)
Cup two: 1 Ca + 2 Mg + 2 Na + 1 K (60 GH, 30 KH)
Cup one: 1 Ca + 2 Mg + 3 Na + 2 K (60 GH, 50 KH)
Cup one: 1 Ca + 2 Mg + 4 Na + 3 K (60 GH, 70 KH)
Note that while KH drives acidity level, you may not sense a difference between levels as close as 10 KH and 30 KH. I recommend beginning with much larger differences, such as 10 KH, 50 KH, 100 KH, and 150 KH. Once the differences are apparent, you can challenge yourself with smaller variations in GH and KH.
Lotus Water Drops for roasters
Any roasting company that sells coffee outside of its home city faces a dilemma: how to roast coffee to suit the variety of water chemistries its clients use. There is no easy answer to this. One option would be, of course to use a common/recommended water chemistry (such as the Rao/Perger recipe above) and to encourage customers to use similar water. Another option would be to use LWD to mimic a variety of common water chemistries customers are likely to use, and to roast in a way that yields good results for that spectrum of chemistries. LWD is probably the most convenient way to mimic customers’ water chemistries.
ClickHERE to for more information and to purchase Lotus Water Drops
Score inflation, and my failed quest to find 88s
Sep 27, 2022
Last month I posted a request on Instagram for 88-point coffees, with the promise to promote any samples that I (and a Q-Grader friend) scored 88 in a blind cupping. The purpose of the offer was not to get lots of free coffee (that’s the last thing I need), but rather to understand more about how roasters score, and what they know about scoring. The experience was eye-opening in unexpected ways
The results
First, no coffee scored 88; the highest score was 87.5 (cottage Colombian pink bourbon from Escape in Montreal), and that was for a coffee the roaster said he didn’t think was 88, but given that it was a pink bourbon recommended by Jonathan Gagné, i was keen to try it. It was delicious. And I’m impressed that Escape didn’t try to oversell it.
The other candidates scored in a range of 83–87. The 83 may have once been a great coffee, but the coffee tasted old and baggy.
The process
I only accepted samples from roasters who offered credible reasons to believe the coffees might be 88. Several roasters offered coffees they were confident were 88 because “the green seller said it was 92” or “the coffee is so fruity that it has to be 88” or “it must be 88 because my customers love it so much.” I rejected those offers to save those roasters the time and expense of sending the coffee to me. It’s apparent that most roasters don’t understand the mechanics of scoring.
All coffees were cupped blindly, multiple times, by my friend Mark (Q Grader) and me. All cupping sessions contained coffees from multiple roasters. All cupping sessions included “anchor” coffees we had tasted multiple times, whose scores were consistent and known. Usually one of us had no idea what coffees would be on the table each day.
Calibrating with Sey
During this process, Matt from Sey Coffee reached out and offered some samples. Matt didn’t claim any of the samples would be 88, but he promised they would be tasty, and he was interested in calibrating, which I appreciated. I reciprocated by sending various samples to Sey. We compared our respective scores, as well as the scores of some importers with which Sey deals.
While my scores on all samples were a tad lower than those of Sey and the importers, we generally agreed on how we ranked various coffees. I believe everyone involved enjoyed and benefitted from the experience, though I doubt Sey enjoyed that baggy sample much :0 (sorry guys).
How roast quality affects score
When Ryan Brown and I ran Facsimile, a cupping-oriented subscription service, I occasionally sent multiple sample roasts of the same coffee to Ryan. Ryan preferred that all samples he received were not marked in any identifiable way (Not even country of origin). Every sample roast we cupped was well within the range of “typical” third-wave roast quality, ie nothing was grossly flicked or underdeveloped.
Our scores for a given coffee roasted a variety of ways would land in a 1.5-point range. Since then I have assumed semi-competent roasting could influence a cup score by up to 1.5 points. One way to look at that would be a “perfect” roast would capture the full potential of a coffee, while a flawed-but-not-awful roast would cause a deduction of up to 1.5 points.
Score inflation is real
As with everything, it seems, at some point marketers hijack something good, exaggerate claims of quality, and eventually make quality claims meaningless. Coffee scoring is no different. Green sellers and roasters are under competitive pressure to inflate scores. After all, if two green suppliers offer nearly identical coffees from a given origin at roughly the same price, but one importer scores theirs “88” and a competitor claims theirs is “86,” most roasters will be more inclined to buy the “88.”
In my experience, score inflation can be reasonably predicted based on the source of a score:
Coffee-review websites will habitually over-score by 6-9 points (no joke; if they scored conservatively, no one would send them samples)
Green importers will over-score by 1-5 points depending on the audience
Roasters inflated scores by an average of 1-3 points
Cup of Excellence scores seem quite accurate
CQI scores are accurate, by definition
Even if you disagree with my estimates, the simple fact that the main sources of public scores disagree by such large amounts mean the system is full of bias and inaccuracy.
The vast majority of the world’s roasters are quite small, and as far as i can tell, the majority of small roasters don’t sample roast and cup green samples blindly before purchase. A great deal of small and new roasters get their introductions to scoring from importers, which may compound score inflation over time.
A friend of mine who has been a Cup of Excellence judge since the beginning of COE says he is frustrated by scores creeping higher in COE competitions as well. I doubt score creep is nearly as bad there as it is in most of the industry, but that was still concerning to hear.
Thankfully the industry has a scoring “anchor” in the form of the CQI, which offers Q–grader scoring of coffees for a fee. Unfortunately that fee is rather high for most small roasters, but it would behoove roasters and importers to send the occasional samples to the CQI for calibration.
Scoring should be semi-logarithmic
I recommend interpreting seemingly linear scoring systems, such as that used in coffee, as non-linear. Although 88 is just over 1% higher than 87, I don’t view 88s as approximately 1% better than 87s; 88s are obviously much more than 1% better. Scoring is not linear.
I assume that over the course of cupping an extremely large number of samples (at least 10,000, preferably more) from a great variety of sources and price points, there should be approximately 10x more 87s than 88s. In my experience, that has been the approximate trend.*
Of course in a smaller sample size, or a set of samples with some sort of selection bias (eg you only taste washed coffees that cost above a certain price), this 10x relationship won’t hold. But it’s a good mental model; if you score only 2x more coffees 87 than 88, something is wrong. If you are scoring or offering 90-point coffees on a regular basis, there is a calibration problem.
*Think of this 10x trend as a bit like the stock market. The stock market may not return 10% in any given year, and its annual returns may fluctuate between -10% and +40%, but over time the market may return 10%. In 2018, I probably scored 2-3 coffees (all Kenyans) at 90 and 15 of them at 88-89. In 2022, due primarily to the collapse in Kenyan-coffee quality, so far I have scored nothing 89 or 90. Much like the rare years in which the stock market returns 40%, coming across coffees that score above 90 is so rare that it’s hard to know what their frequency would be over 100s of 1000s of samples over many decades. My guess is the 10x relationship would have decent predictive power up to about 93-94 points. To be honest, I have no idea what a 95+ coffee would taste like. If I ever taste one, I’ll probably cry and make that the last cup of coffee I ever drink. (Note to the haters: serve me a 95 and you’ll never have to hear from me again. Thanks)
The future of scoring
I fear that a few current trends will contribute to further score inflation:
The dramatic fall in the quality of coffee from Kenya and Ethiopia, historically the highest-scoring origins, over the past few years.
The continued explosion in the number of new roasters who learn scoring calibration from their green suppliers
The explosion in popularity of funky processing methods that are objectively dirtier than washed but somehow get a pass. (The phrase “clean for a natural” alone should make one suspicious.)
The first trend is most critical: Literally every 90-point coffee I have tasted over 30-year career was from Kenya. If there are no more 90-point Kenyas, “90” will lose its historical meaning, and today’s 87s may become tomorrow’s 90s. Once that happens, how will we score the Kenyans sitting in George Howell’s freezer? 105?
This slide is already happening, most obviously in 2022 due to “framing” effects and roasters “grading on a curve.” I’m frankly a little frustrated with the number of 88–90 scores roasters have claimed for their Kenyans this year. Literally twenty roasters this year have said to me a version of “I know Kenyans aren’t as good as they were, but I found one that tastes like the Kenyans of old.” Right, and everyone is a better-than-average driver :0.
Bias is rampant in all human pursuits.
If you want to know what a true 90+ coffee is, try some Kenyan from George’s freezer. It’s probably the only current, reliable source of such coffees. If you want to know what an 88 is, perhaps purchase a coffee that scored 90+ in a Cup of Excellence competition. I say 90+ because the competition coffees will have been scored when they were optimally fresh. By the time they land in your local roaster’s warehouse, they likely lost one or two points.
How to combat score inflation
If you are interested and can afford it, consider taking the Q Exam. It’s probably the quickest route to learning to score accurately.
Whether you are Q-certified or not, the most important practice is to calibrate with other experienced scorers who have no motivation to inflate the scores of the coffees you cup together. I didn’t know how to score until cupping with Ryan Brown, and I’m grateful to have been introduced by someone so competent and objective.
In recent years, I have found myself well-calibrated with Lance Hedrick, the entire, well-calibrated team (!) at Nomad in Barcelona, Jaroslav of Doubleshot in Prague, my daily co-cupper Mark Benedetto, Elliot at Steady State, and a few others.
Over time I hope to expand my circle of calibrated cuppers, as I believe it is the best way to prevent bias or score drift. In the future I plan to send samples to CQI periodically to calibrate with them. I welcome your comments.
It’s the most affordable way to get professional coaching for your roasting, and the group is 100% polite, supportive, and a pleasure to work with. Just having access to the vast archive of posts is worth the price of admission. Get more info HERE
WHY ROASTER AUTOMATION IS NOT YET A SUCCESS
Jul 20, 2022
Many people wonder why roaster automation is not better or easier. I’d like to discuss the current state of automation and the difficulty of creating successful automation. I define “success” as having identical results in the cup, such that a panel of expert tasters would not notice a material difference among several batches of a coffee roasted using automation.
I define full automation as a system in which the roasting machine manages the settings in an attempt to match a reference curve. This is distinct from semi-automatic systems such as Cropster Gas Control and Replay Assist, the Probat Pilot system, etc., which change gas settings at bean-temperature triggers based on preset recipes.
For clarity, Loring offers both systems: “profile roasting,” which is full automation, and “burner recipe” which is semi-automation.
Successful full automation requires:
An effective warmup and BBP. I’m a little tired of machine manufacturers claiming that *their* machines don’t require an effective BBP. Sure, it’s possible one of those manufacturers has rewritten the laws of physics, but it’s much more likely they have low tasting abilities or low standards for consistency, or their marketing departments are just dishing out BS.
A very well tuned PID.
Ideally, a fluid bed (Sivetz, Neuhaus Neotec, Typhoon) or indirectly-heated machine with recirculation (Loring, IMF, Brambati). Full, precise automation is always going to be more difficult in classic drum roasters due to the slow responsiveness of heavy metal drums combined with our current inability to measure drum temperature reliably.
Let me give some examples of why automation systems are not as precise as they seem at first glance. These examples are from roasts using Loring automation (profile roasting) with a competent BBP. While Loring has made the best attempt so far at full automation, I personally would not use it yet. These examples show that the best automation system out there still needs work. Of course, if these examples did not involve an effective BBP, they would look and taste even less consistent.
These are two 60kg Loring batches that followed a series of 20kg batches. The blue curve was the first of the 60kg batches, as astute readers would assume. The graph shows that the machine’s thermal energy was lower before the blue batch, which was to be expected, given that the previous batch was 20kg, and few roasters know how to create a successful “transitional BBP” when changing batch sizes (which is emphatically necessary, even with Loring.) These curves could have conceivably been identical with a proper transitional BBP, but those are 1) difficult to work out and 2) needing one brings into dispute the false claim that one can switch between batch sizes at will and the Loring automation will keep churning out identical batches (of a given batch size) regardless of those changes.
These two batches of course tasted noticeably different.
In the example above, at the very least, the PID should have used more gas, and kept it at 100% sooner and longer, in the blue roast, at approximately 1:30. Note that most of the time, when the automation chooses 100% gas, it is saying “I’m playing catch-up with the reference curve” which means it is usually not replicating the reference curve.
Here is an example of four batches using Loring automation. As you can see, replication was obviously more successful here. Factors that probably improved the replication were that the BBP was effective and didn’t have to compensate for a change in batch size, and the inlet-temperature curve was more consistent. That doesn’t guarantee consistent results, but it is an important piece of the puzzle. If we had better data quality from the first minute of each batch, I suspect the replication would look a little less successful,
Here is an example of excellent replication by a competent human roasting manually
Let’s up the stakes and look at replication of 9 consecutive batches by a competent human roasting manually. Note that some of the (very minor) discrepancies below came from changing the recipe in an attempt to improve results (in other words, intentional inconsistency, as you can see in the purple gas curve). The cup results were as consistent as the curves
Should you use full automation?
That depends on your standards. If your standard is “I don’t mind a small drop in quality and consistency to have a more labor-efficient system” then using it may make sense. If you say “the automation is more consistent than I am” then it also may make sense. Though in that case I’d prefer you seek a consultant to improve the consistency of your manual roasts (hint: choose the person who coined the term “between batch protocol” and developed the first truly successful BBP in the industry.)
Personally, I think more people should use semi-automatic (burner recipe) systems. Such systems are also labor efficient, but when combined with an effective BBP will generally yield more consistent, and likely tastier, coffee than the currently available automation systems.
The day will come when roasting automation is better than a competent human, but that day has not yet arrived.
I would rank the current state of roasting systems like this:
Best: competent human or competent human programming a semi-automatic system
Good: full automation
Bad: Not-so-competent human or not-so-competent automation
Cannot ever work consistently: any system that excludes an effective BBP
Thanks for reading.
Misguided Maillard Mania
Jul 13, 2022
If you read the coffee-internet enough, you are guaranteed to be more confused about roasting than you were before reading it. One of the more confusing bits of roasting advice I hear often is to “extend the Maillard phase” of a roast. The internet seems to believe more time in the Maillard phase has predictably beneficial results.
One challenge in roasting is when a roaster makes a single change from batch to batch, tastes a difference, and then declares that one aspect of that change (eg lower gas, lower ET, longer Maillard phase, longer roast time, etc) responsible for the change in flavor. Unfortunately, to be confident in the cause-and-effect relationship, one would have to make that change countless times, under controlled conditions, and make extreme efforts to rule out other possible causes of the new result. It’s painstaking work, which is why scientists often spend years and millions of dollars to study the effects of a small change in a system—often without clear answers despite the time and effort!
A few thoughts on why the standard Maillard-phase thinking is questionable:
Extending the Maillard phase necessarily means lowering and flattening the ROR, reaching first crack at a lower ROR, and increasing the risk of an ROR crash. There is no way to change just one variable in roasting— every change creates a chain reaction.
Extending the Maillard phase results in Maillard reactions happening at a slower rate. If you double the time in the Maillard phase, you may approximately halve the rate of Maillard reactions (this is a guess; I don’t know the exact change, but the relationship of Maillard phase time to Maillard products is not remotely linear, and no one really knows the relationship yet.) So, it’s possible the net change in Maillard products is negligible. I do not believe this issue has been studied thoroughly.
One can easily create two equivalent-tasting roasts of quite different total durations and Maillard-phase durations. For example, a 7:00 sample roast may taste nearly identical to a 13:00 production roast. This fact alone negates the standard Maillard thinking.
It is suspicious that no one ever seems to recommend shortening the Maillard phase. The implication seems to be “more is better.” Every good practice in roasting seems to have a “happy medium.” I can’t think of any instance where more is always better. This is a red flag indicating the proponents of longer Maillard phases are just repeating a trendy idea and don’t really know what’s optimal.
Focusing on balancing the time in various phases is extremely difficult and will almost necessarily lead a roaster to sacrifice curve shape, consistency, and predictability.
The bottom line is that roasting is complex. Most of what one reads online is false. Knowing a factoid about chemistry is not the basis for a roasting system. It’s an excellent practice to form opinions slowly, and only after exhaustive testing.
The group is incredibly affordable, supportive, and effective. Just having access to the vast archive of posts is worth the price of admission.
MacGyver is Alive and Well
Jun 11, 2022
I’ve had access to an old Probat electric sample roaster recently at a friend’s roastery. The machine is a bit of a dinosaur, and needed some serious MacGyer-ing (if you don’t know MacGyver, look him up; you’re in for a treat.)
Hundreds or thousands of roasters and importers use a version of this machine (and similar dinosaurs) to roast samples. While I’ve had delicious coffee from these machines, I’ve always been suspicious of their consistency. Now that I have had my hands on one of these machines for a few days, I’m certain: it’s impossible to roast consistently on these machines with their standard design. That is obvious from both the data and cupping results.
Those using these machines in their green-buying process need to be concerned that they may often reject coffees due to unrecognized roast issues. If you’re using one of these machines and not noticing their wild inconsistency, I implore you to roast 10 batches of the same coffee on one of these machines, and to cup the coffees blindly. Unless you’re roasting the s**t out of your coffees, the differences between batches should be obvious.
These machines have a several design problems:
• The electric heating elements have high latency and lack precision control.
• The airflow cannot be controlled with precision.
• The small outlet for exhaust air from the drum gets clogged with chaff easily and often.
• The standard temperature probe is poorly positioned and very slow.
• The barrels affect each other’s performance
I’d like to discuss how we tackled these problems to modernize the roaster and have a fighting chance at quality, consistent roasts.
Key: Dark green circle: Analog temperature probe.
Purple: our MacGyver’d probe and clip
Blue: Wattage meter
Bright green: Airflow knob
Red: Power dial
The electric heating elements have very high latency and lack precision control
What this means is that when you increase or decrease the power setting, the heating elements heat or cool slowly. How slow is slow? Very slow. Here’s an example below. This is between batches, empty drum, raising the power from 250 watts to 600 watts (the maximum is 880w). Note that it took more than one minute for the BT to begin to rise!
The power settings are controlled with a simple dial, as seen in the photo above (red circle). That dial offers little precision, as we learned when we plugged the machine into a wattage meter.
The airflow cannot be controlled with precision.
The airflow control is a small knob (bright green circle, above) one pulls out (increase) or pushes in (decrease) to adjust the airflow. For reference, the difference between insufficient airflow and excessive airflow is less than 2cm on the knob. Even a 1mm adjustment in the knob has a significant effect on airflow.
The small outlet for exhaust air from the drum gets easily clogged with chaff.
On the back of the machine is a narrow grate, with a 2cm square hole, where the air gets sucked out of the roaster. Unless one shifts to high airflow late in a roast, chaff builds up and partially blocks the hole, decreasing the airflow. Unfortunately, moving the airflow knob during roasting is risky, given that there is no way to adjust it precisely or consistently.
Not only that, but those without proper data logging may not notice the profound effect of shifting airflow. Below we increased the airflow at approximately 1:50. When you see a shift in data like that, it’s difficult to know what is really happening. My goal with this machine is to avoid changing the airflow at all costs.
Our solution to the airflow problem was a combination of “set it and forget it” and measuring the airflow with an anemometer (blue circle), a device that measures wind speed (which is different from airflow; windspeed is m/s, airflow is m^3/s.) With a reasonably precise anemometer, we are able to reset the air level with consistency.
Measuring air speed
The standard temperature probe is poorly positioned and very slow.
The stock temperature probe is in the back of the drum, and meant to measure environmental temperature rather than bean temperature. The probe is very slow and feeds to a mostly-useless analog gauge that changes temperature at a snail’s pace. Let’s just say one should not roast by ET alone, and analog gauges and roasting without proper BT data are very 1920s. I’m pretty sure none of us want to drink coffee the way it was roasted in the 1920s. Our solution was to mount a clip on the front of the machine to hold and guide a 2mm BT probe in the optimal location.
The barrels affect each other’s performance
While this machine is a two-barrel roaster, the barrels share the same exhaust fan and duct and cannot be used simultaneously without affecting each other. If you desire precise, predictable results, this is effectively a single-barrel roaster.
The results
After our MacGyver’ing, the roasts are more consistent, though not up to modern standards. At least now the machine won’t ruin many samples. We haven’t addressed the high latency of the heating elements, so that will impair precision. It is still challenging to prevent the chaff from sometimes clogging the exhaust port, but we can live with that for the moment.
Late edit: We have attached digital manometer to the machine to have continual air-pressure readings, so we’ll know immediately if the exhaust duct is slowly clogging.
Thanks for reading
Thanks to Mark Benedetto for doing most of the hard work, and to Vajra Rich and Boxcar Coffee for the help and hospitality!
A WEEK IN THE LIFE OF A ROASTING CONSULTANT
May 22, 2022
After a few weeks of hearing several online misconceptions about my work, I thought I’d take the opportunity to share what I do for clients on a weekly basis.
Being a roasting consultant is not about telling clients how their coffee should taste, telling them to end at a certain DTR, trying to influence them to roast lighter, etc.
Being an effective roast consultant is about giving clients the tools to consistently make their coffee taste they way they want it to.
When beginning work with new clients, I have them share information about their machine, installation, software, and current approach. There are almost always problems to fix related to machine tuning, warmup procedure, and between-batch protocol. It is necessary to solve those problems before attempting to optimize roast quality and consistency.
For example, in just the past week, I helped clients around the world with the following:
I helped client with a new Probat tune his burner, fan, and drum RPM, establish appropriate warmup and BBP, and troubleshoot some installation problems.
I helped a client learn how to find the optimal airflow level, between-batch protocol for his machine and batch size, how to log his warmups and BBPs in Cropster, and how to prevent massive flicks in his roasts.
I helped a client understand which noise in his temperature data is misleading, and which is relevant, as he was undermining his roasts by reacting to the misleading data.
I helped a client avoid spending money on a green loader he did not need.
I helped a client source a badly-needed digital manometer, manage a problem in his RORs, overhaul his BBP, and figure out how to manage problems caused by a merged chimney.
I helped a client improve his manual roasts so they are tastier and more consistent than his automated Loring roasts.
I helped a client tune his airflow and drum RPM to decrease conductive heat transfer and reduce roastiness in the cup.
I helped a client identify some problems in this green-buying system that were holding back his otherwise-excellent roasting.
All of that was in addition to working with dozens of clients on managing their roasts to be more consistent, and answering dozens of questions about roasting in my online roast-coaching forum.
Roasting isn’t just about cupping, or managing curves, or any other one thing. Anyone can roast a tasty batch here and there. Successful roasting is first about proper machine installation and tuning, second about having a system to ensure consistency, and finally about the day-to-day work of cupping and curve analysis and adjustment.
Boston masterclass announcement! Plus: Water chemistry, again
Mar 06, 2022
Boston Masterclass
I’m pleased to announce my first in-person roasting masterclass in three years. The class will be held in Boston on April 8 from 8-11am during SCA Expo weekend.
The class will include:
Cupping and discussion of a new Roast Defect KIt
Tasting of a few exceptional coffees, impeccably roasted
A focus on roasting consistency, including designing and mastering one’s between-batch protocol— the cornerstone of a successful roasting system.
Discussions of numerous advanced topics you won’t find discussed anywhere else.
Those who have previously taken my online or in-person classes are eligible for a 50% discount. Please email me (scott@scottrao.com) for a discount code.
I’m inspired to discuss water chemistry yet again after having some recent disappointing coffee experiences due to cafe owners not using appropriate water-treatment systems.
There is a lot of information online about water for coffee. It can be confusing — almost every cafe owner I have spoken to about water has been confused in one or more ways. I’d like to discuss some common mistakes and offer a simple roadmap to ensuring you are using the appropriate, high-quality water for coffee.
Cafe owners and coffee enthusiasts often:
Focus solely on TDS when evaluating water for coffee.
Take advice from water-system vendors
Think Reverse Osmosis systems are always the answer.
Don’t bother getting their water tested properly by a lab.
Let’s talk about each of those issues.
Focus on TDS
TDS does not determine whether water is good for making coffee. In my consulting work and my seminars, I have often asked roasters and café owners to tell me about their water chemistry. 90% of the time, they quoted an estimate of their TDS, but had no other useful information to share. Unfortunately, TDS by itself is not much of a guide to the quality of your water for coffee brewing. The one minor exception is when TDS is so low that hardness and alkalinity are also necessarily too low. For example, if the tap water at a cafe in lower Manhattan has TDS of 25, the hardness and alkalinity are too low.
As I have written about on Instagram, this website, my books, and most recently in Standart Magazine issue 25, alkalinity, not TDS, is the single most important data point when considering water for coffee. If alkalinity is too low, coffee may be too sour or sharp, and if alkalinity is too high, coffee may be flat, chalky, or lifeless. Depending on your coffee and taste preferences, an alkalinity range of 20-50 ppm is reasonable for most. Of course, there are important factors beyond alkalinity, but if one wants to simplify the discussion of water chemistry, I recommend focusing on alkalinity first.
Taking advice from water-systems vendors
I have nothing against people who sell water-treatment systems. They often know a lot about water chemistry and treatment options. However, regardless of how nice and well-meaning they are, their job is to sell — and upsell — equipment. It defies common sense to get your purchasing advice from vendors. For example, a former client was planning a cafe in Manhattan, where the TDS was the aforementioned 25 ppm, and a vendor had talked him into getting a $3000 RO system. I explained to the client that he would be better off adding minerals to his water than removing them. He was confused at first, but also relieved to only have to buy a $500 carbon-filter system.
Reverse Osmosis systems are not always the answer
RO systems are often the answer, sometimes counterproductive (see above) , and always expensive. If one needs an RO system, one may want one with a bypass system, depending on the tap-water chemistry. RO removes approximately 90% of the minerals dissolved in water. If the tap-water alkalinity is, say, 100ppm, before RO treatment, it will be approximately 10ppm after RO. In such a situation, a bypass or blend-back system can increase alkalinity and hardness to desired levels by blending the RO water with carbon-filtered tap water.
As usual, there is no one-size-fits-all solution.
Test, don’t guess
A *appropriate* lab test of your tap water will cost approximately $100 — $150 and is essential for knowing with confidence what the best water-treatment system is for your needs. I say “appropriate” because most lab tests do not measure all of the important analytes. Please ensure your test measures ALL of these things:
TDS
General Hardness (bonus points if the test measures Ca+ and Mg+ separately)
Alkalinity
pH
Fluoride
Chloride
Ideally, along list of various metals
In my consulting work, I frequently recommend a $125 lab test that measures over 30 analytes precisely and leaves nothing to doubt. With the test results in hand, plus the Langelier Saturation Index formula, I help clients choose the appropriate water system with complete confidence the result will be great-tasting coffee without scale buildup in machinery.
Introducing CupWise
Feb 13, 2022
For most of 2021, Ryan Brown and I offered Facsimile, a novel coffee subscription wherein each month we sent subscribers four coffees and Ryan and a coffee-expert friend cupped the coffees with subscribers via livestream. For many of us Facsimile filled a void created by not being able to cup with others due to the pandemic.
Shortly before we closed Facsimile, my friend Vladimir, a software developer, created an app to enhance the virtual tasting experience. I regret that Ryan and I didn’t have the chance to demonstrate Vladimir’s fantastic software for Facsimile subscribers. I told Vladimir I would like to help him introduce his software to roasters and coffee tasters everywhere.
What we were missing at Facsimile was interaction. The cupping videos were entertaining and educational, but opportunities for those cupping at home to interact with Ryan and friends was limited to a simple chat box.
With CupWise, Vladimir enhanced the chat feature and added a dynamic scoresheet. Tasters can enter their own scores and tasting notes in CupWise, and the software tallies the scores and creates word clouds from the tasting notes. The scoresheet is fully customizable, and roasting companies that host CupWise for their customers or for intra-company cupping can choose among the SCA Scoresheet, Cup of Excellence Scoresheet, or any custom format they wish. The CupWise host can hide scores until scoring is complete, and then “reveal” the average scores and notes. Vladimir has also added some fun statistical analysis, such as “polarizaton” that allow users to see how much agreement or disagreement there was about each score.
Sharing
One of Vladimir’s prime motivations in creating CupWise was his love of the shared tasting experience. There is something special about sharing and discussing great coffees with others. Sharing our impressions of coffees can be a bonding experience and helps us to learn and improve as tasters. Cupping with people like Ryan, Paolo, and Lance has made me a better coffee taster, and we are confident CupWise will improve our users’ experiences and skills.
See CupWise in action
I could try to describe CupWise all day, but it's best to see it in action to understand its power and how pleasant it is to use.
My partner Paolo at Regalia and I recently offered a new iteration of our Roast Defect Kit, and I thought cupping the RDK together, along with our friend Lance Hedrick of Onyx, would be a fantastic way to demonstrate CupWise.
Paolo, Lance, and I will demo CupWise live for RDK customers on Monday, February 21 at 10am NYC time (3pm in London). RDK customers will be able to chat, score, and enter tasting notes, and everyone else is welcome to watch the cupping and share the CupWise experience. The public can watch the event live, or saved, HERE.
Delicious Filter Coffee from an Espresso Machine
Sep 29, 2021
Filter 2.0
We’ve all tried to make good filter coffee in an espresso machine. It makes sense, right? Every espresso machine provides access to hot water, a spray head, a filter basket, and usually automatic volumetric dosing. Unfortunately, the flow and pressure provided by espresso machines is generally excessive for brewing great filter coffee.
If cafes could brew amazing filter coffee in an espresso machine, it would be the Holy Grail of brewing coffee by the cup.
After almost three decades of thinking and tinkering, I have finally found a method to brew extraordinary filter coffee in a (Decent) espresso machine in three minutes or less. I’ll call this Filter 2.0 until someone suggests a better name.
Much credit goes to Jonathan Gagné for sparking part of this idea with his long-steep aeropress technique, and John Buckman for his relentless improvement of the DE1 machine.
The pieces of the puzzle
The Long-Steep Aeropress Technique
Jonathan recently developed and wrote about his new aeropress technique that involves a steep of 10 or more minutes. The idea of improving and increasing extraction with a long bloom and removing the liquid extract gently from the coffee grounds is a cornerstone of Filter 2.0. In a cafe setting, I would limit the bloom phase to two minutes. At home, it’s worth experimenting with much longer blooms.
The Filter Sandwich
In May, 2019 I posted onInstagram about my “filter sandwich.” Many years earlier, Andy Schecter had posted online about putting an aeropress filter under his espresso pucks to absorb fats and possibly prevent his blood cholesterol from rising. Andy reported the interesting side effect that the filter allowed him to grind finer and extract (1.5%?) higher. In 2019 I built on Andy’s idea by adding a filter on top of the puck, in an attempt to decrease channeling. The filter sandwich decreases channeling, increases extraction, and also maintains puck integrity when applied pressure is released during the bloom. In the case of Filter 2.0, I recommend using a bottom filter with very small holes of 1—2 microns. More-porous filters will yield coffee with less clarity and possibly more astringency.
The Blooming Espresso
in late 2018, a few months after receiving my DE1, I created the “Blooming Espresso” profile, in which pressure and flow pause for 30 seconds (without opening a valve) to allow the grounds to “bloom” before percolation removes liquid from the puck. The bloom improves extraction quality and quantity, especially from the lower layers of the puck. Filter 2.0 is a filter-coffee variation on the Blooming Espresso with a longer bloom phase.
The Profile Building Capabilities of the DE1
The Decent allows a user to build profiles with as many steps as desired, with features such as temperature profiling, flow control, the ability to move from one step to the next based on a trigger (such as reaching a pressure or volume target) and countless other next-level options. In this profile I used 90°C during preinfusion and 85°C during percolation, a two-minute bloom phase, and a flat 3 ml/s flow rate during percolation. As a safeguard, I set a “pressure limit” of 3 bar during percolation, just in case my grind is too fine. I’m not yet sure whether that is necessary, but it can’t hurt.
The Process
Insert a two-micron 55mm paper filter in the bottom of a clean portafilter basket
Rinse the filter and basket with hot water or latch and flush with hot water.
Fill the basket with finely ground coffee, not quite espresso grind, but far finer than any filter grind. I use settings 2a—2m on a Baratza Forte depending on the coffee. You might try something like #3 (out of 11) on an EK43 or #3 on a Ditting. I use 20g—22g in a 24g basket in order to have enough room for the Flair58 puck screen.
Distribute the grounds, ideally using the Weiss Distribution Technique
Tamping is optional :0. Take a breath. It’s ok to not tamp this.
Set a metal mesh screen such as the Flair58 puck screen on top of the grounds. Ensure the filter is level.
Latch the portafilter on the espresso machine and pull the shot.
Preinfusion: I set the pre-infusion time just high enough such that the entire puck will be saturated a few seconds after the preinfusion flow stops. If you are using a Bluetooth scale with the DE1, you can set the pre-nfusion time longer and set the maximum weight to something like 2g, which will cause the profile to move on to the bloom as soon as the scale senses a few drips. An easier solution might be to figure out the number of ml at which you’d like preinfusion to end. Experienced DE1 users will know there are several more sophisticated ways to program just the right amount of preinfusion.
Bloom (pause): As noted, the bloom time is flexible. For use in a café, I think two minutes is adequate. Longer bloom times are marginally beneficial. For use at home, you may want to experiment with much longer bloom times.
Percolation (flat flow): my standard flow rate is 3 ml/s. I find a higher flow rates increase fruitiness of coffee but also increase the risk of astringency. The flow rate should ideally be scaled to dose size. For example, if you are using a small basket and does such as 12 g, you may want to use 2 ml/s but 3 ml/s would be appropriate for an 18g dose. Flow rate should scale more or less in proportion to the depth of the coffee bed .
Pulling a shot
Note that I limit these shots to 5:1 ratios. The shot you see here was made using 20g in a 24g basket with a Flair58 filter on top of the grounds and a 55mm, 2-micron filter under the coffee bed. To mitigate the risk of astringency, I don’t usually exceed a 5:1 ratio. After the shot is complete, I dilute it with hot water to my desired brew strength. The end result is a 20g dose and 100g extraction diluted with 225g—250g of water to yield a 23%—26% extraction with 1.4%—1.5% strength. Of course, all of these numbers are adjustable to taste.
If you sense astringency, consider improving the puck prep, grinding coarser, or putting a finer-mesh filter under the puck.
So, how does it taste? It tastes like an incredibly-well-made filter coffee, the kind you hope the barista will make for you, but you rarely get, when you order a pourover. I recommend tinkering with the Filter 2.0 profile to influence acidity and fruitiness and tone down undesirable flavor. For example, one might lower the temperatures when using darker or defective roasts. One could extend the bloom phase to increase extraction when not in a hurry. And one could increase the percolation flow rate to enhance fruitiness, though that may increase the risk of channeling.
What’s Next?
I hope this post inspires others to give this a shot (sorry) and make improvements. I have only been using this profile for a few days, and I’m sure others will make many incremental improvements.
I have one caveat, however: please do not try this shot with a standard, traditional espresso machine. It’s just not going to work well. It is possible to approximate this profile with a lever machine or with an E61 machine with low line pressure, though it’s easiest and best with the DE1.
Every part of this profile is important and works together to produce a great end result. Before experimenting or modifying, please test this profile the way it was designed, using the filter sandwich, DE1, preinfusion, long bloom, low temperature, and low ratio. Skipping or modifying any of these parts is likely to damage extraction quality and enjoyment. Thank you. NB for DE1 users: John has added this profile to the profile library on the DE1. Simply update your app and you will see it.
Should you omniroast? The answer is not so simple
Sep 18, 2021
Roasters often debate the merits of “omniroasting” but I have never heard someone discuss what I think is the most important determinant of whether one should omnniroast: quality of espresso extraction.
Omniroasting refers to using the same roast profile for both filter and espresso. Of course, espresso roasts have traditionally been darker than filter-coffee roasts. And I am all for using lighter-than-traditional roasts for espresso. But with the advent of third-wave roasting and the sometimes obsessive desire of roasters to roast as light as possible — whether they can do so successfully or not — many have decided to roast their espresso coffees as light as they do their filter coffees.
Unfortunately, espresso made from very light roasts is often unpalatably sharp, sour, and imbalanced. However, it is not always due to the roast, it is often due to the espresso extraction.
Until the past few years, a “god shot” was something coffee pros expected to experience perhaps once per year. I don’t fault baristas — or a deity — for the infrequency of god shots. I fault the limitations of the equipment we have had at our disposal until now.
Prior to using the DE1 from Decent Espresso, I had tasted perhaps five truly great espresso extractions in my life. For 20+ years, almost every espresso I tasted was imbalanced, too sharp, and too bitter, and usually astringent. The exceptions were usually shots made from low-acid coffees, but those coffees were not of good enough quality for me to enjoy as straight espresso. However, it makes a lot of sense that darker, low-acid coffees have been the rule in most countries for many decades. Every other type of bean pulled as espresso was guaranteed to be too sharp and imbalanced for most palates.
The first day I pulled blooming espressos on the DE1 was the first time I tasted several great extractions in one day. The blooming espresso profile consists of a flow-controlled preinfusion (note: there is no such thing as preinfusion controlled by pressure) followed by a 30-second “bloom” during which the flow stops but the machine applies a modest pressure on the puck to prevent it from expanding or losing its integrity. With the right grind setting, a few drops will fall during the bloom. After the bloom the machine executes a 2.2 ml/s flow profile to extract the coffee. Much like when making a pourover, but more dramatically, the bloom phase increases and improves the temperature of the lower layers of the coffee bed, ensures all of the grounds are saturated with liquid before extraction, and increases extraction level. The higher, more uniform extractions of the blooming espresso soften the flavor profile, decreasing sharpness and bitterness. They also produce very high extractions, allowing one to use less grounds if desired.
A well-executed blooming espresso shot approaches the extraction quality of good filter coffee.
With the blooming espresso and similar profiles on the DE1, as well as with the allongé, another high-extraction profile I have written about extensively, I happily (and exclusively) pull shots of very lightly roasted washed coffee. While baristas have historically avoided shots of lightly roasted Kenya because of their inevitable sourness and sharpness, lightly roasted Kenya and Ethiopian coffees are now my go-to espresso beans, just as they are for filter coffee.
So, should you omniroast? If you are using something like a Mazzer Robur and an LM Linea, without true preinfusion, definitely not. If you are using a better grinder such as a Mythos with a machine that offers proper preinfusion and/or pressure profiling (E61, Strada, etc) you may be able to pull nice shots of light omniroasts. And if you have a DE1, you can mold the flavor of your espresso to your liking.
My advice is to not allow the platonic ideals of super-light roasting or omniroasting to get in the way of producing the best end product. I believe it is best to adapt to, and optimize for, the limitations of your equipment, or upgrade your equipment, and roast appropriately for it.
One simply cannot discuss omniroasting without considering the quality of espresso extractions. Comments always welcome.
I selfishly started Facsimile because I wanted a good excuse to cup with experts from around the world. We recently completed the fifth live cup-along, and I’m in awe of how much I’ve learned already.
I took a moment to reflect on the past several months and a handful of the takeaways. Here’s what I found.
1.Consistency is king
The purpose and namesake of Facsimile is to provide coffee enthusiasts an exact copy of the experience of cupping side-by-side with experts. We take efforts in preparation to ensure that each set of samples is identical. We provide as much instruction as is reasonable so that each cupping bowl of a sample tastes the same.
But it’ll never be precise, and we know that. However, you can control that each of your samples is prepared and handled the same way. Ground the same, brewed the same, and evaluated the same.
This is especially important on any given cupping table of green samples, but also important from table to table, session to session. Eliminate all variables apart from the samples themselves, and you’ll have a more successful evaluation.
A song may sound different on different speakers, but you should still be able to tell the difference between “Hey Jude” and “Smells Like Teen Spirit,” no matter what you have available to you.
2. Sensory evaluation is comparative evaluation
As a coffee brewing method, cupping is inherently cynical. It readily trades quality of brew for reproducibility and assumes that defects are everywhere if you just look close enough.
Yes, cupping is designed 1) as an easily repeatable extraction process, and 2) as a means of more easily detecting defects and inconsistencies (by way of several, smaller brews).
But there’s a pleasant, perhaps unexpected byproduct of this pessimistic outlook. Cupping is hands down the best way to brew many samples at once, and brewing many samples at once creates a magical context for comparative tasting. This is no small matter. Drink a cup of any coffee and you will be immersed in its qualities, you’ll be very much seeing its trees, and not the forest. Give yourself several other coffees to taste before and after, and you’re giving yourself a broad view of the forest.
This comes up again and again during our live cup-along: the first sample often just smells like and tastes like, well...coffee. This isn’t some affliction of the novice. With my 20 years of coffee tasting experience, I habitually return to sample #1 to complete my evaluation. If I ever need to cup just one sample, I’ll find one or two other samples to put on the table alongside it to be sure that I obtain the benefit of comparison.
This is also why I cup incognito and scatter bowls across my cupping table. I gain very little from knowingly tasting the same sample three or four times in a row. I gain so much from unknowingly tasting them throughout the table in different contexts. (After I grind each sample, I place the same color sticker under each bowl and on the card or bag with the coffee’s information. Having done this to every sample’s bowls, I randomly scatter the bowls around the table, then reassign them numbers for my cupping notes. Upon completion of the evaluation, I check the sticker of each bowl, sort out any discrepancies, and finalize my scores.)
3.Official cupping forms aren’t used much
I’ve been using a Cup of Excellence form as long as I can remember for all coffee scoring. But, I don’t use it properly. I rarely score all individual attributes, and instead hack it to fit my needs. This was reinforced by the habits of the Stumptown cupping lab circa 2011, where we all did the same.
I had a sneaking suspicion that I wasn’t alone and that there were other cuppers who didn’t use official cupping forms at all, or who used them in a hacky way, or who had designed their own.
If the Facsimile guest cuppers are any indication, I underestimated. While most of them have formal cupping training of one sort or another and all of them know how to use a standard 100-point scoring system and the SCA cupping form, not one of them routinely uses an official cupping form for evaluating green coffee.
Scott Rao tends to capture notes and intuit a score based on a nearly unconscious evaluation of the cleanliness, sweetness, acidity, and flavor. Gabby Wright is Q certified and has memorized the SCA cupping form. When she scores, she uses a notebook to capture coffee notes and a final score. Zakiya Mason and Charles Babinski use a proprietary form that separates sweetness, acidity, and then buckets everything else under “structure”. Petra Veselá and Gwilym Davies use a 6-point smiley-face system modified from barista competition scoring, with which they have abundant, diverse experiences.
And yet, I have been in sync with these experts across a variety of origins and qualities in cupping after cupping, in coffees ranging from 82 to 89 points.
4.Be clear about your goal for each cupping
A reason why official cupping forms are seldom used is that they don’t expressly address the goal of a given evaluation.
For example, Zakiya and Charles were coming to the cupping table looking for coffees they’d be proud to share with visitors of their cafés. The customized form they use instead of an official form is designed to answer--and explicitly asks--the question, “Would you serve this?”
Gabby cups with her roasting clients in mind. Scott cups to better understand how to approach roasting and extraction. Petra and Gwilym primarily cup in order to evaluate the success of their roasting.
If your goal is to give the coffee an official SCA or Cup of Excellence score, then I know just the cupping form for you to employ. If you’re cupping to purchase, to understand how a coffee may fit into a blend, or to showcase a range of qualities to a customer, consider how that should affect your approach.
5.Cupping results are a form of communication
Sometimes the most obvious detail can be lost in an elaborate, intimidating ritual. For example, it took me an embarrassingly long time to fully grasp that coffee processing techniques--washed, natural, and nearly every other version--were each created with the straightforward goal of preparing coffee to be stable for storage and transit.
Cupping may appear to be a series of steps that you need to precisely follow to be “doing it right.” While there’s some truth to this, and certainly unavoidable parts of cupping, the steps are a means to an end, and that end is an accurate, concise description of a sample that can be understood by someone else.
Cupping results are a form of communication, whether the recipient of the message is a farmer, importer, roaster, customer, or even your future self who won’t otherwise remember what it was like to taste that coffee.
The magic of cupping with others (as we do in Facsimile) is the value of having that communication in real time while the cups are still warm and in front of you.
Best Practice Espresso Profile
May 18, 2021
The most impressive, productive (and sometimes over my head) discussion about espresso these days is on the private Decent Diaspora forum. One of the wonderful things about the Decent community, besides its civility, is the way a group of impressively intelligent people collaborate to expand our understanding of espresso extraction.
A recent development has been John’s new “Best Practice” espresso profile. Although it is a work in progress, as all of our profiles are, this development is worth discussing. If you’re not familiar with the Decent’s graphs, bear with me, it’s a lot simpler than it looks at first.
Longtime readers will notice this profile looks a lot like my “Blooming Espresso” profile. The Best Practice Profile includes a few improvements on the Blooming. The improvements come primarily from work by Damian Brakel and Jonathan Gagné.
Quick fill of group head at the start of preinfusion. Preinfusion starts hotter (not shown) than the rest of the shot, to compensate quickly for the cooling effect of the room temperature puck.
Low pressure preinfusion, to assist capillary action in fast, even wetting.
Pressurized bloom to maintain puck integrity. (The low-pressure bloom of the Blooming Espresso can work brilliantly but offers a greater risk of channeling when pressure is reapplied.)
Softened pressure rise to avoid channeling that a steep rise can cause.
Extraction phase switches to flow profiling for automatic channel healing.
Extraction phase has a linear flow-rate ramp over time, to keep constant water contact time, instead of using pressure profiling to approximate this.
Other notes:
The extraction phase uses a pressure limit, so as to never go above the set maximum pressure of 9 bar. This “failsafe” is now a feature many of us for all shots on the DE1, to salvage cup quality if the grind is a little too fine.
The BPP will soon implement Jonathan Gagne’s “adaptive profile” idea, in which the extraction phase will decide the steady-state flow rate relative to flow at peak pressure. This adapts the profile to the grind size, using
Accurate stop-at-volume closely matches scale weight, because of a fully successful preinfusion.
A smooth puck resistance curve is achieved.
While this may be a lot to digest, rest assured that when using the Decent, you can “set it and forget it.” If I were using a DE1 in a cafe, I would use this profile all day, and only adjust the grind as needed. While the Decent’s brain is complex, the user interface couldn’t be simpler.
Some of the "best practices" here were originally discovered on traditional machines:
- Several machines (such as Kees' Idromatic) have a quick fill, followed by a soft-pressure-rise feature built into the group, and manual lever machines have done this for years. (one great thing about the DE1 is it can mimic any feature from any other machine.)
- Pressurized preinfusion is fairly common in traditional machines, but to my knowledge, no traditional machine implements this by measuring puck pressure. Instead they measure pressure-behind-a-flow-constrictor, which gives different results.
To answer the inevitable question, yes, these shots can taste amazing.
I’d love to know your thoughts about this.
*******
Would you like to improve your cupping skills while enjoying delicious coffee? Subscribe to Facsimileand cup along live with Ryan Brown and his guest coffee experts each month. We offer a money-back guarantee, and no commitment is required.
Does the difference in the body of various coffees matter?
May 09, 2021
Does the difference in the body of various coffees matter? The answer may seem obvious, but bear with me.
Let’s say you drink only specialty-grade coffee. How much does body vary from one bean to another? Not much, I would posit. Natural variation in body among different coffees is modest, but the ability to change body through roasting and brewing is much greater.
I believe that most perceived differences in body at the cupping table are due to not meticulously weighing both the ground coffee as well as the water used in cupping. While some modern green buyers and roasters weigh their cupping water, that is not a universal practice, and it was rarely if ever practiced until about fifteen years ago.
What is body?
Body is the tactile sensation of coffee on the tongue, produced by a combination of viscosity and insoluble particles. Body is related to mouthfeel, but most authorities attribute body primarily to insoluble particles, and mouthfeel to the presence of oils. Mouthfeel relates to the sensation of “butteriness” produced by suspended oils in coffee. Interestingly, body does not seem correlated with the proportion of fines various coffees produce when ground.
Body is indirectly related to brew strength as measured by TDS. I say indirectly because TDS is a measurement exclusively of dissolved particles, and body is produced by insolubles. But generally speaking, for a given brew method, increases in TDS correlate with increases in body. TDS is a measure of density, and a denser brew produced by the same method will typically have more body.
How to influence body in coffee
There are four ways I can think of to influence the amount of body in brewed coffee:
choice of green coffee
roast level and development
brewing method and filtration
brewing ratio
Choice of green coffee
The choice of green coffee probably has the least capacity to affect body. Recently I was talking about body with Ryan Brown, cofounder of Facsimile Coffee. Ryan noted that body has probably never been a decisive factor him when buying green coffee. That remark struck me and sparked my interest in writing this post.
While coffee origin and processing can affect body, the choice of origin or processing has less impact on body in the cup than do the following factors.
Roasting and body
Roast level and development, as well as the ratio of conduction to convection used in roasting influence body. Darker roasting, greater development, and coffee roasted with more conduction have the capacity to increase body. Perhaps few of us would choose to roast darker simply to increase body, but learning to increase roast development without roasting darker can be a useful tool for manipulating body as well as flavor.
Brewing method and filtration
The choice of brewing method, and especially filtration, have the greatest capacity to influence body. Immersion brews and other unfiltered brews produce the most body. Percolation methods in which the coffee bed acts as a form of filtration to trap fine particles produce less body. Percolation methods using filters with low porosity and high capacity to trap fines produce the least body.
Brewing ratio and strength
Increasing the ratio of grounds to water and/or increasing brew strength (density), all else being equal, will increase body.
The bottom line
Returning to the original question, it seems reasonable to ignore or discount body as a factor when choosing green coffee. Small changes in brewing method, recipe, and filtration have the capacity to alter body far more than one could achieve by choosing different green coffee.
Interested in improving your cupping skills while enjoying spectacular green roasted flawlessly?
Subscribe to Facsimile. We offer a money-back guarantee if you don’t love it.
"Solubility matching" and blending coffee
Mar 09, 2021
A few years back there was a trend called “solubility matching,” an attempt to blend coffees of similar solubility. The idea was appealing but never seemed to gain traction or improve the quality of blends. What is solubility? And what is solubility matching? And does it matter?
Solubility is a property referring to the ability for a given substance, a solute, to dissolve in a solvent. Simple enough. It is estimated that just over 30% of a coffee bean’s weight is soluble in hot water. Roast development, coffee variety, and, I believe, coffee density, among other factors, influence the solubility of a particular bean.
Underdeveloped roasts tend to be less soluble than well-developed roasts. Very dark roasting decreases solubility by burning off some of a beans soluble mass. The most soluble roasts seem to be well-developed, light-to-medium roasts.
I have reached extractions as high as 28%—29% (most often with Kenyan and Ethiopian coffees) using extraction methods such as the Blooming Espresso, Vacuum-pot brewing, and the Tricolate brewer, all of which offer opportunities to achieve near-complete extractions. I imagine I’m still a few percentage points away from “complete” extraction, or exhausting a coffee’s solubility, without resorting to hydrolysis, as many instant-coffee manufacturers do.
“Solubility matching” is the appealing idea of blending coffees with similar solubilities. I believe the assumption behind solubility matching was that blending coffees of similar solubilities would improve flavor or extraction level. One difficulty of solubility matching was that it severely limited what coffees one could blend together. Recent efforts to revisit solubility matching have confirmed for me that blending two coffees of different solubility levels merely creates a resulting coffee with an extraction level that is approximately the weighted average of the extraction levels of the two blend components, and a required grind setting that is likewise similar to the component’s weighted-average grind sizes. (Jonathan Gagné recently confirmed for me that blending two coffees creates a blended version of their particle-size distributions.)
As for flavor, I have never found a formula or a shortcut to creating a great blend. Solubility matching hasn’t improved my results. Given that green coffee is always slowly fading and roast batches often vary in quality, I believe informed trial and error, with lots of blind tasting, is still the only practical way to create and manage a great blend.
The only shortcut I use to blend coffee is the well-known “spoon method”: pour a cupping bowl or brew a cup of each blend component you are considering using. Spoon some of each blend component into a separate, clean cup. For instance, if you have three blend components and want to taste a 3:2:1 blend, blend three spoons-full from the first cup, two from the second cup, and one from the third cup, and taste that. Repeat and taste with different ratios from each component.
I'd love to hear from you if you would like to share your experience with solubility matching and blending. Thanks for reading.
Every Green Buyer’s White Lie
Feb 18, 2021
How the belief in a supposed skill made me miss out on great coffees
There’s a little story I started telling myself after I had been buying coffee for just a couple of years, and it went like this:
I can taste green coffee through the roast.
What does this even mean? It means that I believed I could accurately evaluate a coffee’s qualities and score regardless of how poorly it was roasted, provided it wasn’t charred beyond recognition. It means that I believed the score I gave the sample wouldn’t change if I cupped a different roast of the same green.
The story served me well; it certainly helped me avoid buying bad coffees. But the story is a lie, and I’m sure it made me miss out on a great deal of great coffees.
First, let’s explore why I told myself this lie. To be an effective buyer of green coffee, you have to build a deep understanding of what factors cause green coffee to taste as it does. You learn about terroir, soil, varieties, harvest, processing, and drying above all others. You grow an intuition for how changes in these crucial steps play a part in the samples you’re cupping.
On a given table of samples, you can reasonably assume that they were all roasted similarly enough that roast is not a variable. All of those other details of the green coffee are what make up the differences in the cup.
But there’s more than that. Many green coffee buyers travel all over the world tasting coffee. Often, they have little or no control over how samples are roasted, even if they fully appreciate the impact of roasting on a cup’s score.
I’m not alone in feeling this way. I can count on one hand the number of green buyers who believe that roast is important in their sensory evaluation of a green coffee. I would need several hands to count the number of coffee buyers who believe they cup through roast.
Recently, I cupped a Rwandan sample provided by Atlas while looking for offerings for Facsimile. Here are my raw cupping notes:
83.00
fragrance/ aroma: vegetal, chocolate?, molasses
liquor: unsweet, vegetal, raisin, nice body, sweet + bright when hot, still vegetal as cools
Not sure if you caught this, but I wrote “vegetal” three times and wrote the coffee off completely. Also note that I do not mention the roast at all. There was nothing obviously wrong with the roast during my evaluation.
But Scott Rao, who closely monitors the ROR curves of all the coffees I received, reached out when he saw my score. He pointed out that, due to no error of the person sample roasting, the reliable Mark Benedetto, there had been an issue with the roast.
Fortunately, the good people at Atlas were willing to indulge a little experiment, and sent me more of the sample, despite my explanation that I’d be unlikely to purchase the coffee. (Thank you, Chris Davidson!) A new sample, properly executed, arrived on my table:
A three-point difference for this experienced cupper because of roast? This experience has completely changed my understanding of green-coffee evaluation.
For one, it’s why we decided that all Facsimile products include a roasted sample. We had been considering offering a green-only version, but reconsidered after realizing that even the most skilled and experienced sample roasters using the best equipment can make a mistake, especially in their first batch of a new coffee.
Two, I accept that if I don’t like a sample, it might be the roast, not the green.
Three, you will no longer hear me say that I cup through roast. I don’t believe that anyone else can either. If anything, this lie held me back from a deeper understanding of when a roast is not appropriate for green coffee evaluation.
Finally, it has helped me considerably to have consistent ROR curves in my sample roasts. Great roasting should not be exclusive to production roasting.
To Be a Great Coffee Taster
Feb 13, 2021
A few years ago, I wrote the first book about the coffee buying role, Dear Coffee Buyer. I explained my motivation to share my experience as plainly as I could in the preface:
I’ve made my fair share of coffee-buying mistakes. Some of them were likely unavoidable, but others could have been sidestepped if I had only had access to training for the job. Know-how and skill-building for the position, like an urban legend, has been passed on through the oral tradition. If you don’t work directly with someone who has been buying coffee for years, you just have to figure it out on your own. My goal is to help you avoid the mistakes I made and to shorten your path to proficiency in coffee buying as quickly and painlessly as possible.
I’m satisfied with the effort to share what I know about coffee buying, but there’s a limit to how much you can learn from reading a book.
Since its publication, it has become clear to me what I didn’t--what I couldn’t--include in Dear Coffee Buyer.
To be a truly great coffee buyer, you have to be a great coffee taster.
To be a great coffee taster, you have to cup with other, experienced tasters. You have to cup the same roasts of the same samples, brewed with the same water at about the same time. “Go out of your way to cup with others,” I write in Dear Coffee Buyer. “Getting someone else’s opinion on a cup or sample--even, or especially, if it’s different from your opinion--is incredibly valuable.”
Unfortunately, this work cannot be done alone or in isolation. It cannot be done with your importers or other suppliers, because (please keep in mind) they’re trying to sell you something.
Typically, this could be done in-person, but this isn’t always possible, and for the past year, has been very nearly impossible.
Scott Rao and I are launching a cupping subscription designed to help you become a better coffee taster. Our goal is to provide you with an exact copy of the coffee we’re tasting so that we can cup them together, live and online.
Each month, you will receive several unique coffee samples, expertly sourced and roasted.* I will evaluate the samples online while you taste along at home and compare notes, live or in your own time. We’ll invite guest cuppers to share their takes on the same coffees you have brewed in front of you. You’ll have the chance to improve your skills while you gain insights about origins, processing, and samples.
It’s called Facsimile, and it’s available in limited quantities now.
*This may sound glib or superficial, but we’re dead serious.
We could wax poetic about how we collectively come with decades of green sourcing and roasting experience, or how we’ve written definitive, seminal books in our fields, or how we promise nothing short of exceptional coffees roasted flawlessly, free of any defects.
But we’ll make it simple: We guarantee your satisfaction. If you’re not happy we’ll refund your money in full.
CUP SCORE INFLATION
Jan 18, 2021
Recently a friend and I discussed the viability of starting a niche business selling green coffee. We decided not to do it, but one of the interesting issues to come out of our discussions was cup-score inflation.
Part of our business model would have been to offer customers our coffees’ cup scores. However, scoring our own coffees would present an obvious conflict of interest: competition would pressure us into either inflating our cup scores or risk losing business to competitors who inflated the scores of their coffees.
For example, one of my friends who is a home roaster and Q-grader purchased numerous coffees from a well-known green supplier. He scored all of those coffees 3––6 points lower than the scores provided by the green seller. The most egregious example was a Kenya rated 91 points by the importer, which my friend rated a generous 85. This is not a mere quibble. You should know a 91 when you taste it. You will remember where you were and who you were with. An 85, on the other hand, is not memorable. These scores are not close.
Another example: last year I asked several importers to send me only samples of coffees rated 88 points or higher. The vast majority of samples I received were 85––86 points. While there is nothing wrong with 85-point coffees, it is difficult to mistake an 85 for an 88.
These are all examples of what I think of as the “slippery slope” problem marketers often face: if you are completely honest about the quality of your product but your competitors all exaggerate the quality of their products, you will lose to those competitors. Once one competitor makes exaggerated quality claims, it becomes nearly impossible to avoid inflating your own claims of quality. Over time, the claims of almost all surviving competitors are inflated.
Even when importers score coffees accurately, they often publish the score of a coffee when it was at its best, say, based on a pre-ship sample, and they do not re-score the coffee after it arrives, or later as the coffee fades and loses quality. Some coffees can easily lose a few points in a matter of a few months due to shipping conditions, storage conditions, excessive moisture content, or even the microbes used during fermentation. (See Chris Feran’s excellent post about microbes and coffee fade here.)
Ideally, one hopes roasters will be “educated” enough to evaluate quality accurately, and then choose green accordingly, but in my experience working with newer and smaller roasters, that is often not the case. Many of my smaller clients don’t sample roast or request enough green samples before purchasing a coffee, and they over-rely on green sellers’ scores to guide their buying. This dynamic may train less-experienced roasters to score coffees too high.
In the past year, my smaller clients have overrated the score of almost every roast sample they have sent me, usually by 2––3 points, but sometimes as much as 5––6 points.
Please don’t misunderstand me: I do not think green sellers are any less honest than other people. They are simply adapting to an unfortunate dynamic in the industry created by a combination of competitive pressure and having inexperienced clients. I wish they would be more accurate and up to date in their scoring, but I also wouldn’t want to be in their position.
What’s the solution?
I won’t pretend to have the definitive solution to this problem, but here are some suggestions that may help less-experienced roasters make better green choices.
Take the Q-certification course. It is perhaps the only industry-sponsored course worth the money.
Train in person or remotely with an expert. If your goal is to improve your cupping and scoring skills, this is a more cost-efficient option than taking the Q course. I don’t consider myself expert enough to offer such training, but if it interests you, send me an email (scott@scottrao.com) and I’ll connect you with someone who is.
Always sample roast, and cup blindly. Ideally, use more than one cup of each sample, and scatter the duplicate cups around the table so you don’t know where each coffee’s twin is. If you find you often score the duplicate cups differently, you know you have some work to do.
Always cup more than one type of coffee at each cupping session. This is great advice from Ryan Brown, who told me he never cups a coffee by itself because he prefers to have a reference coffee on the table. And of course, ideally that reference coffee is cupped on a table with many samples.
Try to cup with seasoned professionals when possible (and when we’re not in a pandemic.)
photos by Adam Friedlander (@a.frieds)
2020 HOLIDAY COFFEE-GIFT GUIDE
Dec 08, 2020
As we enter the holiday season, I thought it would be nice to make some gift recommendations for the coffee enthusiast in your life. I admire and enjoy all of these items personally, and strongly recommend them. Please note that I have no financial interests in any of these products, other than my own book and the Decent Espresso Machine.
The World Atlas of Coffee by James Hoffmann is simply the best all-around book ever written about coffee. James has recently updated the book’s data for the producing countries he discusses, and he has added sections such as one on home roasting. The book is available in English, German, Chinese (Simplified and Traditional), Russian, Korean, Japanese, Norwegian, Thai and even Italian!
Barista Hustle Subscription Whether you’re a home barista or work in a cafe, there is no better way, especially during a pandemic, to deepen your barista skills than by taking the Barista Hustle online course. Barista Hustle, led by Matt Perger, is the world leader in making geeky baristas even geekier. If you’re going to learn, learn from the best.
If you’re in Europe and want to order some special beans for a loved one, I recommend the honey-processed Costa Rican Geisha Sumavafrom one of Europe’s best and most underrated roasters, Doubleshot in Prague. Nothing says “I love you” like a bag of Geisha, right? (But if I send you a bag of natural beans…)
I’ll say it out loud: The Espro Bloom is my new favorite pourover brewer, despite the funny-looking filters ;). The Bloom is the fastest pourover brewer I’ve ever seen, it makes delicious coffee, and is a pleasure to use. I can’t recommend it enough.
The Flair Espresso Maker is a wonderful new manual espresso maker. Just fill it with boiling water, flex your biceps, and in 30 seconds you’ll have cafe-quality espresso. The design is lovely, and it’s fun to challenge yourself to apply pressure smoothly and consistently (if you’re into that sort of thing).
The Peak Water Filter Jug I use the Peak everyday at home, and it’s revolutionary: the Peak allows me to adjust the amount of ion exchange to target whatever water alkalinity level I prefer for coffee brewing. Given that my tap water at home is quite hard, the Peak has been a godsend and has saved me a bundle on bottled water.
The Decent Espresso Machine Whether you really, really want to make a loved one happy, you’ve got too much cash burning a hole in your pocket, or you just want your significant other to make you extraordinary coffee every morning, the Decent Espresso Machine is the splurge gift of the year. The DE1 pulls beautiful espresso and is easily the world’s most versatile machine. Try the Blooming Espresso, the Allongé, or create your own custom flow and pressure profiles. For the uber-geek in your life, the real-time flow, pressure, and temperature graphs are fascinating to watch while pulling shots. This machine has truly revolutionized espresso, and now it even makes consistent, extraordinary filter coffee.
Call me biased, but I am very happy with my new roasting book. It’s the book I’ve always wanted to write: detailed, prescriptive, and data-driven. I developed the roasting system in the book over many years of offering seminars and consulting for some of the world’s top roasters. Whether one is looking to roast more consistently, manage RORs better, or just avoid ROR crashes, this is the right book. If you have a roasting enthusiast in your life, this would make a great gift.
I’m pleased to announce my newest all-levels online roasting class this November 7.
The class will be broadcast through a private Facebook group. All ticket holders will have access to the class video and discussion forum for one month after the class airs. *It is not necessary to view the class as it airs live.*
Many students of previous online classes have said the month-long discussion forum improved their roasting more than any other class or resource ever had.
During the class we will discuss the samples and their curves from the upcoming Roast Defect Kit. If you would like to receive the Roast Defect Kit in the mail to cup along with us at home, the kit will cost an additional $50 USD plus shipping. The coffee in the new kit is an incredible 88.5-point organic Ethiopian honey setami (a variety new to me!). The RDK is a great educational tool to share with your coworkers or staff!
DATE & TIME: Sat, November 7, 2020 (1:00PM-4:00PM US Pacific Standard Time)
LOCATION: This class is online only.
INCLUDES: Three hours of lecture and Q&A plus one month of online coaching
• Cupping and curve discussion of the "Roast Defect Kit" featuring good, baked, and underdeveloped roasts. • Methods to create consistent, repeatable ROR curves • Advanced methods to prevent ROR crashes and flicks • How to modify roasting machines for better performance. • Pro tips to get the most out of Cropster and other roasting software. • How to adapt strategies to different types of machines. • Analysis of numerous roast curves.
All ticket holders will also have access to a discussion forum on the private Facebook group for one month. I will field questions and discuss students’ curves every day on the forum. The forum will provide a safe, friendly space for a high-level discussion about roasting. This is the same service I offer private consulting clients, at a steeply discounted rate, and in a fun format.
The course is appropriate for roasters of all levels. Although I am calling it an “all levels” class, this course will touch on methods more advanced and practical than anything in the level-three SCA roasting course (those classes are very basic). I guarantee your satisfaction.
Managing astringency in coffee brewing
Oct 08, 2020
I’ve frequently written about astringency on Instagram and Jonathan Gagné, author of the forthcoming book The Physics of Filter Coffee, wrote an excellent blog post about the science of astringency. Here I’d like to offer a practical guide to finding and fixing astringency in brewed coffee.
What causes astringency in coffee?
Large molecules called polyphenols, in particular chlorogenic acids (CGAs) and tannins, are the likely, primary sources of astringency in brewed coffee. Being larger molecules, polyphenols tend to extract less readily than most other coffee solubles, though CGAs seem to extract more readily than tannins do. (It has not been scientifically proven that CGAs extract more readily than tannins do, but it seems probable.) It’s likely the majority of astringent polyphenols found in brewed coffee extract via channeling in percolation brewing. Astringency is much less likely to occur in immersion brewing due to the lack of channeling.
What increases the risk of an astringent brew?
There are several potential sources of increased astringency in brewed coffee:
beans (seeds) from underripe cherry*
underdevelopment in roasting*
channeling during percolation brewing
*Both underripe cherry and underdeveloped roasts tend to yield higher levels of CGAs in the cup. CGAs are both astringent polyphenols and also the most prevalent acids in coffee. Having some CGA is probably important for a delicious cup (though I’m not sure any of us have ever tasted a coffee without any CGAs), but when the CGA level is too high, the coffee becomes noticeably astringent.
How to find and fix the source of astringency
When I find a brew astringent, I go through a series of steps to find and fix the source of the astringency:
If I have previously made a non-astringent, percolation brew of the same roast batch of the coffee in question, it is almost certain that channeling caused the astringency in the more recent brew. In that case, I would brew again with either (hopefully) better technique of a coarser grind setting.
If I cannot rule out channeling (for example, if I don’t trust my brewing method or skill), I will taste the coffee as a cupping. If the cupping is astringent, then channeling was not the cause, or at least not the only cause, of the astringency in the percolation brew.
If both percolation and immersion (cupping) produced astringency, the cause must be due to an underdeveloped roast or underripe cherry.
If some roast batches of the coffee in question are astringent and others aren’t, it is likely that roast development was the cause of the astringency.
If all roast batches of the coffee are astringent when cupped, and you are confident they are not all underdeveloped, then the green was likely from underripe cherry.
How to Choose a Roasting Machine
Apr 09, 2020
If you’re in the market to purchase a coffee roaster, I wrote this book for you. I’ve had the fortune to roast on hundreds of machines throughout my career, and I’d like to help new roasters buy the right machine for their needs. My goal in writing this book isn’t to tell the reader which brand to buy, but to help the reader to understand the important considerations in the decision and to make an educated choice that suits his or her needs.
Most machines from the major brands are capable of roasting a delicious batch of coffee, but some machines have features that make top-quality roasting and replication too difficult, even in skilled hands. Common examples of such features include thin, single-walled drums, slow gas valves, valves with poor resolution at low settings, excessive insulation around the drum, slow or poorly positioned probes, and limited control of roasts after first crack.
When seeking advice about what machine to buy, please ask those who have experience with all of the major brands. Roasters who have used only one or two machines tend to favor those machines and lack perspective about other machines. It should go without saying, but please do not rely on the advice of roasting-machine sales associates, as they are always biased, and often misinformed about the virtues of competing brands.
I do not publicly recommend or critique particular brands in this post, as those opinions are best shared with clients in private. Here, I will discuss what to consider when choosing a roaster. It’s up to readers to infer my opinions of various brands.
Budget
First, consider how much you can afford to spend on a roaster. When calculating your budget, don’t forget to include the cost of necessities such as chimney ductwork, pollution-control equipment, initial green-coffee inventory, QC equipment, a laptop for logging roast data, and various supplies. A budget should also include the costs of installation, permits, and architectural drawings for the permit process.
If you’re a first-time roaster buying a machine with a capacity of between 6 kg–15 kg per batch, I’ve offered current (2020) equipment cost estimates below. Costs will vary country to country; I’m most familiar with the costs in the US, so I’ve referenced those here.
All prices are in USD; I’ve attempted to offer reasonable low and high estimates for each item. If an item’s low estimate is $0, it means the item is optional. I haven’t bothered including optional equipment such as color readers and other QC devices, as they are not critical for a roasting startup.
Key Considerations
With your budget and the above costs in mind, consider how much you can spend on the roasting machine. If you can afford it, please buy a larger roaster than you think you need. I’ve never known a roaster to regret buying a machine that was a bit too large, but I’ve known many roasters who regretted buying machines they quickly outgrew. Once you’ve estimated the startup costs of your roasting operation, prioritize your wants and needs.
1.CapacitY
To choose the proper machine size, it’s important to estimate how much coffee you expect to roast each week over the next two years. Note the weekly amount of coffee you expect to roast two years from today. I recommend buying a machine large enough to roast that quantity of coffee in no more than 25 hours. When performing these calculations, remember that a machine’s real capacity is likely less than its stated capacity, and that beans lose 14%–20% of their weight during roasting. (For reference, third-wave roasts lose approximately 14%, while a Starbucks roast may lose 20% or more.) A machine’s burner capacity—not its drum size—determines how much coffee it can roast well. A reasonable guide is to assume that a quality roast of one kg of green coffee requires 11,500 kj/hr (or, one lb of coffee requires 5,000 btu/hr).*
*This formula does not apply to machines that recirculate hot air back into the roasting chamber. Recirculation machines have higher capacity relative to burner output.
Your roasting-machine salesperson will likely claim that you can roast 15 kg per batch in a 15kg machine. The job of a salesperson is to sell machines, not to help you roast the best-possible coffee, so take any claims lightly. The salesperson may be technically correct, because the drum can surely fit a 15-kg batch, but a full batch may take 15:00–20:00 to roast, which is longer than ideal. If quality roasting is your goal, it’s usually safe to assume you will roast 3–3.5 lf batches per hour at 50%–70% of a machine’s stated capacity. Then deduct the 14%–20% weight lost per batch to calculate how much roasted coffee per hour a machine can produce.
For example, if one were to roast three and a half batches of 7 kg green coffee per hour in a Diedrich IR-12, with an average weight loss of 15%, the machine would produce just under 21 kg of roasted coffee per hour (3.5 * 7 kg * .85 = 20.8 kg). That’s more realistic than assuming the machine will roast 48 kg per hour.
2. Reliability
Some machines are more reliable than others. Machines with fewer parts, fewer high-tech features, and heavier builds tend to be more durable and reliable. Older, simpler roasters, such as the fabled UG-series Probats are examples of rugged, low-tech machines built to last. Of course, all design decisions entail tradeoffs. Some modern technology may lack reliability but make quality roasting easier and more repeatable. Again, ask other users about reliability before buying— I’m sure most roasters would be happy to share their experiences, especially if they have complaints! While roasters are not always objective about their own roast quality, they tend to be somewhat objective about the reliability of their machines.
3. Service
Many brands may not offer service or support in your country. Further, some companies offer poor support once you have paid for your roaster. I won’t publicly discuss which companies, in my experience, neglect their customers, but I implore you to ask other users of a brand about service quality before you put a deposit on a machine. Even if you have a pleasant initial sales experience with a company, that does not guarantee future service quality.
4. User Interface:
This may seem like a trivial consideration, but if you’re going to spend 20–40 hours per week using a roaster, a well-designed user interface is important. The interface isn’t just about convenience and comfort, it can also affect roast quality and repeatability. For example, machines that require you to repeatedly tap an up- or down-button to change the gas setting can be tedious and slow to respond. In comparison, a machine with an analog gas dial or a smart touchscreen is more responsive, makes it easier to replicate curves, and can be a pleasure to operate. Other ease-of-use considerations involve having large, well-positioned digital manometers, timers, and temperature readouts.
5. Aesthetics
You may want to consider aesthetics if you are installing a machine for use in a retail cafe or other public space. A beautifully refurbished vintage machine may make a nicer impression than a budget, modern machine.
6. Machine Configurations
I discussed this topic in detail in The Coffee Roaster’s Companion, but will repeat the basics here. Common architectures include classic-drum roasters, indirectly fired roasters, recirculating roasters, and fluid-bed roasters. Each design has pros and cons.
Classic drum roasters: In these machines a drum rotates above a gas flame, and a fan pulls hot air from the burner through the drum and out of the roaster. Most smaller machines are classic drum roasters. Classic drum roasters get the job done, though many models provide too much conductive heat transfer, due to having a thin single-walled drum or an improper distance between the burner and drum. If too much heat is transferred to the beans via direct contact with the drum, coffee will taste harsher and less delicate. If you choose a classic drum roaster, I suggest you seek a machine with a double-walled drum and a burner with sufficient btu/hr (or kj/hr) for your needs. Compared to other designs, classic drum roasters offer good thermal stability but slower responses to gas changes.
Indirectly heated drum roasters: In these machines the burner chamber is separated from the drum and hot air passes from the burner chamber through the drum. The design allows the drum’s surface to remain cooler because the flame is not in contact with the drum. Indirectly heated roasters are more difficult to control than classic drum roasters, because they require skillful management of airflow, while classic drum roasters rarely require much, if any, airflow adjustment.
Recirculation roasters: These machines recirculate a portion of the roasting exhaust air back through the burner and roasting chamber. Such machines are energy-efficient but often run the risk of imparting smokey or polluted flavors on coffee. To avoid smoke taint, it’s important to heat the recirculated air to a sufficiently high (afterburner-level) temperature before passing it through the drum.
Fluid-bed roasters: These machines rely on a bed of rising hot air to circulate the beans and keep the beans aloft. Fluid-bed roasters eliminate the risk of conductive-heat damage, and are usually capable of developing beans well in short amounts of time. While there is no theoretical downside to fluid-bed roasters, in practice their control systems are usually too simplistic to fulfill the machines’ potential. Given the current, rapid evolution in roast-control and data-logging software, I expect the utility and popularity of fluid-bed roasters to grow rapidly in the near future.
7. Features
None of the features listed below are necessary to roast a good batch of coffee, but each may contribute to improved roast quality or repeatability.
Double drum (applies only to classic drum roasters) and powerful burner:The foundation of a good classic drum roaster is its burner and drum. As noted previously, burner output determines a machine’s true capacity. Double drums allow for faster and hotter roasting with less risk of tipping or scorching. Make drum quality and burner output your first two concerns when choosing a classic drum roaster. You can easily replace or upgrade fans, valves, ducts, etc, but you cannot easily replace a drum, and upgrading a burner can be expensive.
Variable-speed-drive (VSD) fan: As long as your roaster’s fan provides a reasonable amount of draw, you don’t need a variable-speed fan to produce good roasts. But without a VSD fan, it’s impossible to maintain consistent airflow levels day to day. The combination of a digital air-pressure manometer and a VSD fan is essential for expert-level roast repeatability.
Air manometer (aka drum-pressure manometer): A manometer in the duct between the roasting drum and exhaust fan is a relatively new, worthwhile addition to a roaster. The manometer reads pressure, not flow, but that pressure reading correlates with airflow. Using the same fan setting every day does not ensure consistent roasting because airflow may vary day to day with the weather and other factors. Having an air-pressure manometer helps one know how to adjust the fan to provide consistent airflow every batch. (Note: directly measuring airflow requires installing probes in the exhaust duct, but the probes get dirty too quickly during roasting to work effectively. Using an air-pressure manometer is the best current option to monitor and maintain consistent airflow batch to batch. However, the relationship between pressure and flow will shift slowly as the ducts get dirty, so frequent chimney cleaning is critical.)
High-resolution gas manometer: Most roasting machines come with small, cheap analog manometers that offer imprecise gas-pressure measurements. I recommend replacing your stock analog manometer with a high-resolution digital manometer. Analog manometers may be aesthetically pleasing, but they make discernment of precise readings too difficult.
Proper probes and probe locations: To be a great roaster by today’s standards, one needs better green, lighter roasts, quality data collection, precise controls, and software to track and analyze the data. To ensure adequate data collection, insist on having a bean probe and an environmental probe, each with diameters of 2.5 mm– 4 mm. An inlet-temperature probe is helpful but not critical.
The optimal bean probe location in most machines is as follows:
The probe’s tip should be 3–5 cm from the inside of the machine’s faceplate.
The probe’s tip should be 3–5 cm from the inner drum edge. (2 cm is ok for machines with capacity of 1 kg or less.)
The probe tip should be in the heart of the bean pile, even when roasting very small batches. If the probe is too high in the drum or too close to the center axle, it may not be immersed in the bean pile of very small batches. Proper probe location should provide quality data for batches as small as 20% capacity.
Paying for a machine: Manufacturers typically require the buyer to deposit 50% of the machine’s price upon ordering, with the balance due upon shipment of the machine. The problem with such arrangements is that once a manufacturer has your deposit, he or she may lose motivation to deliver your machine on time. Salespeople routinely promise a machine in three months, secure a deposit, and then ship the machine six to nine months later, claiming unavoidable delays. The buyer is helpless as he or she pays rent on an empty roastery and loses money waiting for the machine to arrive. I have seen such delays happen on fully half of my clients’ orders. I strongly suggest insisting on a sales-contract clause guaranteeing delivery by a certain date, with a penalty against the manufacturer for late delivery.
Given the number of considerations listed above, how should one prioritize them when purchasing a machine? Here is how I would prioritize the list:
Ensure a brand’s machines are reliable.
Seek out features that assist in precision roasting.
Find a company that offers prompt, reliable service, with service representatives based in your country.
Cost (relative to burner output and features)
Other considerations discussed above, such as installing a better probe or manometer can often be arranged with the manufacturer or added after you receive a machine.
The Bottom Line
When choosing a roaster, I suggest you determine your budget, make a prioritized list of your needs and wants, and ask other roasters about their experiences with various machines. Trust others’ opinions about machine reliability and service, but be skeptical of their opinions about roast quality unless they have had extensive experience on numerous models of roasters. Ignore subjective information from salespeople. When possible, arrange with the manufacturer or another roasting company to spend a few hours working on a model of machine before committing to its purchase.
Notes about accessories:
Floor scale: Please choose a sturdy floor scale with a resolution of no more than 0.005 kg (0.01 lbs) and a maximum capacity greater than the weight of your largest batch plus the bucket in which you will weigh that batch. You may want a scale with even larger capacity if you plan on blending together full batches. The scale’s resolution must be precise enough to provide useful weight-loss calculations.
Timer: Your software or roaster’s control panel probably tracks roast time, so you shouldn’t need a separate timer. If you do need one, make sure it is easy to read from a distance.
Spotlight: I recommend mounting a lamp with a full-spectrum bulb just above the bean trier. While I recommend using the trier sparingly, it should be well-lit for those rare times you use it.
Fire-suppression: I recommend hard-plumbing a water line into the roasting-machine faceplate and chaff collector. The water line should include a spray head with an easy-to-access valve. This is probably the best insurance you can have against a roaster fire.
Small accessories list:
Please consider this list a starting point; it is not comprehensive.
Large scoop for green coffee
Large scoop for roasted coffee
Buckets for green coffee
Separate, larger buckets for roasted coffee
Bucket labels and markers
Tables or counters for weighing, bagging, and boxing
Empty bags and boxes
Heat sealer
Wet/dry vacuum for cleaning chaff collector
Brush for chimney cleaning
Rags for wiping oil from buckets and cooling bin
Knife and/or scissors for cutting open green-coffee bags
Commercial dishwasher (if you can afford it)
Cupping supplies
Packing tape
Label printer
High-temperature, food-grade silicone (for resealing pipes after cleaning)
Sometimes the most fundamental and important messages seem to get lost in the details. Some of what is said online and otherwise about roasting, and about what I have said about roasting, is mistaken. I’d love to set the record straight on the fundamentals and my beliefs, and there’s no better time to do it than just before my upcoming beginners’ online roasting class.
Roast Time There is no one “correct” duration for a roast. However, depending on your machine, gas pressure, and batch size, there is a reasonable range of roast times. For example, one can’t say “an eight-minute roast is too fast” without knowing the context. Eight minutes is not too fast when roasting 3kg in a Probat P12, but definitely too fast when roasting 12kg in a P12. It’s all in the context.
I don’t recommend a specific roast duration; instead, I always teach that optimal roast duration is dependent on the ratio of batch size to burner output.
Roast Color
I’ve never told a client how light or dark to roast: to me, that is a personal and business decision. While i’d love to see most roasters roast lighter, and while I personally choose to roast and consume extremely light roasts, light roasting can be a poor business decision for many. I also believe roasters should roast only as light as they have the skill to do successfully; if you often underdevelop coffee, then I recommend roasting a little darker until you have figured out a system to improve development of lighter roasts.
The Best Roasting Machines
I do not recommend any particular brands, at least not publicly. I’ve said kind words publicly about a couple of brands, but that was not a recommendation to buy their machines. If I were to publicly name my top three roasting machines, everyone reading this would be very surprised by at least two of them. When clients ask me what machine to buy, I explain the pros and cons of various machines, and ask them to talk about their preferred roast style and budget. We also consider factors such as which brands offer service in the client’s country. There is no machine that is ideal for everyone. While it’s perfectly sensible for Tim Wendelboe to roast on a Loring, a machine well-suited to light roasting, it’s equally sensible for a second-wave chain to choose a classic-drum roaster such as a Probat. One should consider budget, service, roast style, ease of use, preferred degree of automation, reliability, and several other factors when choosing a machine.
Data Collection
It would be inadvisable to look at a curve I post online and try to copy the numbers using your roasting machine. I may hit first crack at 375f (190c) and drop a batch at 405f (207c) but on your machine the equivalent numbers may be 10f (5c) higher (for example), depending on our relative probe calibrations and the environmental temperatures at those moments in the roasts (ET readings affect BT readings.)
Having a reasonably good probe (2.5mm—3mm diameter, ungrounded is my preference) in a good location, using Cropster or Artisan, and learning to read curves is critical. Prior to data-logging software, specialty roasters as a group made little progress for decades. After data logging became popular, roasters’ learning curves went vertical. Please do not assume that your machine’s manufacturer has set you up for proper data collection. If they are not offering a 3mm (ish) probe and an ET probe, both well located, at the least, please talk to them about it. I find many manufacturers to not be very interested in data collection and presentation, but customer demand for better data collection has altered their decisions significantly over the past five years.
Baked Roasts
It’s taken years, but I’ve won over many roasters to the understanding that baked roasts are caused by hard ROR crashes, not by slow roasting. Some roasters intentionally bake coffee to decrease acidity, though I recommend other methods to accomplish that. Baked coffee is generally less sweet, more hollow-seeming, and often has hints of straw and flatter acidity.
DTR
Sometimes I wish I had never invented the concept of Development Time Ratio. Despite it being just one concept in a 100-page book, 99% of comments about the book have focused on DTR. DTR is often misunderstood, so let’s address that: the book wasn’t written for only those who roast on very lightly (that I am fond of light roasts); it was written for all of the world’s roasters. If you think 15% is the perfect DTR for your middle-of-first-crack drops, please know that you are in the 1% of the world’s very light roasters. It may be appropriate for you, but I would have done a disservice had I written a book full of advice that excludes 99% of the world’s roasters.
DTR is useful as a QC tool, as a target, and as an indicator of a balanced roast curve. However, if your ROR is crashing and flicking all over the place, your DTR doesn’t matter. DTR is also not a good reason to drop a batch; please drop batches based on color or bean temperature. STEP ONE in roasting is to control and smooth your RORs. Step two is to worry about DTR and everything else.
SMOOTH RORs
I’ve saved the most important issue for last: First, please trust that 99% of roasters’ RORs are not smooth enough to eliminate all roast defects. I know this because for some reason people ping me weekly on Instagram showing me their “smooth” curves, but less than 1% of those curves have in fact been smooth. (PS Please don’t DM me on IG with your curves, my inbox is a disaster :0. Thanks.)
It’s very difficult to master smooth RORs. So difficult, that when roasters tell me they don’t believe smooth RORs are good, I know they haven’t actually mastered—and I do mean mastered—smooth RORs. I know this because I’ve consulted for about 600 roasters and 99% of them have been happier with their roasting once their RORs became pretty smooth. Only 10% of those clients are what I would call ‘masters’ of smooth RORs. Mastery takes time and practice, like it does in any pursuit. By definition, it cannot be a formula or something you attain in a few weeks or months.
Many of these comments may be controversial to some people. That’s great news— disagreement leads to our mutual learning, but only if there's engagement. I openly invite contrary opinions and comments so we can talk about it and find some common ground. Thank you.
Beginners' Online Roasting Class!
Mar 29, 2020
April 18— May 17
I’m pleased to announce my first online roasting class for beginners, April 18. This class is appropriate for anyone curious about roasting, with up to two years’ experience.
The class will include:
Anatomy of a roasting machine
How to tune a roasting machine
How to choose batch size, charge temperature, air, and gas settings.
Basic management of roast curves
Advice on buying and storing green coffee
Fundamentals of data collection
Included in the class will be membership to a month-long private Facebook coaching group. Members will be welcome to ask questions, post roast curves, and discuss other’s questions and curves as well. I’ve found that such “group consulting” is not only extremely effective, but also a lot of fun. I look forward to seeing you there.
MEMBERS WILL HAVE ACCESS TO THE CLASS VIDEO FOR ONE MONTH, TO VIEW AS MANY TIMES AS THEY WOULD LIKE.
NB: It’s not necessary to tune in to the class live, but it’s helpful if you would like to send questions during class.
Welcome to The Coffee Innovation Summit
Feb 05, 2020
our venue in Melbourne
LATE EDIT: THE COFFEE INNOVATION SUMMIT HAS BEEN CANCELLED; MATT AND I WILL INSTEAD USE THE SPACE WE RENTED IN PORTLAND TO HOST A FEW INFORMAL EVENTS. MORE ON THAT IN A NEWER POST. WE APOLOGIZE FOR ANY INCONVENIENCE.
I’m excited to announce The Coffee Innovation Summit. Matt Perger and I will be organizing two one-day events, one in Portland on April 23 and the other in Melbourne on May 3, coinciding with SCA Expo and MICE, respectively.
The Coffee Innovation Summit will explore the cutting edge of specialty coffee. The program will include live tastings alongside presentations of innovative ideas by industry experts. Attendees will have the chance to experience our speakers’ innovations firsthand.
Throughout the events, our team of top-tier, paid baristas will serve numerous high-quality coffees, demonstrating industry best practices. All of the coffee we serve will be chosen and roasted for the event, and brewed on cutting-edge equipment using custom-made water. We plan to not only offer delicious, memorable coffee, but also carefully curated, interesting tasting flights to complement our presentations.
We are still confirming our full roster of speakers, but so far, presenters and topics in Portland include:
Optical sorting of green coffee for specialty production - Jon Allen, Onyx Coffee Lab
Controlled fermentation of coffee using wine yeasts - Lucia Solis, Luxia
The next generation of espresso grinds distribution - Matt Perger
Ultraviolet fluorescence of green coffee to detect defects - Christopher Feran, Phoenix Coffee
Roast defects: how to detect and prevent them - Scott Rao
Please click HERE to buy tickets for the Portland event.
Please click HERE to buy tickets for the Melbourne event.
Topics and speakers in Melbourne so far will include:
Optical sorting of green coffee for specialty production - Jon Allen, Onyx Coffee Lab
Recent green processing experimentation - Aida Batlle
The next generation of espresso grinds distribution - Matt Perger
Roast defects: how to detect and prevent them - Scott Rao
our venue in Portland
What are the best dose and brewing ratio?
Feb 05, 2020
How should you determine the optimal dose and brewing ratio for espresso or filter? Ongoing conversations I’ve been having with Jonathan Gagné and the recently published piece of espresso research by Chris Hendon et al, have been keeping this issue top of mind. I hope this post will provide readers with food for thought when making brewing decisions.
Rather than always relying on standard, popular ratios (eg 2:1 for espresso, 17:1 for filter), I recommend baristas consider a few factors when deciding on a ratio for a brewing method.
Desired TDS and Extraction Yield: each particular combination of EY and TDS can only be achieved by a unique brewing ratio. If for some reason you desire a specific TDS and EY combination, such as 1.4% TDS and 22% EY, there is only one ratio that can produce that pair of numbers. This also means that you may want to use different brewing ratios with different grinders. I recently brewed the same coffee as a v60 on my DE1 using two different grinders; one grinder achieved 24.5% EY/ 1.6 TDS. The other grinder could achieve only 21% EY/ 1.4 TDS. If my goal is to always have a TDS of 1.4 at the highest possible EY, I would consider using a higher brewing ratio with the first grinder.
Channeling: In percolation methods, it’s important to use a ratio that won’t lead to noticeable channeling or astringency. In espresso brewing, better puck prep will allow a barista to use a higher ratio (say, 3:1 as opposed to 2:1) without channeling. If you have poor puck prep, or if your grinder produces a lot of clumps, you may want to consider decreasing your brewing ratio to avoid astringency due to channels. In drip brewing, the more evenly you spray or pour the water over the coffee bed, the less channeling will occur. The more evenly the water extracts from the coffee bed, the higher the ratio (within reason) you can use without channeling.
Bed Depth: Whether pulling an espresso, brewing in a v60 or using a Fetco, each basket you use has an optimal range of bed depths. Batch brew bed depth should typically be 3cm—5cm. A device such as a v60 generally brews best in a range of 15g—22g of coffee (5cm—6 cm.) Coffees of extremely high or low density may require small adjustments in dose to maximize extraction. Note that many cafes that serve two-liter batch brews use baskets designed for larger brews. If you brew two-liter batches, the smallest-diameter baskets available for your batch brewer may help to increase the bed depth of your doses into the recommended range.
Flavor defects If you’re brewing a defective or poorly roasted coffee, you may improve flavor and mask some of flavor defects by lowering your ratio and extraction level. Intentionally underextracting charred, baked, or underdeveloped coffee can sometimes make it more palatable.
Beverage Sizes When planning a dose and ratio for espresso, it’s important to consider the sizes of your milk drinks, and how much total dissolved solids your shots will contain. For example, a 15g dose at 22% extraction would provide 3.3g of dissolved solids, while a 22g dose at a more modest 22% would provide 4.84g solids. While the 15g dose may be appropriate for a cappuccino or a cortado, its 3.3g of dissolved solids would nearly disappear in a 12oz latte. The 22g shot may be just right (for some) in the latte. Some cafes choose to use larger (20—22g) doses and to “split” the shots so they can use a single shot for straight espresso and very small milk drinks and two shots for larger milk drinks.
Do you have some thoughts on other factors to consider when determining a dose and brewing ratio? Please share your thoughts in the comments section. Thanks for reading.
Australian and American coffee bars: Their differences, and what they can learn from each other
Dec 22, 2019
There are two significant differences in how third-wave baristas serve coffee in the US and Australia. I believe if baristas in each country adopt the other’s practices, it would improve labor efficiency and speed of service in both countries.
Batch brew makes up perhaps 40% of coffee orders in the US, but less than 5% in Australia.
Most Australian baristas “split shots,” while few Americans do.
I believe Australian and American cafes could benefit from adopting some of each other’s practices.
Batch Brew
The obvious benefit of batch brewing is it requires much less time and labor to serve. Given the high cost of labor in Australia, many cafe owners have expressed a desire for customers to embrace batch brew. Unfortunately, customer acceptance has been slower than many in the Australian coffee industry would like. While I’m not an expert on the Australian market, I’d like to make a few suggestions to help customers warm to batch brew:
Do it well. Unfortunately, the popular Aussie choice to use a Moccamaster in a cafe is not good enough. Moccamasters do a poor job of achieving even extractions, and their brewer/carafe design causes excessive heat loss during brewing. That heat loss, compounded by suboptimal brewing-water temperature, greatly accelerates the aging rate of the brewed coffee. (If you must use a Moccamaster, please use the commercial version with the round spray head and find a way to prevent heat loss from the carafe during brewing.)
Don’t serve old coffee. Most Australian third-wave cafes that serve batch brew hold the brewed coffee too long (as do most Americans). Serving two-hour old batch brew is not going to win converts. I feel for Aussie cafes here: batch-brew machines are generally designed to brew at least two liters at a time, but the cafes don’t serve enough batch brew to brew that much coffee without having to pour most of it down the drain. (The good news is I believe in the next year there will be at least two new batch brewers designed to produce excellent batches smaller than two liters.)
Talk it up. Explain to customers that batch brews offer great extraction quality. Give them free samples while they wait in line, especially to those who order long blacks and americanos. Offer an interesting coffee exclusively on batch brew. Hold events featuring your best coffees on batch brew. Familiarity is the key to acceptance.
Splitting Shots
Italian espresso developed around small doses of 7-ish grams and beverages no larger than 150ml (5 ounces). In the 90s many specialty-coffee markets adopted larger drinks sizes, which require significantly larger doses. For example, if you’re a Starbucks barista serving 20oz (600ml) lattes, it would be reasonable to use doses of 20g or more. (Note: I do not know what dose size Starbucks uses.)
Australians have never warmed to the massive beverage sizes common in North America. Aussie cafes generally serve Italian-sized beverages with the occasional 250—350 ml (8—12oz) caffe latte on the menu. Serving smaller-sized drinks has allowed many Australian coffee bars to split shots, or pull two shots from one portafilter. In a country where few customers order batch brew and almost every coffee is espresso-based, splitting shots is critical to enhance efficiency and control labor costs. Of course, a few third-wave American cafes split shots, and a few Australians don’t, but they are exceptions to the rule.
Specialty shops in the US used to serve a variety of larger beverages, using massive espresso doses. However, as US third-wave shops have gradually adopted the smaller sizes common in Australia, American baristas now have a chance to improve efficiency by splitting shots, and, I believe, improve many beverages. I hope some US third-wave shops will consider splitting shots; as beverages have shrunk and extractions have increased, split shots have become more appropriate than they used to be. Half of a 20-gram dose is plenty for a straight shot of espresso, a 5-oz (150ml) cappuccino, a macchiato, and most hipster-sized drinks (cortados and gibraltars). The full 20g dose is plenty for a 12-oz latte, if a cafe chooses to serve one beverage that large.
The Upshot
While this post isn’t revelatory to anyone who has ordered coffee around Australian and the US, it does bring up some potential ways each country can benefit from the other’s practices. The part of the American market that offers smaller beverages is ready to split shots, which will cut coffee costs and improve labor efficiency and speed of service. Australian baristas have a chance to introduce their customers to batch brew at its best, which would greatly cut labor costs if widely adopted. But winning customers over to batch brew may require best practices and greater familiarity: Brew small batches in quality brewers. Brew into enclosed, appropriately sized thermal carafes with “brew-through” lids to conserve heat. Never brew more than one coffee at a time or two liters per batch. Ditch brewed coffee before it tastes sour and bitter. Feature batch brew at tasting events and demonstrations. Gently familiarize customers with batch brew.
ONLINE ALL-LEVELS ROASTING CLASS + FORUM
Nov 23, 2019
I’m pleased to announce I will offer an online roasting course on January 4th, 2020. The class will be broadcast through a private Facebook group. All ticket holders will have access to the class video and discussion forum for one month after the class airs. Many students of previous online classes have said the month-long discussion forum improved their roasting more than any other class or resource.
Please note that it is not necessary to view the class when it airs live.
All ticket holders will have access to the class and forum for one month. During that month you can view the class as many times as you would like.
Please join us online, or if you’re in Southern California, we’d love to see you in person. Live seating will be limited, so claim your seat ASAP. The class will be held at Common Room Roasters in Costa Mesa from 1pm—4pm.
All ticket holders, live and virtual, will have access to the class video for one month through Facebook.
**ONLINE CLASS ACCESS WILL BE FROM JANUARY 4 -- FEBRUARY 3, 2020**
All ticket holders will also have access to a discussion forum on the private Facebook group for one month. I will field questions and comment on students’ curves every day on the forum. The forum will provide a safe, friendly space for a high-level discussion about roasting, something difficult to find anywhere else. Students of past online courses have found the forum helpful for solidifying the class lessons, have enjoyed the community feeling, and many have shared their roast-curve progress on the forum.
The course will be appropriate for roasters of all levels. Although I am calling it an “all levels” class, this course will touch on methods more advanced than anything in the level-three SCA roasting course (even their “advanced” classes are basic), and I guarantee your satisfaction.
The class will include:
Three hours of lecture and Q&A
Cupping and curve analysis of the "Roast Defect Kit" featuring good, baked, and underdeveloped roasts.
Methods to manage ROR curves
Advanced methods to prevent ROR crashes and flicks
How to modify roasting machines for better performance.
Pro tips to get the most out of Cropster and other roasting software.
How to adapt various strategies to different types of machines.
Online tickets are $125 USD, live tickets are $175. During the class we will cup samples from the upcoming Roast Defect Kit. If you buy a virtual ticket and would like to receive the Roast Defect Kit in the mail to cup along with us at home, the kit will cost an additional $50 USD (making online and live tickets the same price.) The RDK is a great educational tool to share with your coworkers or staff. (Note: we are sorry but cannot ship the RDK to South Africa, China, Russia, Greece, or Brazil.)
The vast majority of machines I’ve worked on in my consulting career have needed what I call “tuning.” For example, just this past month, a client with a new Probat had far less airflow than he needed, due to his chimney configuration. Two experienced clients were operating with less than half of their respective machines’ optimal gas pressures. Several clients were operating machines with suboptimal drum RPMs or airflow levels. One client had both inadequate gas pressure and inadequate airflow, caused by an air leak at the loading funnel. Several roasters were using excessive software smoothing or slow thermocouples.
Proper gas pressure, drum RPM, airflow level, probe size and location, and software settings are all necessary before one can roast great coffee with impressive consistency. My experience implies that most roasters reading this post likely have tuning problems of which they are not aware. All of the issues below can be remedied quickly or cheaply. Fixing any of them will provide an excellent return on the invested time or money.
Gas Pressure
Every gas burner is designed to work safely and efficiently in some range of gas pressures. For example, your machine’s manufacturer may recommend a range of 3–5 kpa (12–20 inches of water column). The recommended range should be listed on a badge on the side of your roaster or on the manufacturer’s website. What almost no one tells roasters is that pressure at the top of the recommended range offers a lot more power and efficiency than pressure at the bottom of the range. Suboptimal gas pressure forces many roasters to roast smaller or slower batches. I’ve seen increases in gas pressure lead to 50% increases kg per hour of roasted coffee.
Drum RPM
Even if your machine is brand new and the manufacturer installed it for you, check its drum RPM. A few major manufacturers deliver machines of a given model with widely varying RPMs (often a difference of 20 RPM machine to machine). Some whom I’ve asked to fix it for my client have claimed “it doesn’t matter” (one of those same manufacturers has told me that ROR crashes don’t matter, so be careful where you get your roasting advice!) Please count your drum RPM over the course of one minute. If your machine’s RPM are either too high or too low, it will cause more conductive heat damage and harsher coffee. Very low RPM can also contribute to ROR crashes.
My RPM recommendations are in the chart below. If you have a 12kg roaster with, say, 35 RPM (a frequent problem from one manufacturer), you will not be able to avoid ROR crashes and excessive conductive heat transfer. You may be satisfied with roasts from a low-RPM machine, but the coffee will be noticeably better when you adjust the RPM to the proper range.
Airflow
There are many causes of improper airflow levels in roasting: air leaks, such as loading hoppers that don’t seal well, fans spinning in the wrong direction (more common than you would think), chimneys that are too tall or have too many 90-degree angles, or simply roasters adjusting fans and dampers improperly. If your roasting-exhaust and cooling-air chimneys merge before passing through the roof it may cause back pressure in the roasting drum and shifts in roasting airflow depending on whether the cooling fan is on.
If your RORs decline with a relatively constant slope, your ET curve should stop rising somewhere just before or around the beginning of first crack (there are too many factors to be more specific here). If your ET peaks more than two minutes before first crack begins, you probably have too much airflow. If your ET curve rises all the way through the end of a roast, you are probably using too little airflow. And of course, if lots of smoke or chaff pours out of the drum when you drop a light or medium roast, the airflow is probably set too low.
Probes and Software
This probe is slow enough to make the data almost worthless.
Quality data collection and presentation are essential to quality, consistent roasting. If the turning points of your roasts are routinely later than 1:30, your probe is probably too slow. If your RORs look very noisy when viewed in the 15-second averaging interval in Cropster RI3 (or the 15s delta span in Artisan), you may have excessive noise in your system. (I covered this issue more thoroughly in my July 4, 2019 post.) If your RORs are smooth, rather than jagged, curves, your smoothing settings are too generous.
Please don’t assume that if you like the way your coffee tastes or your machine is new that it doesn’t need tuning. Few of the roasters I’ve worked with whose machines needed tuning knew there was a problem, but all were happier with their roasts after we tuned their machines.
Q&A COFFEE PODCAST, EPISODE 2: BREWING
Aug 01, 2019
As of today’s podcast, I ‘ve begun separating the podcasts by theme: brewing, roasting, coffee & health, etc. My hope is to help listeners decide which episodes may interest them most. Today I fielded questions with Vassily about brewing, with a few coffee-business questions in the mix as well.
EPISODE TWO (also available on iTunes):
EPISODE QUESTIONS & TIMES
Mirko Thamm (1:10)
1: concerning the CO2 level of the beans. Is it better to degas after grinding (30-45min) or to grind and brew directly after grinding. Which way will get better (sweeter or more consistent) results?
2: Sieving the grind. I sieved my grind and if I used just a small range of particles (like 400-500 micrometer) the coffee was not as complex as the whole range. Should we sieve the course particles (bigger than 500microns), the fines or just a small range? Thanks
From Jonathan Mitchell (5:20)
#1 Business - I have a few potential office/law firm clients that want to become a wholesale partner but they are reluctant to keep a grinder on hand. They want me to pre-grind the coffee. I am already a little hesitant to have my coffee represented in this area but it feels like an untapped arena and a decent source of revenue. What are your thoughts?
#2 Any tips on partnering/raising money for future expansion? I am so scared of losing ownership, as I never want to compromise profit sharing with my employees, but I am also scared to dip into my personal savings for a new shop.
Benjamin Byrd , Due South Coffee Roasters (09:55)
I have a Breville precision brewer on the way and I was wondering if you had any tips on programming it for the best results, or if the batch brew rules blog was directly applicable to it. Thank you for your time and for all you do to save the industry from underdevelopment!
Ghazi Almoayed (12:30)
Hey Scott
I have 2 questions for you about espresso brewing:
1. What are you thoughts on lowering pressure to 5 or 6 bar? Is this beneficial for better extractions + consistency regardless of roast level
2. For lighter roasts I have heard about extracting 1:3 . So 18g in with 54g out. Is this only possible with an EK grinder or can a Baratza Forte still pull this off? What sort of timings should one aim for when attempting those ratios ?
Nuno Cristiano de Sousa (19:48)
Hi Scott!
First of all, thanks for taking the time to answer questions of the community - How do you scale up your filter recipes?
I can make my extractions pretty aromatic and balanced with a 2 pours recipe, comandante 25clicks, pouring at an average 2.5ml/sec (measured in acaia). If the flow rate is higher, the total time is lower, and that messes up the extraction.
However when I tried to scale up to 500ml/17oz, i changed the grind to 28 clicks, kept flow rate, and the average extraction time raised to 3:30.
Q&A COFFEE PODCAST WITH SCOTT RAO
Jul 14, 2019
Photo credit: Norman Mazel (@normanito)
I get an endless stream of unsolicited coffee questions in my inbox. In the past I’ve tried to reply to every such email and instagram message, but it became a bit too time consuming. I decided recently to try to answer some of these questions in podcast format. The podcast will air monthly(ish) and contain a mix of beginner and advanced questions about both brewing and roasting. Most podcasts will include a guest with whom I’ll discuss the questions and answers. I hope to share most episodes with coffee-pro friends who will be able to answer some of the questions outside of my wheelhouse, such as those about green processing.
This first episode is all about feedback. The podcast is 29 minutes. Is that too long? Too short? It’s a mix of brewing and roasting questions.. Should we have separated the roasting and brewing segments for those who are interested in only one or the other? I’m new at this, so please let me know what I can do better. Thanks
The podcast, Episode one (also available on iTunes):
Below is a link discussed in the podcast, the questions, and the time at which each question was addressed, in case you would like to skip around.
As far back as I can remember, I’ve been told to very quickly wiggle and rinse the portafilter under a running grouphead before drying and filling the basket. A friend recently told me that not only is this unnecessary, but actually flat out wrong.
I’ve been searching online for sources and test results to prove one method or the other, but to little result. Does simply wiping remove enough of the fines and coffee oils that might have baked into a portafilter between shots? If I rinse and flush after I pull a shot, is it unnecessary to do so before? Will the water from the grouphead cool quickly enough to cool the portafilter? If only wiping is the more reliable method, how many shots can you pull with wiping in between before rinsing is completely necessary
2. From GIORGOS PAPANTONIOU (6:00)
During a pourover, which is a preferred slurry temperature in your opinion?
You see, I recently bought a water boiler in order to fill my kettle for handbrews and to my surprise the water temperature was really low, because of the heat loss during transfer, and led to really low slurry temperatures as well. I didn't see that coming since so many coffee shops around the world are working that way. Filling the pourover kettle from a hot water source. It was really hard for me to accept that so many people are brewing coffee with hardly 90 degrees Celsius in their water kettle. And I think it's important to mention the slurry temperature and not the starting water temperature because depending on the brewing method, the first one may vary significantly.
3. From Meshal Alshehri (10:00)
I would like to know more about your methodology of developing a batch brew coffee recipe using Fetco or any other brand.
Trial and Error is costly especially when changing coffee types.
4. From Tarik (13:45)
Hi Scott, how do we measure tds for espresso in the refractometer without vst syringe filters? Thanks
5.FromGhazi Almoayed (18:58)
When building your own water for espresso , is the general rule if the water does not work on a filter brew that means it would also not work on espresso ? Can this be used as a guide to choosing a water for a given coffee ?
I have not had good results with the Barista Hustle recipe water on Kenyans , has this been something you noticed ? Might be to do with the fact that Kenyans need more buffer ?
6. From Jason Richter (23:11)
Hey Scott, here are two questions I have right now.
1. How do I make sure I'm choosing the right charge temp for an individual bean?
2. How does ambient air temperature affect the flavors you get in the cup.
Thanks to everyone who submitted questions, and thanks to everyone who listens and leaves feedback. I look forward to hearing from you.
Idle noise, ROR intervals, and analyzing roast curves
Recently, Marko Luther of Artisan published a fascinating blog post “On Idle Noise.” Marko’s post discussed how to diagnose and fix “idle noise,” or background noise present in one’s data collection and processing when using Artisan. Marko offered a simple test of noise by data logging bean-probe readings with a roasting machine off and with its motor on (with no beans in the machine). I’m pleased to have inspired part of Marko’s post and to also recognize him here for his brilliant work. Please read the post and do his idle-noise test on your machine .
Marko’s post is a little complicated, so I’d like to show a few simple curves illustrating various levels of bean-data noise and software smoothing of the noise. It is a little easier to see excessive noise in Artisan than in Cropster, so I will focus on Artisan curves here.
A few definitions before we begin: in each of the next few curves, there is a box on the left containing various settings. All of these curves had the following settings:
Sampling interval:1. Sampling interval is the amount of time between each point of data collection from the probe. For instance, a sampling interval of three seconds means that the software asks for data from the probe every third second. Here I have set the sampling interval to one second; Marko recommends three seconds. I used 1s to match the default sampling interval of Cropster, in order to help Cropster users better relate to these curves .
Smooth Curves/ Smooth Deltas: 0 I have set these to 0 in order to not artificially smooth the data. (Other than via the delta span.)
Delta Span: 1s or 15s Each curve is shown with the shortest (1s) and longest (15s) delta spans Artisan offers. The delta span is the time interval over which the ROR is calculated. In other words, any given ROR reading is the average of , respectively, the last one second or fifteen seconds of data. Longer delta spans make curves look smoother. Delta span is what Cropster calls ROR Interval.
Here is an ROR curve derived from very noisy data, with the delta span set to 1s and 15s. Note the intense vertical spikes in the 1s delta-span view; they are telltale signs of data noise.
Delta span of 1s: Note the spikes in the blue (ROR) curve. This is very noisy data.
Side note: you will rarely, if ever, see noise like this in Cropster. It’s not because the noise isn’t there, but because Cropster uses a different smoothing algorithm from Aritsan’s. Each system has its pros and cons.
Using 15s delta span artificially smooths the data from that same curve. This makes it easier to analyze (and helps roasters sleep better at night.)
The curves below are from a system with relatively little idle noise, shown in the 1s and 15s delta-span views again:
Delta span of 1s: Noisy and spiky but far less so than the Delta span of 1s: Noisy and spiky but far less so than the previous example with the 1s delta span.
Low-noise, high-quality data at 15s delta span
The Bottom Line
There is no universal set of optimal settings. You must customize the settings for your probe’s responsiveness, the level of background noise, and the software you use. Of course, you should attempt to minimize background noise and use the lowest practical delta span or ROR interval.
NB: Even if you don’t see obvious spikes in your ROR data, you may still have a serious problem with idle noise.
How to optimize software settings to analyze past curves
There are two types of data analysis I do on a roast curve: looking for a trend and looking for an event. By trend, I mean the shape, or changes in shape, of an ROR curve over a period of time. An event refers to a point in time, such as when an ROR crash or flick began. When looking at trends, i’ll make use of a higher ROR interval and when looking at events, I’ll typically use a lower ROR interval. .
Events
Let’s look at an event —an ROR crash— in Cropster. Cropster and Artisan calculate ROR curves differently, and at this time Crospter’s ROR-interval options range from 10s to 60s; quite a bit higher than those of Artisan. In this case, we’ll use a 10s ROR (the lowest in Cropster) to determine as precisely as we can when an ROR crash occurred.
The red arrow indicates the beginning of an ROR crash. Viewing such an event in the 10s ROR view can help a roaster more precisely determine how to time gas settings next time to prevent the crash.
Here’s an example of looking at a trend in Cropster, looking at the same curve with a 30s ROR interval:
The arrows approximate the ROR’s slope at various parts of the roast. It’s easier to discern a trend such as an ROR slope in the 30s ROR view than in a shorter interval such as the 10s view.
Another event you may look for in a completed curve is the beginning of first crack. Here is an example of using a 10s ROR interval in Cropster to decide the precise beginning of first crack
Note that the roaster chose to mark first crack after the ETROR trough. If the trough seems to have been triggered by a decrease in gas, it is sometimes sensible to mark first crack after the trough. Details on this some other time.
Was it the green? The roast? The extraction?
May 18, 2019
Was it the green? The roast? The extraction?
Photo credits: @andrewrizer
Often the most difficult part of improving a coffee is diagnosing how various inputs created a cup’s qualities. For every coffee I taste, I think about how the five main inputs (green, roast, grind, water, and extraction) contributed to the cup, and especially how any of them may have inhibited cup quality. My understanding of the role of each of those inputs is always evolving, and there is tremendous overlap among their effects.
Rather than simply being pleased with one’s own coffee, I wish every roaster and barista would default to thinking two thoughts immediately after tasting one’s own coffee in a work setting:
“How could we have made that better?”
“Which inputs (green, roast, grind, water, and extraction) should we change to improve the result?”
The effects of some inputs are sometimes easy to isolate and identify, and sometimes very difficult. Here are a few examples of ways to diagnose cause and effect in the cup.
Smokiness
Smokiness is always a result of roasting. Smokiness is distinct from “roast” or “char.” Roasts taste smoky due to insufficient airflow or excessively dark roasting (roast a batch dark enough for long enough, even adequate airflow won’t prevent some smokiness from creeping into the cup.) Some “clean” or “smokeless” roasting machines yield smoky coffee due to the beans dwelling in too much smoke for too long. Some such machines are better than others, but we can save that discussion for another time. Char and carbonized flavors are also always caused by roasting.
Acridity
A related flavor, “acrid” is usually created by roasting, but sometimes caused by excessively-hot brewing water. To taste acridity, set an espresso machine hot enough to deliver sputtering, hissing water. Ensure the portafilter is as hot as possible before brewing. Try pulling long (3:1) shots at that extreme temperature setting and look for a harsh, bitter, slightly stomach-turning flavor.
Flavor defects due to water chemistry
Certain “chemical” or “mineral” flavors are always due to water problems. Perhaps the most common is the classic defect “dish soap residue”. Sussing out the causes of these flavor taints is easy: you may use a quality bottled water as a control, and if dish-soap residue is a concern, taste the coffee in a paper cup instead of ceramic.
Vegetal flavors
Vegetal flavors usually come from roast underdevelopment, sometimes from low-quality green (especially wet-hulled coffees), and occasionally from poor water chemistry. For example, distilled water often produces vegetal flavors that don’t show up in the cup when using water with greater mineral content. To test whether vegetal flavors are inherent in a bag of green or due to roast underdevelopment, simply do a darker sample roast of the coffee and see if the vegetal flavors are still present.
Astringency
Astringency may be due to unripe cherry, an underdeveloped roast, or channeling. To find the source of astringency, I would do the following, in order:
To rule out channeling, cup the coffee— don’t taste it as a percolation brew. Immersion brews don’t channel.
If the coffee is still astringent, test roast development by sample roasting a darker batch of the coffee. Then cup it again.
If the coffee is still astringent, the likely culprit is underripe cherry.
Extremely low-TDS water can magnify astringency, but I’m honestly not sure if water can create astringency by itself.
Removing grind and water quality as factors
At a cafe or the QC lab of a roastery, if you always taste coffee by cupping (and thus avoid channeling) and have proof that your water quality and grind quality are excellent, then diagnosing the sources of cup qualities is easier, as you can focus merely on green quality and roast quality.
Side note: consider assuming your grind and water quality are suboptimal, and test them. When is the last time you blindly tasted coffee made using your water vs. various quality bottled waters or water recipes, such as the easy, excellent recipe favored by Barista Hustle? Did you invest a couple of hours to properly align your grinder when you last installed new burrs? And were those burrs installed in the past few months? Unless you can answer all of those questions favorably, please invest a few hours to test and improve your grind and water quality.
*
This post highlights a small sampling of ways the five inputs affect cup quality. There are countless such cause-and-effect relationships to consider the next time you make and taste a coffee. I hope this post offers a helpful starting point for diagnosing and improving your coffee.
Comments are welcome and encouraged.
Berlin Roasting Masterclass, June 8
Apr 28, 2019
I’m pleased to announce I’ll be offering a roasting masterclass in Berlin on June 8, at the venerable Five Elephant roastery. This class will feature a few new, exciting elements, such as:
A comprehensive system to permanently banish ROR crashes, flicks, and underdevelopment.
A cupping of the upcoming Roast Defect Kit (if you can’t make it to Berlin, you can order the RDK through regalia.coffee to get on the list.)
Free slices of Five Elephant’s legendary cheesecake.
A second cupping of roast samples, both good and (intentionally) bad, of a few choice, pricey coffees. I may even roast a natural for this, but thankfully we have the cheesecake to cleanse the palate.
See you in Berlin, and please remember to stop by the Decent Espresso booth at WOC for an extraordinary tasting experience.
Why we care (or don’t care) about seasonality
Apr 28, 2019
*A guest post by Ryan Brown, author of Dear Coffee Buyer*
I can’t help myself from occasional banter with baristas. Often this leads to playful arguments, and while I’d like to think that I usually win these arguments, I painfully remember a time I was wrong. In late fall, while visiting a cafe & roastery, I asked how they had come into possession of what was being marketed as a new crop Kenya.
The best Kenyan coffees typically begin harvesting in late November and arriving in February. Despite the esteem for the country’s quality, it may surprise you to learn that a huge majority of what you’ve ever tasted comes from a pretty small area surrounding Mt. Kenya, so there’s little fluctuation in this timing. It is entirely possible the coffee was from Kenya’s fly crop—its small, mid-season harvest that is rarely purchased by specialty buyers, as the quality is considered predictably lower than the main crop. But still, it was extremely unlikely that this was a new crop of Kenya being offered in early November. I insisted to the barista that it had to either be a fly crop selection or else a coffee from the previous year. A lengthy disagreement ensued with the barista, whom I would later learn was also the coffee buyer Whether the coffee was fly crop or old crop is beside the point. I was wrong to ask the question at all. (Granted, I wasn’t trying to make a point when I asked, it was merely curiosity.) As I note in Dear Coffee Buyer: A Guide to Sourcing Green Coffee: “I’ve generally been able to rely on coffees from Ethiopia and Kenya lasting a very long time after harvest.” But what about all of this talk of seasonality? Isn’t it important for me to buy the right coffees at the right time? I address these questions in DCB:
Seasonality in coffee is an attempt to apply standards to how fresh green can, or perhaps should, be. Most attempts at seasonality standards are based on duration of, or at least relation to, recurring harvest cycles. For example, some roasters may deem a coffee “seasonal” only if it is within six months of harvest.
This nomenclature is too arbitrary. Such rules don’t justify the presence on your menu of a coffee that’s only three months from harvest but has faded, lost its character, or, even worse, picked up papery, aged flavors. Likewise, the rules are cruel to a coffee that is twelve months old but still vibrant, clean, and free of any hint of past-crop flavor. In my early days as a coffee buyer, I attempted to create a schedule of origins and their corresponding seasonality calendar, but I realized that the best solution was to do away with any consideration of time, as it missed the point. We care about seasonality because we care about cup quality. Understanding the seasonal crop cycles will naturally inform your purchase decisions, but if you set strict rules for how long after harvest you should roast coffees, you’ll either be unfairly cruel to some, too lenient on others, or both. “A coffee should be considered seasonal so long as the cup is vibrant, shows structured acidity, and is free of any signs of age (paper, bagginess, astringency, etc). It doesn’t need to be any more complicated than that.”
Click on image below to learn more about Dear Coffee Buyer
Extraction Curve Analysis
Apr 07, 2019
Most of my work over the past ten years has involved analyzing roast-curve data for clients. Those years spent analyzing tens of thousands of curves have helped me identify consistent, verifiable relationships between curve shape and cup quality. Regardless of a clients’ roasting goals, that experience has usually made it easy to help the client immediately improve upon a roast simply by looking at a curve and suggesting alternative settings.
As I gain experience on the DE1, I’m learning to read its tablet’s curves and benefit from them. Below is a discussion of the most typical curve shape (ie a bad one). I think of this shot as the espresso equivalent of a roast curve with an ROR crash and flick. Mind you, the art and science of analyzing extraction curves is much more immature and speculative than that of analyzing roast curves; we’re still deciphering what all of this means.
This shot was generated using a flow profile. The green line represents pressure and the blue line indicates flow. The red numbers indicate important feedback.
The volatility in the pressure curve indicates channeling during preinfusion. Despite being in flow mode— which helps “fix” channels as they form— a fair amount of channeling still occurred. I have little doubt this shot suffered from poor puck prep or too many clumps in the dry grounds.
The collapse in flow after preinfusion likely indicates the grind is too fine (note the peak pressure of twelve bar), causing too much puck compression to allow the desired flow rate to occur. The high pressure could also be due to too large of a dose, but I’m assuming we use a consistent, appropriate dose.
The phase from 25s to 40s where the pressure declined gradually is what John calls the “healthy extraction phase.” On some shots, the gradually declining pressure does, in fact, seem healthy— we believe it indicates no significant channeling while the puck erodes. On this shot, it’s debatable how much of this phase reflects “healthy extraction” and how much it indicates the puck is too compressed and/or still absorbing liquid (ie incomplete preinfusion). The steep pressure drop after #3 almost certainly indicates the formation of channels as the puck erodes.
We are confident that we prefer shots with smoother pressure curves, steadier flow after preinfusion, more gradual pressure decline after the pressure peak, and smoother pressure curves. Those observations have proven valid in both directions— when we see those curve features, the shots generally taste better. And when we taste numerous shots of a given coffee, the best-tasting shots turn out to have had such curves.
It’s still early days in my Decent Education, but the DE1’s graphs have already made me a better barista, and it’s a lot more fun and interesting to pull shots with the feedback of the DE1’s graphs.
For reference, the graph below is what I would consider “excellent',” and it coincidentally (?) looks quite a bit like a steadily declining ROR curve. Cropster for espresso, indeed.
Introducing the Litmus XTS Spray Head
Mar 11, 2019
Litmus Coffee Labs is excited to announce that we’re finally ready to sell our spray head compatible with the Fetco XTS batch brewer. Dan has been refining the spray head for the better part of a year and it has been in the hands of approximately fifty beta testers for a few months. All of the testers have been thrilled with the improvements in their Fetco batch brews, and through their experience we’ve learned how to optimize the product. We’re offering a limited production run of 100 spray heads that will ship immediately. The next several hundred orders will ship within a couple of weeks, on a first-come, first-serve basis.
Why the Litmus XTS Spray Head?
For years, baristas have lamented Fetco’s change from the old flat-plate spray head to the Cascading Spray Dome (CSD). Our spray head radically improves the CSD’s performance by providing a more uniform spray to yield a higher and more even extraction with more clarity and less astringency.
Testimonials
From Kris Wood of Black Fox Coffee
"From a coffee lover’s perspective, the clarity of my filter coffees has improved drastically due to the even extraction. Coffees that were already very good are now excellent. From a business side, our TDS went up by 0.12. That brought our dose weight down by 3.9% saving thousands a year. It should be triple the price."
From Dave Stallings, Passenger Coffee
"It is hard to exaggerate the positive impact that the spray head has had on our batch brewed coffees. Of course we expected a more even bed and thus more even and balanced extraction, but this spray head has delivered on levels far beyond that: our extractions have increased across the board while also finding a focus, clarity, depth of sweetness, and cleanliness of finish that we have never before experienced on our batch brewer."
From Will Shurtz, Methodical Coffee
"I really love how much of an impact the spray head had on the quality of our batch brew coffee. There was a noticeable increase in the clarity of flavor of our coffee. So much so that multiple customers mentioned the difference they detected once we applied the spray head to our brewer."
Flow Comparison: The original CSD sprays in 12 large streams, while the Litmus device catches all the flow from the CSD and distributes it in 19 streams (apologies for the steamy video)
Caution before ordering:
We've encountered a small percentage of CSDs with an unusual design. Please take a look at your CSD before ordering. If you have one of the CSD's with the small circles on the bottom, it is not compatible with our mod. Please let us know if you have such a CSD, we’d like to know how many are out there.
Here's a short video showing how to install the part
The Litmus XTS Spray Head snaps easily onto your existing CSD. Before snapping it in, please ensure the two parts are aligned such that the four middle holes are exposed, as shown in the video.
Please click HERE to purchase the Litmus XTS Spray Head.
Roasting Classes during SCA Boston!
Mar 11, 2019
I’m pleased to announce I will be holding two roasting masterclasses in Boston this April during the SCA Expo.
These will be very advanced classes, complete with a tasting of the newest Roast Defect Kit and some new strategies for managing ROR crashes. I’m getting closer to being able to completely prevent ROR crashes, and I’m excited to share these new findings and strategies with advanced roasters.
Among other topics will be a strategy that argues for ignoring first crack on some roasts :0. It will be an interesting conversation.
A more effective way to align your grinder
Jan 30, 2019
From Scott
I recently ranted, I mean posted, on Instagram about the unnecessary frustrations of aligning the burrs of an EK grinder. Mahlkonig designed the EK for grinding spices (not coffee) and was flat-out lucky that I took a chance on buying an EK for coffee in 2010. The first day I used the EK in Montreal I achieved 23% extractions in my Fetco and word spread rapidly throughout the coffee industry. Cafes all over Montreal began buying EK’s and then Mahlkonig lucked out again when Matt Perger used the EK in his excellent World Brewers Cup routine. Since those events, Mahlkonig has sold many thousands of EK’s and has had the nerve to raise the price without addressing the issue of the machine’s atrocious alignment. I’ve used over 100 EK’s and would estimate that at most 10% of them were well-aligned right out of the box. The terrible QC of EK manufacturing has cost us collectively tens of thousands of hours trying— often unsuccessfully— to accomplish something that Mahlkonig could have accomplished in minutes per grinder sold.
When someone has manufactured a commercial grinder for less than $5000 USD that grinds better than the EK and is also well aligned out of the box, please contact me: I will happily promote your machine for free after testing it to my own satisfaction.
Over the past nine years baristas have become more aware of the issue, and some homegrown re-alignment methods have partially solved the problem. Unfortunately, those methods require an hour or two each time the burrs are removed or replaced. (Matt’s tutorial HERE is excellent.)
Upon reading my rant/post, Mitchell Hale commented on the Instagram thread about a method of sanding the burr carriers to realign the burrs. I asked Mitchell to share that method as a guest blog post and he graciously gave his time to writing this how-to. I have not tried the method yet (I don’t have an EK at home and my current home grinder is well aligned) but I have faith that it will become the new standard for burr alignment for many flat-burr grinders, not just the EK. This method may take three to four hours, but once it is done, you will not have to repeat it each time you remove or replace burrs. This seems like an excellent investment of time.
Mitchell has agreed to reply to some comments here, but please be sure to read this post several times before asking questions. Please don’t ask questions such as “will this work on some other type of flat-burr grinder?” The answer is: “probably” but neither Mitchell nor I have tested this method on a variety of grinders. Posts like this are to spur ideas and conversation, nothing more. Do some research, try at your own risk, and give back to the community by sharing your results and insights. Thank you.
Guest Post by Mitchell Hale
Before we begin I want to give credit and thanks to the community at kaffee-netz.de, and to Jürgen Peter Ohler (Jupe3.0) in particular, for coming up with this idea in the first place. I’d have never been able to put together this guide without their pioneering of the method.
I’d like to introduce you to a simple and straightforward way to align your grinder that uses the inherent properties of the grinder itself, rather than relying on user observations like methods such as marker alignment. This method uses readily available supplies to allow the burrs to alter the grind chamber and the burr carrier so that the burrs are aligned parallel to each other and perpendicular to the drive shaft without shims. To achieve this, we’ll be attaching sandpaper flat to the back of the burrs in two different configurations (see diagram) to sand both mounting surfaces.
This method works easily with any grinder with an EK-like burr pattern. With the inner burr fixed in the grinder chamber and the outer burr on a spinning carrier that goes over the drive shaft. EK43, Bunn G1, etc.
Sandpaper of several grits, I used a bunch of big packs from the hardware store, but a multi-pack would be ideal. We’re only going to need a couple sheets of each grit size. Make sure it's wide enough for your burrs. 98mm for EKs, 80mm for Bunns, etc.
Adhesive remover, I used Goo Gone, available at https://www.amazon.com/Goo-Gone-Pro-Power-Spray-Gel/dp/B00SPHYQXM and most anywhere you can get cleaners. I do want to note that Goo Gone is not a food safe product, but you can clean it off thoroughly. If you do feel concerned, I find that canola oil does a good job of stripping the adhesive as well. Be sure to clean it thoroughly too, for different reasons.
An X-Acto style knife. Most hobby stores, hardware stores, and office supply stores will have something suitable.
Some rags to wipe up the metal filled cutting oil. Expect to throw them away after, so get something cheap.
Masking tape.
The thinnest tape you can find. It has to fit between the sweepers on the burr carrier and the outer burr.
A screwdriver for the burr chamber and another for the burrs themselves. I highly recommend a torque screwdriver for the burrs to put them in with more even tension. It's not strictly needed, but if you can get even a cheap one you can be a lot more confident you’re not over tightening one side.
UNPLUG YOUR GRINDER AT THIS POINT. LEAVE IT UNPLUGGED UNTIL FINISHED.
Now, for the chamber sanding
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Cut out 6 squares each of about 220 grit, 320 grit, 400 grit, and 800 grit sandpaper that will fit the entire burr on them. If you like shine and don't mind the time it takes, throw some higher grit in there too.
Take the outer burr carrier out of your grinder, remove the spring from it, and set it aside. Then unscrew the inner burr, you'll be attaching the sandpaper to this burr first.
Take one of the squares of your 220 grit and spray the back lightly with spray adhesive, then press your inner burr on it. Wait for it to dry. Then cut off the excess sandpaper from the edges and middle leaving only a ring of it.
Tape your inner burr to the outer burr that's still screwed into the burr carrier. You can work around the sweeper post things with masking tape, or try to get the tape under them with the thin tape.
Apply cutting oil to the sandpaper.
Put the assembly of two burrs in the burr chamber (making sure the spring is out of the carrier) and spin it around with gentle pressure. Take it out from time to time to wipe off the oil and metal. Continue until the sandpaper is worn out.
Repeat 3-6 two more times to use 3 discs. You'll need the adhesive remover to clean the burr to attach the next disc.
Repeat steps 3-7 for each size of sandpaper. You should use 3 discs for at least 220 and 320, and can probably go down from there. Those sizes do most of the work and the rest polish.
Now your chamber is sanded to be perpendicular with the driveshaft. But your carrier does not perfectly match, not yet.
Now, for the carrier sanding
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Screw your inner burr back into the grinder. Ideally with a torque screwdriver to keep things even. Unscrew the outer burr from the carrier
Take one of the squares of your 220 grit and spray the back lightly with spray adhesive, then press your outer burr on it. Wait for it to dry. Then cut off the excess sandpaper from the edges and middle leaving only a ring of it.
Tape the outer burr, without carrier, to the inner burr. This can be a pain to pull off depending on the individual grinder, and you'll need some thin tape. The sweeper posts will need to be able to fit over the tape this time.
Apply cutting oil to the sandpaper.
Put the carrier over the two burrs that are affixed to the chamber, apply gentle pressure and spin it to sand down the carrier. Same way you did with the chamber sanding.
Repeat with multiple grits and multiple discs of each grit the same way you did with the chamber.
Your carrier now has a parallel surface to your chamber. Which is also perpendicular to the driveshaft! Congratulations, your grinder is aligned the best it can be this side of a machine shop!
Final steps and notes
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Don’t worry about matching things like my grit numbers exactly. They’re there as guidelines for cutting grits and finishing grits.
Your zero will change significantly. We’ve removed material from both burr mounting surfaces, so they will be physically further apart at the same settings until rezeroed.
Make sure to clean your grinder before using it.
Make sure to clean your burrs thoroughly of both adhesive and adhesive remover before reinstalling them.
Make sure to flush your grinder with at least a few doses of coffee, ideally more, before using it.
When you're applying spray adhesive, have it in a box or other contained area to not make a mess.
Rubbing alcohol, acetone, dish soap, etc all do nothing on the spray adhesive. You do need an adhesive remover or oil. Trust me, I thought I wouldn’t need it.
If you use any water on your burrs for cleaning, dry it off right away. Especially for standard uncoated tool steel burrs.
You can repeat the chamber sanding once the carrier is done for a theoretically slightly more perfect surface, but it's not really necessary.
Sanding times are for standard sandpaper, and should last several minutes to 10-20 minutes tops for a sheet. If using any especially long lasting sandpaper and it isn’t wearing out at all over several minutes, you can stop after a few normal sheets would have worn out and move on to the next grit.
When cutting sandpaper around the burrs, make sure not to get it too tight. Remember, the burrs have to fit into the sanded area. If the sandpaper is cut too tight and leaves some of the burr face uncovered, the burr will end up sitting on the unsanded edge around the burr. It’s ok if it goes just slightly beyond as well. So if in doubt, it’s better to have a disc slightly larger than needed, than one slightly too small to work.
Sydney Masterclass, February 3rd
Jan 17, 2019
I’m pleased to announce that I’ll be offering a Roasting Masterclass in Sydney at Collective Roasting Solutions on February 3.
This will be a very advanced class, complete with a few new strategies for managing ROR crashes. I’m getting closer to being able to completely prevent ROR crashes, and I’m excited to share some new findings and strategies with Australia’s best roasters this February.
Among other topics will be a strategy that argues for completely ignoring first crack. :0
I like cascara. It’s not the most “interesting” beverage, as it often lacks nuance and liveliness. However, there is something comforting and (energetically) warm about cascara that makes me want to drink it every morning.
My partner Paolo at Regalia often includes a bag of cascara as a treat when he mails me roasted coffee samples. The cascara he sent me last week is like no other I have ever tasted. This cascara is the first one I have ever found to be interesting, with some zingy acidity and crispness reminiscent of some African coffees.
Here is Paolo’s description of the cascara and a link to Regalia’s website. Enjoy.
Region: Sabanilla del Poas Altitude: 1500 MASL Process: Red Honey Varietal: Villa Sarchi, Caturra, Catuai
Perhaps one of the finest cascaras on the market: the Chacon's cascara is incredibly clean, with a honey-like sweetness, and a fruit quality that resembles peach and kumquat.
Dona Francisca and her husband Oscar Chacon of the Cumbres del Poas micro mill are 3rd generation coffee producers. The Cumbres del Poas micro mill is located in the Sabanillia de Alajuela in the Central Valley region of Costa Rica. Both Francisca and Oscar believe in preservation of the environment. They were some of the first pioneers of high-quality honey and natural-process coffees in Central America back in 2009 when they started experimenting with special processes. Water use at the mill is minimal, since their coffees do not undergo the washed process. During the harvest of their coffees they will measure the Brix content in the coffee cherries to determine the best time to pick their coffees to obtain the sweetest and most fruit forward profiles.
Rather than processing their cascara like they would their normal parchment, the Chacons treat theirs like one would approach dried fruits. These are lightly washed and quickly dried on parabolic driers.
RECIPE
If you're new to brewing cascara, note that you are easily able to do so like one would steep tea in a satchel:
20g Cascara
360ml boiling water
8:00 steep time
Pro Tip: If you filter the final product through a paper filter, it will enhance the cascara's fruit-quality.
(Note from Scott: I use a little lower ratio of cascara:water but steep it longer than Paolo does. Cascara doesn’t “overextract” so don’t be afraid to leave it in a thermal mug all day.)
Why Spin the Slurry?
Jan 09, 2019
Why Spin the Slurry?
A guest post by Jonathan Gagné
From Scott: The history of The Spin is murky…although it’s often called the “Rao Spin,” I did not invent the spin. It’s likely that James Hoffmann was the first person to spin the slurry. Almost everyone to whom I’ve shown The Spin has immediately adopted it. It’s easy to execute well and it works, pretty much every time.
Jonathan Gagné, an astrophysicist based in Montreal, came to my roasting masterclass this past November. I’ve been fortunate to befriend Jonathan, as I’ve always wanted to have an astrophysicist on speed dial to call when I have a question about how things work :). I’ve been helping Jonathan with his coffee making and he’s been providing some great coffee-analysis resources, some of which I hope appear on this blog.
I asked Jonathan to explain why he believes The Spin works and we decided to publish his answer as a guest post here. This post and a few more technical discussions on coffee brewing are also available on his blog at https://coffeeadastra.com.
Why Spin the Slurry ?
Summary
In this post we will discuss the physics behind why spinning the V60 during a brew is a useful method to obtain a more uniform extraction. While spinning is helpful, it’s important not to overdo it - it can cause fine coffee grounds to migrate to the bottom of the slurry and clog the filter, slowing the drawdown and imitating a brew made with a lower-quality grinder.
Spinning the slurry during a V60 brew is useful to minimize the channeling of water that can lead to an uneven extraction. The reason why this is true can be understood with the help of physics.
A rotating slurry will experience a centrifugal force*, which means that every drop of water and every particle of coffee will suffer a force that pushes them outwards. In physics, the strength of centrifugal force is more important for heavier objects, and because of this, water will tend to migrate outward more than coffee because water is heavier.
When you brew coffee, the main cause of channeling is that dry coffee repels water more than wet coffee does. The physics behind this effect are not fully understood: they are related to the fact that molecules of water bond with each other, and dry coffee doesn’t bond with them in the same way. At first pour, water might begin travelling through a tiny hollow on the surface of the dry coffee, and then it will prefer to keep traveling through that same tunnel, because the rest of the coffee bed is still dry and repels water. In practice, a coffee bed will often develop several channels if you don’t take steps to avoid it.
When you rotate a channeled coffee bed, the water flowing down the narrow tunnels is forced out of them by the centrifugal force, and the water will wet some of the dry coffee. This horizontal re-mixing of the slurry will cause channeling to decrease overall.
There is, however, a drawback if you spin too much. As mentioned earlier, heavier things are more affected by the centrifugal force. The largest coffee particles will thus experience a stronger pull toward the walls of the V60. In a slurry where coffee is mixed with water, this effect will be slightly reduced by water friction. Think of trying to run in the sea - the friction water exerts on you will slow down your movement, especially if you present it with a large surface, for example by wearing saggy pants. The friction is however not strong enough to completely stop the migration of particles based on their size, and the larger coffee particles will be sent outwards.**
This whole situation presents the smallest particles with an opportunity: the larger ones having moved out of the way, fines will sink down to the bottom of the V60, where they will be free to do their worst at clogging the paper filter. This will significantly slow down the flow of your brew.
As an illustration of this, I recently brewed a few V60s with a prewet-plus-two-pours method, performing a spin right after the prewet, and right after each of the two pours. At first I did not pay too much attention to how long or how strong I was spinning, and I experienced large inconsistencies in my brew time (up to ~20 seconds), which led to inconsistencies in average extraction yields by about 0.7%. I was controlling everything else, including the height from which I poured, the flow rate, timing, grind size, slurry temperature, etc.
I then tried timing my spins, and found that using seven-second spins resulted in a 5:18 drawdown time, while two-second spins resulted in a much shorter 4:28 drawdown time! This is a nice demonstration that fines can migrate and clog your filter if you spin too much. Adjusting the grind size appropriately to maximize extraction yield and avoid astringency, I found that the two-second spins resulted in a brighter and more enjoyable cup.
In summary, you want to spin just enough to break the up channels, but not so much that fines clog the bottom of the filter.
*NB: I can already hear the interwebs shouting “CENTRIPETAL NOT CENTRIFUGAL”. Both concepts are valid and useful tools: when you stand outside of a rotating system and want to describe forces acting on that system that keep it together, the concept of a centripetal force (directed toward the center) is appropriate. It describes the external force that allows the system to keep going in this rotating motion without splattering everywhere around. In our case, this force is provided by the walls of the V60, preventing the slurry from flying around and messing up your counter. If, however, you take the point of view of the things rotating (the water and coffee), then the concept of a centrifugal force becomes very useful. You can then describe the system as if it was not rotating, by just adding a slight modification: you add an artificial “pseudo force”, also called an “inertial force” that points toward the outside, in our case the “centrifugal force”. It is often called an “inertial force” because it arises from the fact that your frame of reference (the V60 in this case) is rotating (in technical terms, it is “not inertial”). A “pseudo force” is by no means a false thing or an invalid concept, as long as you understand where it arises from and use it carefully — in fact, one can even see gravity as a pseudo force (Einstein realized that), yet it is very useful in everyday situations to view gravity as just a normal force.
** The mass of a coffee particle is proportional to its volume, which is itself proportional to the cube of its size. The water friction that the particle experiences is proportional to its surface, or to the square of its size. As a consequence, a particle three times larger will be nine times more massive and will feel nine times more centrifugal force, but only six times more water friction. If you combine the two effects, it will therefore be pushed outwards 9 - 6 = 3 times more.
Melbourne Masterclass, February 9
Jan 08, 2019
I’m excited to visit Melbourne during MICE this February, because:
It’s a blast to explore Melbourne’s food and coffee scene.
I’m still hoping some Australian family will adopt me and save me from Trump
Veneziano Coffee Roasters is hosting my Masterclass on February 9 at their gorgeous headquarters and roastery.
If you’re in Melbourne during MICE, bring your most pressing questions about roasting and prepare to be challenged by some radical new ideas about controlling roast curves.
Also, please visit Decent Espresso at MICE. We will be demonstrating both espresso and filter brewing on the DE1+. You won’t want to miss it.
BARATZA FORTE VS EK43: WHICH IS BETTER?
Jan 06, 2019
Disclaimer: While I don’t take requests for equipment recommendations on social media, occasionally I like to share my experiences with various coffee equipment. I do not have a financial relationship with Baratza or Mahlkonig, but Baratza was once kind enough to upgrade a grinder for me because the first model I bought wasn’t quite right for my needs (I bought a Sette, which is designed for espresso, but I wanted a grinder that would be equally good for espresso and filter brewing.)
*****
For the past few months I’ve been using a Baratza Forté at home. I chose the Forté because I wanted a grinder that would do a good job grinding for both drip coffee and espresso. In addition, I needed a grinder capable of producing extremely fine grinds to pull “blooming espresso” shots on the DE1PRO. (A blooming espresso shot involves a 30-second pause after preinfusion, and requires an extremely fine grind.) Neither an EK43 nor most professional or consumer grinders can grind fine enough to pull a good blooming espresso shot. Perhaps an EK43 with perfectly aligned burrs could do it, but such an EK43 is virtually a unicorn.)
I had expected the Forté to do an adequate job, and to eventually want to replace it with a professional grinder, but I dreaded putting a large machine on my small kitchen counter. Much to my surprise, the Forté has not only performed better than any pro grinder I have ever owned, but I have been making the best v60’s of my life using the DE1PRO + Forté. (More on the DE1PRO as the world’s best drip brewer in a future post.)
For reference, I’ve owned well over forty professional grinders and I was the first person in specialty to use an EK43 and recognize its ability to achieve exceptionally high extractions. (Note: Mahlkonig did not design the EK43 for coffee and the machine’s success was a lucky accident.) I used to be fond of the EK43 but now avoid it whenever possible.
While the first EK43 I owned happened to produce impressive results, I’ve since used about one hundred EK’s and I’ve realized that I was lucky: that first machine happened to have been well aligned. Only about 10% of the Ek43’s I’ve used since then have had such good alignment. Poorly aligned Ek43’s are the norm, a problem Mahlkonig has chosen not to resolve, and a problem that has caused their quality-oriented users endless grief and wasted time, as users have had to personally realign the burrs both out of the box and upon each burr change, a frustrating process. There is no excuse for selling such an expensive grinder that usually underperforms right out of the box. Nor should customers have to spend so much precious time bringing the grinder’s performance up to a reasonable standard.
Because of the Ek43’s alignment issue, I desperately wanted to avoid overpaying for a machine that would give me fits. I’m pleased to report that the Forté extracts higher than any EK43 I have ever used, makes tastier coffee than any EK43 I have ever used, and can grind much finer than most EK43’s.
The Forté also has a few clever features such as a built-in scale for accurate grinding by weight, an anti-static receptacle (EK43’s produce so much static that their exit chutes look like chia pets), and the option to grind by time or by weight, with multiple programmable presets for each. I can’t say whether most Fortés are well-aligned straight from the factory. I can only report on my experience.
Sure, I probably wouldn’t grind 100 lbs/day in a Forté in a busy café, but if you’re looking for a great home grinder, just know you don’t have to buy a commercial machine or convince your spouse that it’s reasonable to have an enormous, $3000 grinder on the kitchen counter.
Thanks for reading.
NB: Please do not ask for equipment recommendations in the comments section. I don’t claim to know much about Baratza’s product line, competitors’ offerings, etc. Also, I have the Forté AP but also have both burr sets and both receptacle styles (portafilter holder and plastic bin). Sorry for the confusion about those details.
Online All-levels Roasting Class, January 19
Jan 06, 2019
I’m pleased to announce that I will offer an online roasting course this January 19th. With the help of my friend Lee Safar of Map It Forward and Elixir Specialty Coffee, we will broadcast the class through a private Facebook group. All ticket holders will have access to the class video and discussion forum for one month after the class airs.
Please join us online, or if you’re in Southern California, we’d love to see you in person. Live seating will be limited, so claim your seat ASAP. The class will be held at Steady State Roasting Co in Carlsbad, CA at 2pm.
Online tickets are $125 USD, live tickets will cost $175. During the class we will cup samples from the upcoming Roast Defect Kit by Regalia Company. The RDK’s coffee will be the Jeremias Lasso Gesha from Colombia. If you buy a virtual ticket and would like to receive the Roast Defect Kit in the mail to cup along with us at home, the kit will cost an additional $50 USD (making online and live tickets the same price.) Please click HERE to order the RDK. (Note: we are terribly sorry but cannot ship the RDK to South Africa, China, Russia, Greece, or Brazil.)
All ticket holders, live and virtual, will have access to the class video for one month through Facebook. Please note that if you live outside of the US and purchase the Roast Defect Kit, it will take approximately two weeks to arrive. I guarantee you will receive the RDK before your online class access expires (given that you will have access to the class for one month, there is no particular benefit to cupping the RDK on the day of the live broadcast.).
**ONLINE CLASS ACCESS WILL BE FROM JANUARY 19 -- FEBRUARY 18, 2019**
All ticket holders will also have access to a discussion forum on the private Facebook group for one month. I will field questions every day on the forum. The forum will provide a safe, friendly space for a high-level discussion about roasting, something difficult to find anywhere else. Students of past online courses have found the forum helpful for solidifying the class lessons, have enjoyed the community feeling, and many have shared their roast-curve progress on the forum.
The course will be appropriate for roasters of all levels. Although I am calling it an “all levels” class, this course will touch on methods more advanced than anything in the level-three SCA roasting course (those classes are basic) , and I guarantee your satisfaction.
The class will include:
Three hours of lecture and Q&A
Cupping and curve analysis of the "Roast Defect Kit" featuring good, baked, and underdeveloped roasts.
Methods to manage ROR curves
Advanced methods to prevent ROR crashes and flicks
How to modify roasting machines for better performance.
Pro tips to get the most out of Cropster and other roasting software.
How to adapt various strategies to different types of machines.
Click HERE for more information and to purchase tickets.
Coffee Nerd Gift Guide
Dec 18, 2018
Just in time for the holidays, I thought I’d share a few book and gift recommendations for you to get for the coffee nerd in your life. Or just gift them to yourself if that appeals. :)
If you’re serious about coffee and were to only ever read one book about it, make it this one. James Hoffmann is rightfully famous and popular in the coffee industry for his prose, his perceptiveness, and his uncanny ability to see the big picture clearly. The World Atlas of Coffee has tremendous breadth, covering everything from coffee origins and varieties to roasting and brewing methodology. Somehow James dives deep enough into each topic that the reader learns much of practical value and no topic is glossed over. Even seasoned coffee professionals will learn a lot from The World Atlas of Coffee. It’s a gem.
Zingerman’s Guide to Giving Great Service by Ari Weinzweig
Zingerman’s Deli is a decades-old institution in Ann Arbor, Michigan. It’s so impressively busy and efficient that it has inspired countless other entrepreneurs to copy its approach to food and service. If Zingerman’s had been established in New York or San Francisco, it would doubtlessly be one of the world’s most famous casual food businesses. While the food at Zingerman’s is pretty good (I will warn readers that the coffee is marginal), what sets the business apart is its service. Zingerman’s is the kind of place where you could interrupt any staff member at any time, ask any question, no matter how obscure or annoying, and receive a friendly, well-informed answer. Sometimes I wonder if the staff all microdose some kind of happy drug. Zingerman's Guide to Giving Great Service is a how-to guide to creating a complex, bulletproof service system. Their system manages to tackle every service-related concern imaginable, and once I read the book I understood how their businesses ran so flawlessly. In fact, in a fit of cheekiness, I tested the system at Zingerman’s Roadhouse. I went there alone for dinner (had I brought a friend I think they would have run away mid-meal by what I was about to do.) I was most difficult-but-polite customer I could be. I asked countless difficult, detailed questions about the food, I changed my order multiple times, I complained about the wine, I made special requests, and I generally pushed up against the precise boundaries of Zingerman’s service system in an attempt to get my server to go off script or show some frustration. My server never cracked or showed impatience. At the end of the meal, I left her a massive tip and confessed that I was testing the durability of the Zingerman’s service system. She laughed and said that by the end of the meal she had begun to suspect that was what I had been up to.
The bottom line: the system worked and my service was extraordinary. If you’re in service, this book is a must-read.
When I owned my first cafe and roastery in the 1990s, I read every decent book I could find about running a business. The one book that stood out from that era was The Fifth Discipline. It introduced me to the concepts of the “learning organization” and systems thinking. Prior to reading the book, I had been feeling a little burnt out from working long hours and had fallen into several ruts. For months after reading The Fifth Discipline I went to work with tremendous energy, inspired to apply what I had learned from the book.
The Fifth Discipline reminded me to make business decisions that resonated with my personal values, it inspired me to focus on continual learning, and it helped me focus a little less on finances and the daily routine, and a little more on operating the business in a more thoughtful, fulfilling way. I can’t recommend this book enough to business owners and managers.
Dear Coffee Buyer: A Guide to Sourcing Green Coffee by Ryan Brown
If one thing separates third-wave coffee from the rest of the industry, it’s the focus on procuring fresh, high-quality green coffee. The early 2000s brought a revolution in standards for green quality and in modern green-buying practices. In my 25-year coffee career, I’ve never met a more competent green buyer than Ryan Brown. Ryan’s palate is, of course, extraordinary, and every cupping session I’ve had with him has been an education for me. But Ryan’s brilliance as a buyer was as much about the strategies and systems he brought to green buying as it was about his cupping prowess. In Dear Coffee Buyer, Ryan teaches the reader invaluable lessons about risk management (e.g. it’s better to buy too little than too much of a coffee), communication (and why it is more important than a world-class palate for procuring great coffee), and strategies to help get green to arrive in good condition, when you want it. He’s also a gifted writer whose skillful prose and stories about traveling to origin keep the reader entertained and engaged.
Even if you never plan to be a green buyer, if you work in any capacity in the coffee industry, Dear Coffee Buyer is essential reading. It should be required reading for anyone who buys, roasts, brews, or teaches about coffee.
If, like me, you prefer to use a bottomless portafilter to help detect channeling in shots, you need a way to prop the portafilter so the basket is level while weighing and tamping doses. The Decent Portafilter Stand is the perfect solution. To dose precisely with minimal clumping, I recommend dosing into an intermediate container, shaking or banging the container to break up clumps (or if you’re not in a hurry, use the Weiss Distribution Technique) and pouring the de-clumped grounds into the portafilter basket. It’s difficult to pour grounds into the basket without some spillage, but the Decent Funnel solves this problem elegantly. Unlike the unwieldy, ill-fitting jam funnels many baristas use, the Decent Funnel is compact, ridged to lay securely on the rim of a portafilter basket, and weighted for stability. This is my personal favorite Decent product other than the espresso machines.
*Note: if you buy three or more products at a time from Decent, shipping is free to anywhere in the world. Decent also sells Dear Coffee Buyer and The World Atlas of Coffee here.
A few months ago Mr. Zubing Sun contacted me on Instagram, offering to send me a tamper. I’m usually skeptical of such offers, as I rarely find coffee accessories all that impressive. The Force Tamper is an exception. It allows the barista to achieve adequate tamping pressure while using precious little force. The Force Tamper works like an acupuncture needle in that once the barista applies just enough force, the mechanism takes over and jabs at the coffee bed with precise, repeatable pressure. The Force Tamper even makes the a satisfying “zing’ noise reminiscent of an acupuncture needle (or, perhaps the world’s scariest noise if you’ve been traumatized by an acupuncturist.)
My only gripe about the Force Tamper is that grounds frequently build up between the tamping face and the metal disc above it. That makes the Force Tamper less appealing for use in a high-volume cafe, but it’s still great for use at home.
I’ve been using this scale for over ten years both at home and for travel. It’s tiny, light, cheap ($11 USD), and durable. It’s frankly a more reliable scale than most of the semi-disposable $40—$80 scales baristas use in cafes. The AWS is not waterproof, but I’ve poured plenty of espresso and water on it over the years and somehow it keeps on ticking. Best of all, if you break the scale by dropping it or drowning it in liquid one too many times, you can replace it for a mere $11.
Happy Holidays, and don’t forget to sneak your own coffee into those family gatherings :0
Roasting Masterclass | NYC (12/22)
Dec 06, 2018
Roast Defect Kit available via the Regalia Company.
I'm pleased to announce the last Roasting Masterclass of 2018, to be held at the Regalia Company in NYC. This masterclass is unlike any other offered in the world. This will also be an unusually small class due to space constraints, so I promise to give lots of individual attention to all of your questions and concerns.
Whether you are a novice roaster or a veteran with decades of experience, you will leave with plenty of useful new ideas and methods to implement at your roastery.
The class will include:
Three hours of lecture and Q&A
Cupping and curve analysis of the "Roast Defect Kit" to demonstrate good, baked, and underdeveloped roasts.
Methods to manage ROR curves
Advanced methods to prevent ROR crashes and flicks
How to modify roasting machines for better performance.
Pro tips to get the most out of Cropster and other roasting software.
How to adapt various strategies to different types of machines.
Bring all of your curiosity and most pressing questions. I guarantee your satisfaction or your ticket is free!
Click HERE for tickets and info, and I hope to see you in New York!
How to Use Cropster To (Almost Always) Know Exactly When First Crack Began
Dec 06, 2018
One challenge to precision roasting is knowing when first crack began. Some roasting machines make hearing the cracks nearly impossible, but even when hearing the cracks is easy, knowing exactly when to mark the beginning of first crack can be debatable or subjective.
The importance of precisely marking first crack
First crack (FC) is perhaps the most significant event during a roast:
At FC beans release a tremendous amount of moisture and gas in a short period of time
The ROR is most likely to crash at FC (due to that same release of water vapor and gases)
Much smoke develops
The bean surfaces are delicate, and (in a classic-drum roaster) the drum is simultaneously very hot, a risky combination.
If the ROR is to crash, it will most likely crash just as FC begins (there are many exceptions to this, notably including some of this year’s Ethiopian coffees.)
Gas settings before and after FC
The timing and magnitude of gas adjustments around FC are critical…when roasting a coffee that tends to crash early in FC, I often advise clients to avoid lowering the gas in the window of time from 45 seconds before to 45 seconds after the beginning of FC. (The specific advice to clients is more nuanced than that, as the timing of adjustments depend on the timing of the crash and the rate of roasting. However, FC +/- 45 seconds suffices for this post.) Lowering the gas within that time window will exacerbate any potential ROR crash. Simply raising the gas at FC (presumably just before a crash begins) to mitigate the crash is a terrible choice— I won’t go into that here, but if you currently use that strategy, find a way to avoid a crash without raising the gas; if you match the curves well (ie. roast two nearly identical curves, one created by raising the gas at FC and the other without raising the gas) you’ll taste the difference. If you can’t taste the difference, cup the roasts blindly with someone with a more experienced and sensitive palate, something worth doing anyway. There’s more to roasting than creating an aesthetically pleasing ROR curve — how you create that curve matters tremendously. I consider raising the gas at FC “cheating,” in the sense that it may produce a great-looking curve, but harms coffee flavor. While a nice curve may be a prerequisite for an optimal roast (note: “optimal”, not “I think it tastes good”), it is not a guarantee of an optimal roast.
To time the gas settings perfectly throughout a roast, it’s critical to know precisely when FC occurred, or will occur. Having experience with a given coffee may help a roaster predict the bean temperature of FC. However, the curve leading up to FC and the ROR and ET readings at FC may alter the bean-probe reading at FC for a given coffee. I’d like to propose a system that is better than simply listening for FC or assuming FC will always arrive at a given bean-probe reading.
How to use Cropster data to precisely mark first crack
Several roasters have remarked on the behavior of the ET curve at FC; depending on the location and sensitivity of the ET probe, the ET curve may arc up during FC. (If you have an inlet-temperature curve, that may arc up even more.) You can see a version of that phenomenon in the curve below.
Close up of roast with proper FC marked.
Unfortunately, the timing of arc in the ET curve is not obvious enough to help one mark FC with precision. However, the ET ROR curve is usually sensitive enough to alert the operator of the imminent hump in the ET curve. Here is the same late-batch curve with the ET ROR curve shown (turning on the ET ROR in Cropster compressed the BT.ROR curve, so please ignore that.)
Close up of end of roast with ET ROR on
Note that the operator marked FC at 9:35, but I have placed a vertical line at 9:13 at the trough of the ET ROR curve. I believe that the ET ROR trough is usually the best indicator of the “real” beginning of FC. Some exceptions to this would be if the operator had decreased the gas shortly before the ET ROR troughed, FC began in a prolonged, erratic manner (as may happen with some coffees), or some decafs and naturals that crack gently or erratically.
I believe the ET ROR jumps for several reasons, but I don’t claim to completely understand the dynamic (there isn’t enough scientific evidence for anyone to understand it completely.) Part of the explanation seems to be that the release of moisture and gas from beans as they fracture increases the flow of hot air passing the ET probe. I’ve often wondered why the BT ROR crashes at the same time the ET curve jumps up. This may not be the complete reason, but I will speculate that the moisture escaping the beans cools their surfaces and, more importantly, deflects some of the hot air attempting to penetrate the beans. The combination of cooler moisture and deflected hot air causes the BT ROR to crash, while the greater amount of hot air passing the ET probe causes the ET curve to jump.
Here’s another example of a Cropster curve with and without the ET ROR shown:
Rwanda FC marked too late
I believe FC really began at 8:05… this coffee is a fresh-crop Rwanda that crashes unusually late in FC.
What if I mark FC at the wrong time?
If you mark FC too early or too late, simply add a new “First Crack” comment in Cropster… the software will assume the new FC timing is the proper one and will adjust FC and the live DTR counter accordingly. You may clean up your redundant comments by making a new “dummy” comment at the exact time of the incorrect FC comment. For example, in the roast above, if I want to eliminate the FC comment at 8:43, I may choose to make a new comment at 8:43, type “x” and then press “Text Comment”. That will add the comment “x” at 8:43 and delete the old FC comment.
**Breaking news: if that process sounds clunky it's about to get smoother. The Cropster team just informed me that the next update to RI4 (due within two weeks) will allow comment editing on the fly.**
Coda
Since I have begun teaching clients to mark FC using the trough in the ET ROR, they have been better able to keep their ROR’s smooth, avoid crashes, and even roast a little darker without an ROR crash or flick. Mind you, this strategy doesn’t always work, particularly if one lowers the gas shortly before the crack. In such cases, some experience with this method will help.
Many thanks to Jerome of Structure Roasters for his tutelage in some of the scientific dynamics at play during first crack.
Roasting Masterclass | Vancouver (10/9)
Nov 28, 2018
Somehow despite the cold. Canada is calling to me for the second time in a month. Perhaps it’s the polite people, or perhaps it’s just nice to spend time in a country with a reasonable leader. :0
I’ll be offering a Roasting Masterclass in Vancouver on Sunday, December 9. Given the late notice, this will surely be an intimate affair, so whether you’re in BC or just want to escape America for a bit, come to class and bring your most urgent and challenging questions about roasting.
I’m grateful to George and the team at Revolver for hosting the class. If you’ve never been to Revolver, it’s a treat: the rare third-wave shop that puts humans first and also makes wonderful coffee.
See this link here for tickets, and I hope to see you in Vancouver
Roasting Masterclass | Montreal (11/7)
Nov 04, 2018
I’m pleased to announce that I’ll be offering a three-hour roasting masterclass in Montreal on November 17. The masterclass will include two hours of lecture, a cupping of the Roast Defect Kit, and thirty minutes of Q&A. I personally guarantee that any roaster who attends will take home many new and useful roasting ideas to implement.
Tickets and information about the class are available here.
As many of you know, I founded Café Myriade in Montreal back in 2008. At the time, Myriade was incredibly innovative, and many of the systems I brought to Myriade became standard practice in cafes around the world. Some unfortunate incidents transpired a few years later, and I sold my share of the business. Montreal is a wonderful city, and I’ve missed it ever since.
On November 17, I’m not only offering the masterclass, but returning to the Montreal coffee scene as a partner with Andy Kyres (of Tunnel Espresso) in The Canadian Roasting Society, a new co-roasting facility. I believe CRS will impact roasting in Montreal the way Myriade once revolutionized the city’s café scene. We will offer roaster training, white-label roasting, and rental time on our fleet of Probat roasters.
After the masterclass, we’re holding several public events:
A cupping of Tunnel’s future roasting brand (name TBD)
An espresso lesson based on a demo of the Decent Espresso Machine
An espresso extraction contest using the Decent
A grand-opening celebration with music and drinks.
If you’re anywhere near Montreal on the 17th, we’d love to see you there.
Litmus Coffee Labs' First Product: The UFO Spray Head
Nov 02, 2018
For our first product, we’ve chosen to offer an upgraded spray head for the Curtis G3 and G4 batch brewers. Why did we choose the Curtis? The Curtis G4 Thermapro is the most capable batch brewer on the market, but its spray head is its proverbial Achilles heel, and we wanted to fix that.
Note the way the original Curtis spray head favors the grounds in the center of the bed. It may be difficult to tell from the photo, but the spent bed is much lower in the center and raised on the edges.
The G4 has the industry’s most versatile programming and user-friendly interface, and it performs more consistently than most batch brewers do. However, the spray head greatly favors the grounds near the center of the coffee bed (evidenced by the large, depressed area in the center of the spent coffee bed). The result is exceptionally uneven extraction, which yields more bitterness and astringency and lower overall extraction levels.
Our goal was to help the machine reach its full potential by improving the evenness of its extractions. Our device produces better and higher extractions by distributing water more evenly across the entire coffee bed.
Discover & share this Animated GIF with everyone you know. GIPHY is how you search, share, discover, and create GIFs.
Dozens of beta testers over the past few months have found our spray head yields a more uniform extraction as well as a higher extraction. That means your coffee will taste sweeter, less bitter, and less astringent. As a bonus, you'll be able to use a bit less coffee grounds to produce the same brew volume and brew strength. Our mighty little spray head will pay for itself many times over, in both quality and cost savings.
Thanks for reading. You can buy the UFO and Litmus Coffee Lab's other products here.
Last year, I met Dan Eils, an engineer, through my blog. We found we had a shared philosophy on how to go about improving coffee equipment, so we decided to set to work on a new coffee-machine project (which will take us approximately forever to complete). While working on the machine, I suggested we take on some bite-sized projects to fix some problems in coffee making, and hopefully those projects would make enough money to fund our R&D along the way. Thus was Litmus Coffee Labs born.
At Litmus we've got a few products in the pipeline, all designed to be affordable and to significantly improve your coffee. We’ve had dozens of beta testers using our products happily for several months, so we’ve decided we’re finally ready to launch our company. We will announce products on this blog, you can buy them HERE and we guarantee your satisfaction with all of our products. Feedback is always welcome.
If there are any common coffee-machine parts you think could use an upgrade, drop us a line here or at litmuscoffeelabs@gmail.com.
I’m rather overdue in noting that my books are available around the world in various languages. Whether you would like to read one of my books in French, Spanish, Russian, Czech, Hungarian, or Korean, please visit these links below to buy the translated editions. To resell my these translated editions, please use the same links to make wholesale inquiries. The books make great holiday gifts. Just saying. :0
One thing notably absent from most marketing and discussion of grinders is mention of extraction level. Manufacturers routinely reveal burr size, lbs or kg per hour, motor RPM, etc, but rarely mention extraction data. It would be a great service if the SCA or some other hypothetically impartial body would test and rate grinders and other coffee gear using objective metrics. In the case of grinders, the most important metric would be extraction level. (I know that grinders don’t do the extracting.)
Given that roast development affects extraction data, there probably cannot be a standardized, objective number (eg this grinder extracts a certain recipe at 20%). But it wouldn’t be impossible to use extraction data to compare grinders. For example, one could test the relative extraction levels numerous grinders yield using beans from the same roast batch.
A few facts about grinders, extraction, and coffee flavor:
Higher extractions are almost always better. For a given brew recipe and grinder, the highest extraction is not necessarily the best. For example, many of us have had the experience of setting the grind one small notch finer and having flavor deteriorate despite a marginally higher extraction level than that produced by the coarser setting. However, if you measure and taste hundreds of batches of a particular brewing method, the best brews would likely cluster around the highest extraction levels.
A technique that produces higher extractions for a particular brewing method will usually yield better results than will lower-yielding techniques. For instance, if you improve your puck prep to decrease channeling during espresso extraction, flavor improves and extractions increase.
If two grinders yield different average extraction levels for a given set of brewing parameters, the grinder that yields the higher extractions will almost always produce the tastier coffee.
As a grinder’s burrs dull with use, extraction levels will decrease.
Improving burr alignment will increase average extraction yield.**
**A top-notch grinder with poor alignment may produce higher extractions but inferior flavor compared to a mediocre grinder with excellent alignment. Many of us have had this experience with high-extraction, gushing, channeled espresso shots from an EK. A perfectly aligned EK can yield magical espresso, but few of us have had that experience.
You may not personally be a big fan of measuring extractions, but measurement offers many benefits, not the least of which is offering some objective data on which to base discussions and comparisons. Measurement led us out of the dark age of ristretto madness, measurement helped me to discover the value of the EK grinder (something about which even Mahlkonig was unaware), and measurement can help to evaluate puck-prep methods, burr sharpness, burr alignment, and of course, repeatability of results. Extraction measurement is a tool, not a dogma. Measurements offer valuable data, which you can use as you wish.
There are two important reasons to consider extraction levels when choosing a grinder:
A grinder that produces higher extraction levels will generally yield better-tasting coffee.
Higher extraction levels allow you to use less ground coffee to achieve the same brew strength and weight.
For example, let’s say you use an espresso grinder that typically yields 19% extractions and 9.5% TDS using 20g of grounds to pull 40g shots. If you then switch to a grinder that produces 22% extractions, you can then produce 40g shots with 9.5% TDS by using only 17.3g of grounds. (Please note these numbers are a little imprecise, but I’d rather not address here.) Decreasing the dose by 2.7 g per shot would add up to an annual savings of over 400 lbs (190 kg) per year for a café that pulls 200 shots per day. That means spending, say, an additional $1000 USD for a higher-yielding grinder may yield an annual return of $4000, assuming you are paying $10 per lb ($22 per kg) for beans.
The bottom line: better grind quality produces higher extractions, which result in tastier coffee and cost savings.
Please leave a comment below. I’d like to hear from you.
Custom Grinder | Photo Courtesy of Frank Durra @titusgrinding
I recently posted a roast curve on my IG to illustrate how the way one sets the axes (the ranges for time, temperature, and ROR) affects a curve’s appearance.
For instance, if one sets the ranges too high, a curve may look like this:
Note how the ROR curve is compressed into a tiny vertical space. Curve views like this one are quite common (and useless).
Minimizing the ranges of the axes expands the curves and provides a better view:
Red = Inlet Temp… Blue = Bean Temp ROR…Green = Environmental Temp
While this may seem obvious to many readers, I see a tremendous number of roasters, both in person and on Instagram, setting their graph axes more like the former than the latter. Such curve views will make a roaster overly confident in his or her results. Quality Control and progress will suffer.
A while back, I badgered the fine folks at Cropster to automatically adjust the axis ranges. While Cropster can’t do that during a roast, as it has no way of knowing what the necessary ranges will be, they listened and made the range-minimization automatic when viewing past roasts.
The same principle of optimizing the curve view applies to adjusting ROR smoothing (via the ROR interval in Cropster or the delta span in Artisan) and using appropriately responsive and well-located probes. These are fundamental — not advanced — concepts. Simply put, if you don’t practice all of them, you’re handicapping your roast-curve analysis for no good reason.
Going back to the Instagram post, many commenters volunteered opinions about how the coffee and the curve. I was surprised by many of the assumptions people made about what the operator had done or how aspects of the curve would affect the coffee’s flavor. (Hint: the timing of the turn is meaningless and if someone else’s turn is higher or lower than yours, it says nothing about flavor.)
Typing with one’s thumbs on Instagram is not an efficient way to have long conversations, so I thought I’d turn the discussion into a blog post. Some readers may not want to risk making mistakes publicly, but the only way to learn is to put yourself out there and have this discussion. If this conversation is productive and involves a diversity of commenters, perhaps this “game” will become a series. If that appeals to you, please participate.
So, what can (and can’t!) you glean from the curve below? Please, no questions about the coffee, machine, or curve; only answers. I’m intentionally not providing any more information than what you see below. There are no “tricks” involved — the machine, probe, coffee, batch size, between-batch protocol, etc, all fall within the realm of reasonable “best practices.” Thank you.
Red = Inlet Temp… Yellow = Environmental Temp… Blue = Bean Temp ROR
Common roasting machine problems
Sep 16, 2018
I’ve worked with several hundred roasting machines over my consulting career and have experienced a troubling problem: manufacturers often deliver roasting machines with what I would consider defects, and then refuse to acknowledge the problems or fix them for customers. I won’t name companies in this post, but would like to discuss a few of these recurring problems here in the hopes that roasting-machine manufacturers address these issues soon.
DRUM RPM
The most common inconsistency I have noticed in delivered machines has been drum-RPM count. There are two issues around drum RPMs and new machines: delivered machines having consistently suboptimal RPM levels, and delivered machines of a particular model from a given company having wildly different RPMs. I understand that manufacturers may disagree with me about appropriate RPM levels; that’s fine. But when I see a 1kg machine delivered with 50 RPM or a 12kg machine delivered with 35 RPM, or a 15kg machine delivered with 70 RPM, we’ve crossed the line from debatable to unreasonable.
In my seminars I often share this table of RPM recommendations. The numbers are merely estimates. Please don’t think that if I recommend 50—54 and your machine clocks in at 55 that you have a problem; you don’t. Please note that I cannot recommend a precise RPM level for all machines of a particular size because the proper RPM level depends on drum diameter, and two different models of 15kg machines, for instance, may have quite different drum diameters. For example, a 15kg Joper has an unusually long, small-diameter drum, while a Probat UG15 has an unusually shallow drum with a large diameter. All else being equal, the Joper’s drum RPM should be higher.
INCONSISTENT RPMs
It’s tempting to assume that machine manufacturers are all experts at roasting, but few are. For instance, one US manufacturer repeatedly tells customers that ROR crashes don’t matter, they confound baking with roasty-ness, and they seem to think that ROR flicks at the end of roasts are “normal” and not a problem. I, and every competent roaster I’ve ever worked with, couldn’t disagree more. The same company offers costly roasting classes, which should give readers pause. One decades-old machine manufacturer routinely delivers 12kg machines with drum RPM ranging from 35—55. Beyond the fact that 35 RPM is unreasonably low for a 12kg machine, this company must (I hope) have some RPM target, so why in the world are they willing to ship machines with such disparate RPM levels? That company has yet to agree to fix any of those 35-RPM machines and claims that 35 RPM on the 12kg machine is “normal” while also shipping some machines at 55 RPM. Contrast that with an experience I had this month with Reyes Tellez at Probat USA: I had just begun working with a new client on his Probat P12. I asked the client to fill out a consultation intake form, which included measuring the machine’s RPMs. It turns out the machine’s RPM was 67 instead of the 55 that both Reyes and I agreed was optimal. I emailed Reyes a video of the drum turning for one minute. A day later, Reyes acknowledged the problem, said he suspected there was a fault in the generator, and overnighted new generator to the client. That fixed the problem immediately. Every company makes mistakes or delivers machines with faults; that doesn’t bother me. It bothers me, and should concern everyone thinking of purchasing a roaster, when companies refuse to acknowledge or fix those faults.
OTHER FEATURES
Inconsistencies often exist with other roasting-machine features. For example, one major brand often delivers machines with excessively high airflow, several offer burners that are woefully underpowered for their intended batch sizes, and many manufacturers still provide temperature probes too slow to produce the quality of data necessary for expert-level roasting.
SOME COMPANIES ARE LISTENING
Whenever I get a new client with a poorly tuned machine, I ask him or her to tell the manufacturer. For years, the manufacturers would almost always respond by asserting their expertise and then dismiss the customers’ concerns. I’ve had the complete opposite experience with Mill City Roasters. Steve and his crew have not only added new features every year to their machines, but they have considered and tested every recommendation I have made, and they have implemented almost all of them. Although I have no financial relationship with Mill City (other than them selling my book and my buying a machine from them— at retail), I’ve enjoyed sharing my experience with them because it’s a joy to work with a company willing to listen, test, and improve continually.
I see it as part of my job as a consultant to ensure manufacturers get feedback from both myself and from clients, and to advise clients to buy from companies that are open to feedback and determined to improve. Through that process it has become easier to know which companies take responsibility for their products and for their customers’ satisfaction.
***
Thanks for reading. I respectfully request that comments not directly criticize any particular brands; let’s please focus on features and experiences, and not on brands or models.
POST-PUBLICATION NOTE: Some readers have expressed confusion about whether the RPM recommendations refer to batch sizes or machine capacity. For instance, they are wondering if a 7-kg batch in a 15-kg machine calls for the same RPM as that recommended for a 7-kg machine. The answer is no. To be clear, the RPM recommendations are based on machine size and drum diameter, not batch size. Whether it is beneficial to adjust up or down a few RPM when doing half batches is a separate discussion.
Advanced Mode on the DE1+: The Best Quality Espresso Extraction I've Ever Had
Jul 19, 2018
Decent Espresso DE1+ Machine
Advanced Mode on the DE1+ is perhaps the deepest rabbit hole into which any barista can climb. I generally recommend baristas master the machine in the more familiar Pressure Mode first, and then get comfortable with Flow Mode before using Advanced Mode. Once I dove into Advanced Mode, no other mode or espresso machine could ever satisfy. The possibilities are endless.
Advanced Mode on the DE1+ allows the barista to customize a recipe in any way he or she desires. Would you like to preinfuse with a set flow rate, switch to controlling the shot based on pressure, and then switch back to flow mode? No problem. If you want to then use a different brewing temperature for each stage, that’s easy. You can set “triggers” that tell the machine to move from one phase to the next based on pressure, water volume, or time. Advanced Mode is incredibly versatile, and it’s much easier to use than I had expected when John first told me about it. Recipes can be as simple or as complex as you would like.
My favorite type of espresso shot to pull in Advanced Mode mimics filter brewing: after pre infusion I program a pause, or “bloom”, to allow water to saturate the entire puck before turning the flow back on. This type of recipe increases extraction by 1%—1.5% and greatly improves evenness of extraction because preinfusion alone does not fully saturate the grounds. Pausing after preinfusion increases extraction while reducing astringency and bitterness, which is the biggest win-win I can imagine in espresso extraction. Blooming also does more than any other method to bring the quality of espresso extraction closer to that of filter. (Yes, filter extraction quality is higher than that of espresso.)
Below are the recipe screens from a recent shot I made at home, ground in a Baratza Forté. Extraction (with 0 for VST presets--as always--for those keeping score at home) was 24% (the default presets likely would have brought that up to 24.5%), and TDS was 8.5%. The beans were four weeks old, which boosted extraction a bit. The final screen is the resulting curve. Take it in slowly. It's not complicated, but having so many new data points to look at can be daunting for a moment.
WELCOME TO NEW YORK'S NEWEST SHARED ROASTING SPACE
Jul 12, 2018
Last year I had plans to open a cooperative roastery in LA but various problems with the landlord and the building forced me to cancel that project, I'm sorry to say. However, I've been quietly involved in a similar project in NYC and it is now open for business.
I'd like to introduce Regalia Company, a boutique roastery and shared roasting space. I've teamed up with my friend Paolo Maliksi to open Regalia and to fill a need in NYC. Sure, there are other places where you can rent time on a roaster, but Regalia offers a few unique features you won't find anywhere else. Regalia is just one subway stop from Manhattan and straddles the border of Queens and Brooklyn. At Regalia we offer discounted rates to roast on our 15kg Mill City roaster, perhaps the most customized, feature-laden roaster on the market.
At Regalia you're welcome to store your own green coffee or buy some green from us (we have ample storage). If you're new to roasting and want some coaching, Paolo is available to help at no charge. Once clients are up and running at Regalia, I'm available as a resource, offering free coaching and consulting to our partners.
Among other features at Regalia, we offer a fully-stocked lab with an EK grinder, cupping supplies, vacuum-sealing machine, DE1PRO espresso machine, and Fetco batch brewer. As well, I'll be at Regalia a couple of times per year to offer classes, tastings, and coaching for clients.
Whether you have a café in NYC and would like to save some money and support your own brand, or whether you just want to roast coffee for clients, we'll work with you and support you in any way we can.
Probably the most exciting feature of the DE1+ is its ability to manage shots by flow rate. That may not sound like a big deal, but read on to have your mind blown.
The flow mode recipe screen. It's simple and intuitive.
Most espresso machines apply a steady amount of force to the coffee puck, the puck provides resistance, and the resulting flow rate rises as the puck erodes due to extraction. In my experience, this dynamic leads to erratic flow paths late in a shot, regardless of the quality of the barista’s puck prep. Uneven flow through a puck is akin to lots of mini channels, and, like larger, more obvious channels, it decreases extraction and increases bitterness and astringency.
Pressure profiling machines allow the barista to vary the pump’s applied pressure. The classic, competent pressure profile I had written about in my ebook Espresso Extraction: Measurement and Mastery was inspired by the profile of a lever machine, and includes preinfusion and a pressure ramp followed by a pressure decline. The pressure decline in the latter half of a shot can prevent the flow rate from rising as the puck erodes. With such a pressure profile, if the grind setting and puck prep are skillfully executed, the result will be a relatively constant flow rate and minimal channeling.
In flow mode on the DE1+, the machine manages the output (flow), not the input (pressure), which is a big step forward for repeatability. It does this by varying the pressure up 6,000 times per second (not a misprint) to trace a programmed flow curve. Flow mode takes the pressure (sorry) off the barista to provide the perfect puck prep and grind setting. Don’t get me wrong: skilled puck prep and setting the proper grind are still important. But pulling shots in flow mode compensates somewhat for imperfect puck prep and grind setting.
DE1+ screen view showing the pressure, flow, and temperature curves of a flow-profiled shot.
How is that possible? In flow mode the DE1+ “fixes” channels. That may seem too good to be true, so let me explain. When a typical espresso machine’s pump delivers constant pressure and a channel forms, the puck’s resistance decreases. A channel allows higher flow as lots of water bypasses the more densely packed areas of the puck. The extra flow through the channel causes it to enlarge, setting off a vicious cycle of lower resistance causing higher flow and a larger channel, leading to even less resistance. When a channel forms in flow mode on the DE1+, the pump slows in order to maintain the desired flow rate, and therefore doesn’t exploit the channel as aggressively. We have found that as the pump pressure decreases in flow mode, the grounds rearrange themselves, decreasing the size of the channel. As grounds shift into the channel, it shrinks, the puck’s resistance rises, and the pump pressure increases again to maintain flow.
Flow mode may not improve a great barista’s best shots (though it probably will), but it improves the majority of shots, even by good baristas, and can dramatically improve the quality of shots pulled by average and poor baristas. I see flow mode as an incredible tool for restaurants and chain coffee shops where baristas may not be as skilled as those at the better third-wave shops.
A flow shot with the grind too coarse in a mediocre home espresso grinder. Note how the pressure curve (the green line) peaked at only 3.5 bar. That implies the grind was too coarse, but the DE1+ prevented the shot from gushing and running too fast.
Although I think flow mode is an incredible advance, it can be a crutch, and like any crutch, it will be up to the barista to not rely on it excessively. For example, if a barista creates a flow profile, aims for a 20g in/ 40g out/ 30-second shot, and sets the grind five notches too coarse on a Robur, the shot will take approximately 30 seconds and the extraction will be low. However, the result will be superior to the 10-second “gusher” that such a grind would create in pressure mode or on a standard “dumb” espresso machine. The gusher will also extract too low but will have far more channeling, bitterness, and astringency than the shot pulled in flow mode. To distill the difference down to one critical point, the flow shot will extract much more evenly than the pressure shot.
Mind blown.
Pressure Profiling on the Decent Espresso Machine
Jun 07, 2018
I've had a DE1+ at my house for the past few weeks and I've already learned a ton. In this post, I'd like to introduce readers to the "pressure" and "flow" modes of the Decent. In the next installment we'll discuss the "Advanced" mode and I'll introduce some new ideas about espresso extraction that I've learned from the machine.
The DE1+ comes with a tablet computer and quite a few sensors. There are so many sensors that the sensors are literally monitoring each other to ensure they are as precise as possible. Instead of a boiler the DE1+ has a "thermocoil", or continuous water heater (the De1+'s temperature profiling would be impossible with a traditional boiler), the machine measures temperature just above the shower screen (not at the boiler, a major improvement), and it mixes hot and cold water continually to maintain precise water temperature at the screen. The steam runs extra hot in order to squeeze the most juice possible out of standard home electricity. On the tablet you can program the hot water tap to dispense water at any chosen volume and temperature. Within five minutes of turning it on in the morning, the machine is ready to make coffee at a precise temperature -- no sink shots required. When using a bluetooth scale, the DE1+ can stop shots gravimetrically.
Any one of those features would probably cause the professional coffee community to get excited about the machine. But none of those innovations are what makes the Decent the best espresso machine in the world. What's amazing is that it can brew espresso using pressure profiling, flow profiling, or a combination, and the barista can see the pressure, flow, and temperature curves in real time during a shot. The feedback provided by those curves is invaluable. It's like Cropster for espresso, and once you see it, you'll never want to pull a shot without it. After pulling hundreds of thousands of shots over more than two decades and learning quite a bit along the way, I've probably learned more about espresso extraction in the past few weeks than I had learned in the past ten years.
The pressure mode is somewhat like that of other machines that offer pressure profiling, but the DE1+ allows the barista to see the results of his or her efforts and adjust accordingly. Given that we can taste only so many espressos per day, one can progress only so quickly by pulling shots, tasting, adjusting, and repeating. With the Decent, it's obvious which shots are worth tasting, which need a finer or coarser grind, and how much each shot channeled. That means I can dial in a shot nearly perfectly before bothering to taste it. My palate is grateful for the assist.
Programming in pressure mode is simple and Intuitive. You can program preinfusion to end based on a particular time or pressure target. Contrary to popular belief and what other machines' pressure gauges indicate, one does not preinfuse at a particular pressure. This is because no matter how hard the pump works, the puck must provide back pressure before the system is pressurized. Preinfusion works at atmospheric pressure until the headspace above the grounds is full of water, then pressure ramps up as the grounds absorb water, swell, and provide increasing amounts of back pressure.
In the example below, I have asked the machine to preinfuse at a flow rate of 4 ml/s until 15 seconds has elapsed or the pressure reaches 6 bar. As soon as one of those goals is met, the machine moves on to the "rise and hold" phase, in which I've asked it to rise to 8.2 bar and hold that pressure for 10 seconds. Next the machine will lower down the pressure to 5 bar over 30 seconds.
Pressure mode recipe screen
Below is the resulting shot.
The green line is the pressure curve and the blue line is the flow curve. The curves offer a treasure trove of insights:
The volatility in the green curve indicates channeling (note the channel near the top/right of the red circle.) The volatility of the pressure curves on the DE1+ come from two main sources, as far as I can tell: clumped grounds and poor puck prep. In this case, I'm using a grinder that is producing an incredible amount of clumps. The grinder hasn't been aligned or fully seasoned and I'm hoping that I can improve the grind quality soon and the volatility will decrease. Bigger, better, sharper burrs generally produce smoother curves-- that's obvious when I pull shots from two different grinders. As a side note, one remarkable thing about the Decent is that in flow mode it "fixes" channels. More on that in the next post.
The blue curve shows that the flow rate dipped after preinfusion and took a long time to level off. This is what John refers to as a "slow-to-develop shot." We think this happens due a combination of possible reasons: the grind is too fine, the puck is too compressed (more on this in a later post), or the puck is still absorbing water during the 15--20 seconds after preinfusion ended because preinfusion didn't fully saturate the puck. We have generally preferred espressos that didn't have such a dip in flow rate, and we're still working on the significance of this. Speculations are welcome. (For the record, we have preferred shots where the flow is steady almost immediately after preinfusion.)
June 23 Roasting Masterclass, Amsterdam
Jun 03, 2018
Sample slide from class of a suggested, generic starting point for settings when approaching an unfamiliar machine and coffee.
It's a bit last minute, but I hope if you're in Amsterdam for World of Coffee that you'll join my Roasting Masterclass on June 23, 8:30am--11:30am. The class will be located conveniently between the city center and RAI Amsterdam, where WOC will be held.
If you're a roaster, I strongly recommend you consider attending. Many roasters are skeptical before coming to one of my masterclasses, but almost always leave feeling excited to have many new ideas with which o experiment in their roasting. This class will challenge you, and I guarantee you will be satisfied. I'm always thrilled with how many attendees return to repeat the class in later years to see what new ideas they can pick up.
There will be plenty of time to ask questions, so bring your toughest and most pressing questions. The Q&A is always vibrant, the roast samples at class will be just like those of the "Roast Defect Kit" I've released today, and I promise to leave you with a lot to think about.
Please see the Eventbrite link HERE for more details and to purchase tickets (€225)
See you in Amsterdam.
Photo Credit: Liz Clayton
Roast Defect Kit #2
Jun 03, 2018
I'm pleased to announce that I've just released the second ROAST DEFECT KIT today, in conjunction with Regalia Company. We were waiting for Regalia to receive some lovely new-crop Kenya AA from the Karumandi Factory in Kirinyaga. Paolo gave it a few practice batches and then nailed the "good," "baked," and "underdeveloped" roasts. I tasted them blindly this morning and am proud to offer these to readers.
I developed the idea of the RDK while writing The Coffee Roaster's Companion, as a means to help coffee enthusiasts identify baked and underdeveloped roasts, as well as to offer an example of an excellent roast. Being you able to identify underdevelopment and baking is a skill even most coffee pros lack. Some coffee drinkers may be so accustomed to baking or underdevelopment that they have come to enjoy it. To each his or her own, of course. But whatever your preference, I think there is still value in establishing what the terms mean and how to recognize them in the cup.
My hope is that you'll blindly taste the samples in the kit with friends and colleagues, discuss what you taste, and the compare the cup results with the roast curves. There should be enough coffee in each sample to repeat the tasting session several times.
In the RDK we've included:
3x 100g frozen and vacuum-sealed roasts: an under-developed roast, a baked roast, and an excellent roast. When we fulfill your order, we'll send you the roast curves and their respective settings.
2x small packets of mineral salts (CaCl, MgCl, KHCO3). Each packet willconvert four liters of distilled (demineralized) water into perfect brewing water. We've included these to help everyone who tries the RDK to have a more similar taste experience.
Below are the roast curves; please note that although one can objectively identify a baked roast by looking at its curve (if derived from valid data), it is impossible to identify underdevelopment merely by looking at a roast curve. That is because curve data are derived from surface bean-temperature readings, but underdevelopment refers to undercooked bean centers. At this time we have no way to accurately measure or infer the temperature of the bean centers during roasting.
Please click HERE to purchase the RDK. We have only twenty kits available on a first-come, first-serve basis.
UPDATE: ALL OF THE RDKs HAVE ALREADY SOLD OUT IN JUST THE FIRST DAY. WE'RE A LITTLE SURPRISED, AND WE'LL WORK ON THE NEXT ON TOUT DE SUITE. IF YOU'D LIKE TO BE ON THE WAITING LIST FOR RDK #3, PLEASE SEND AN EMAIL TO hello@regaliacompany.com AND WE'LL LET YOU KNOW WHEN THE NEXT ONE IS READY. THANKS FOR THE SUPPORT!!
The "good" batch
Underdeveloped
Baked
How a Strong Offering Philosophy Beats “Purchasing Power”
May 24, 2018
A sentiment I hear often from buyers representing smaller roasteries is, “How can I compete with bigger buyers for the best green coffee? They have all the purchasing power!”
I’ve been at both the small (Ritual, Tonx) and the big (Stumptown, Blue Bottle, Peet’s) and I ask: How can they compete with you, small buyer? I have never encountered a more thoughtful buyer than the one who can purchase only a handful of coffees a year. A big buyer has to deal with a persistently huge appetite, and if you recall the times you’ve been famished, your discernment for quality tends to dip. It’s when you can’t eat too much that you become very, very picky.
Besides, “best” is a fairly useless term when considering what guides your green coffee purchases. As I discuss in Dear Coffee Buyer: A Guide to Sourcing Green Coffee: “Coffee buying is not a skill with linear, inevitable results, where two hypothetically “equal” buyers choose to buy the same coffee. Scores may be objective, but preference is not. A world with more proficient buyers is a world with greater availability of excellent, varied, coffee options.”
The most important thing that a buyer of any size can do is to establish an offering philosophy, something I cover in greater detail in the book:
When I began in specialty coffee there were two implicit but well-followed rules:
• You must offer representative coffees from the three major growing regions: Latin America, East Africa, and the Pacific Islands.
• You must offer a fistful of proprietary blends.
To this day, you can still see many of these rules followed in older establishments such as Peet’s and Starbucks. It seems wild now, but the third-wave pioneers mostly accepted these rules, with the slight tweak of replacing “representative” with “most pleasing” or something like that. A menu of thirty-one flavors was predictable and honestly represented the world’s spectrum of coffees. A roasting company distinguished itself almost entirely by the way it talked about coffee’s flavors, as expressed by some combination of national terroir and roast degree. By today’s standards, almost all roasters had a heavy foot on the gas pedal of the roaster. Those dark roasts and discussions of flavors, plus each company’s coffee-shop aesthetics, comprised the heart of the “brand.” It’s not that roasters felt they had no choice in this matter; it’s more that the idea of choice was precluded by these implicit rules.
A few optional origins produced exceptional quality at entirely reasonable prices. Some of the origins that were overpriced from a cup-quality:cost perspective, such as Hawaii and Jamaica, were nearly ubiquitous at the specialty cafés of the second wave. As late as 2010–2011, Kevin Knox, ex-buyer at Allegro and coffee-buying luminary, complained about roasters that weren’t offering the full lineup, nearly implying that it was a cheat (whether to customer expectations or to implicit rules, I am not sure) to exclude naturals or wet-hulled coffees from your menu.
Because I learned to buy coffee with no mentor and few understood expectations, I modeled the early menu at Ritual in 2007 in the same way that I saw Stumptown and Intelligentsia doing it, which is to say that I bought at least one coffee from every region and offered it nearly year round. Those two companies were pioneers of the third wave, and it seemed reasonable for me to first copy what they did, as their practices were the closest things to “instructions” I could find.
I broke the rules by accident initially, but as soon as I did, it was an epiphany. I had been traveling for weeks and miscalculated our consumption of Sumatra against our inventory, causing our roastery to run out. Sumatra was a staple of every third- wave menu at the time. I began going through the motions of replacing it. I contacted several brokers—traders who buy and sell coffee of various qualities—and asked for Sumatra spot samples (samples representing lots that are in domestic warehouses and available for immediate shipment to a roastery), roasted and cupped the samples, hemmed and hawed over the results, and finally made a decision: Ritual would no longer buy Sumatra.
By 2008, Ritual was building a reputation for clean, acidic coffees. I loved exotic flavors, but I wanted them to be true to the bean, not the result of zealous roasting or overwrought processing. At the time, if you had given a cup of Sumatra—a region that produces predominantly wet-hulled coffee—to a coffee taster and told her it was from Latin America, she’d have told you it lacked clarity of cup if she was diplomatic, or that it was dirty or defective if she was honest. If you then said, “Oops! I’m mistaken, it’s from Sumatra,” the coffee taster would recant and suddenly begin extolling the cup’s earthy, woody, dry characteristics. To me, the idea that different origins should be judged differently is foolish. How could I ever look at a Latin American producer again and tell him his coffee wasn’t up to snuff because it was earthy, woody or dry, while I was buying earthy, woody, dry coffee from Sumatra?
I couldn’t.
Instead of arranging for purchase of Sumatra, I talked with Ritual’s owner, Eileen, and convinced her that it was OK for us to not offer Sumatra. She asked me a few due diligence–type questions and then smiled and, with her ever-persistent entrepreneurial spirit, championed the decision. I afterwards heard her bragging about our decision to not offer Sumatra because it wasn’t up to the quality standards we had established. I was relieved that she was in agreement with me, thrilled that she was now using our decision to promote our green coffee narrative, and over the moon that I could—for a time—stop tasting wet-hulled coffee samples.
Now, the point of this story is not to tell you what your offering philosophy should be, though I’d selfishly be pleased if you stopped roasting wet-hulled and most naturally processed coffees. I want to make clear that you should have an offering philosophy, and you’ll be best off if it reflects your own taste preferences. The decision to stop offering wet-hulled coffees was a revelation for us at Ritual, and it felt like a huge weight was removed from our shoulders. I imagine that at this point not offering wet- hulled coffee is so deeply imbued in the ethos of Ritual that there would have to be a true revolution in wet-hulling for them to reverse course and begin offering it again.
The real revelation was not that we no longer had to offer Sumatra; it was that we didn’t have to follow any of the unwritten rules. Furthermore, your personal tastes do not have to be as simple as what flavors you favor in brewed coffee; they can also reflect more abstract preferences.
If you’re inclined to note that the grass is always greener on the other side, gaze on. It’s true! Bigger buyers absolutely have advantages, but so do you. Yes, they have purchasing power, and for many suppliers, it’s easier to work with fewer, bigger buyers. Bigger buyers also tend to have more satisfactory outlets for the few lots that don’t show up as expected. But step outside of your coffee head for a moment and ask yourself if your most memorable experiences, culinary or otherwise, come from the bigger or smaller brands.
Pick up a copy of Dear Coffee Buyer for more of Ryan's perspective and advice on green-coffee buying.
Dear Coffee Buyer
May 06, 2018
About five years ago, I began pestering my friend Ryan Brown to write a book about green-coffee buying. I thought Ryan was the perfect person to write such a book, as he was the most competent coffee buyer I'd ever encountered. It took those five years, but last year Ryan finally gave in and wrote the book. I'm pleased to say it's a masterpiece.
My first memory of cupping with Ryan took place in the basement of Ritual Coffee in the mid-2000s. Ryan had about ten coffees set up blindly on the table, brought his nose no closer than six inches (15cm) to each cup, and correctly declared which coffee was in each cup (mind you, many of the coffees were quite similar.) I was amazed; Ryan could probably out-sniff my sister’s beagle, and his green evaluation seemed borderline psychic compared to my ordinary abilities. My first thought upon witnessing that trick was that I was going to keep this guy around for a long time and learn what I could from him.
Happily, the rest of the world can now also learn from Ryan. Dear Coffee Buyer is like Ryan’s doctorate-level thesis on green coffee buying. The book is part masterclass in green evaluation, part clever advice for professional green buyers and those thinking about getting into the business, part travel narrative, and part editorial of what terms like “direct trade” really mean. I hope every barista, roaster, and green buyer reads this book. If they do, the industry will be much better for it.
We're also offering a poster derived from one of the book's gorgeous illustrations by Jory Felice. The poster depicts the various stages of the major coffee-processing methods. Please see below for the poster and sample pages from the book.
Ryan and I are jointly selling the book and poster here
We're offering a $10 discount if you buy the poster and book together as a bundle. If you are interested in placing a wholesale order for 10 or more books or posters, please contact me directly at scott@scottrao.com
Coffee-processing poster. Great educational wall art for any café or roastery.
The Virtual, Advanced Roasting Class, Available Until MAY 21
Apr 24, 2018
UPDATE APRIL 21: The Seattle classes have passed, but the virtual class will be available until May 21. If you purchase the virtual class you'll be able to view it as many times as you'd like until May 21. Virtual attendees will receive an email linking to the class slides and will be welcome to participate in a Facebook group to discuss matters related to the class. I'll participate in that group daily.
Below are some sample slides from the class. See you at the Facebook discussion!
Introducing the Roast Development Kit + Virtual Roasting Class
Apr 06, 2018
First, please let me apologize for taking so long to offer the “Roast Development Kit” I had promised in The Coffee Roaster’s Companion. It’s finally here, and I am certain it is going to have a beneficial influence on roasters’ understanding of coffee defects.
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Among the classes I’ll offer in Seattle this April is a roasting masterclass that will be offered to attendees both in person and virtual. In January I offered a wildly successful “beginners'” roasting class (which was much more advanced than any industry class) in conjunction with Map It Forward. For those of you who have never attended such a class, I’d like to explain a bit about them.
First, let’s get the bad stuff out of the way: the class in January was the first virtual class I’ve offered, and the feedback was overwhelmingly positive, but there are a few things I intend to improve this time around. The video and sound quality were good enough to communicate the lesson well, but not up to the standards of some virtual attendees who worked in the audio and video industries. I take feedback seriously, so the production quality of this next class will be better. Based on requests from previous attendees, I will also email the key slides from the masterclass to viewers ahead of the scheduled class date. Virtual attendees will have access to the class video for three weeks after it airs.
I’m also launching the Roast Development Kit (RDK) in conjunction with the virtual masterclass. Those buying virtual tickets will pay $50 less per ticket than live attendees to compensate for not having access to the tasting or being able to ask questions in person. However, virtual attendees will have the option to purchase the set of roast samples I’ll use in the class, in the form of the RDK ($50) that I had mentioned in The Coffee Roaster’s Companion.
I’m pleased to announce that The Regalia Company, a new roaster in New York City, will roast the samples for the kit. I co-own Regalia with my friend Paolo Maliksi and his wife Chisato (aka the secret weapon). From a distance I have been training Paolo to roast for the past several months through email, FaceTime video, Cropster screen sharing, and exchanging roast samples. I’m proud to say that Paolo, an accomplished cellist, is a diligent and disciplined student, and he is now one of the most consistently good roasters in the country. Some of the best roasts I’ve tasted in the past year came from Paolo, and he is dedicated to offering light, developed, consistently great roasts. I don’t even complain when Paolo offers naturals and honeys. :0 Paolo is the only roaster out there whom I would entrust to roast the samples for the (RDK) and my class, now that he has mastered the art of knowing how to judge, avoid, and create both baked and underdeveloped roasts. For those of you in NYC, Regalia is also currently renting time on its 15kg Mill City roasting machine. Please contact Regalia directly for more information.
The first RDK will consist of three frozen and vacuum-sealed 100g roast samples: an underdeveloped roast, a baked roast, and an excellent roast, all of the same coffee. With the kit we will provide the roast curves, complete with settings used as well as some notes about the coffee and roasts. We’ll also provide two small packets of mineral salts (magnesium sulfate and sodium bicarbonate), with each packet designed to convert four liters of distilled (demineralized) water into perfect brewing water. Importantly, using that water means that everyone in the world who tastes the coffees in the kit will be using the same water. Those buying the kit and following my grind and extraction recommendations should have a very similar tasting experience to that of the live-class attendees.
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As of April 30 Regalia will be offering the RDK to the general public on a regular basis. Going forward, each month we will offer a new RDK using a different coffee, and we may expand the kit at some point to include coffees with other intentional roast defects as well as various green defects. I also have hopes of using the kit to showcase the flavor impact of novel processing methods, such as those used by Lucia Solis.
Please click here to purchase tickets to the virtual roasting masterclass and Roast Development Kit
Thanks for reading.
Roasting Masterclass | Seattle
Mar 18, 2018
After last year's sold-out, fantastic roasting masterclasses in Seattle, I'm excited to offer an even better set of classes this year. The classes will again be held at The Lab at Ada's Technical Books in the lovely Capitol Hill neighborhood. There will be three classes:
UPDATE APRIL 21: The Seattle classes have passed, but the virtual class will be available until May 21; if you purchase the virtual class you'll be able to view it as many times as you'd like until May 21. Virtual attendees will receive an email linking to the class slides and will be welcome to participate in a Facebook group to discuss matters related to the class. I'll participate in that group daily.
The links contain full class descriptions. But let me say here that the main topic will be a new system designed to prevent ROR crashes. I've worked hard with clients over the past year to figure out what causes an ROR crash and how to prevent it. Once you master the lesson in this class, you'll feel much more in control of your RORs at first crack.
Saturday's class will also be offered virtually, through a private Facebook group. Please see the details on Friday's class page. Virtual attendees will have the option to pay a lower ticket price OR receive in the mail the roasted samples that we will be using in the class, along with a water salts concentrate, so you can cup the same coffees along at home as we taste them in the class. Virtual attendees will have access to the class video for three weeks after it airs. Please note: in-person attendees will not have access to the FB group or video.
I have no doubt tickets to all three classes will sell out, so please don't wait. See you there!
It's Time to Create a Scoring System For Roast Quality
Mar 18, 2018
Coffee Roaster Controls
Coffee professionals almost universally use a 100-point scoring system to evaluate green coffee. The system is silly in some ways; for instance, in specialty it’s really a 20-point system, and realistically, readers of this blog probably drink coffees in the 82-90 point range 90% of the time. So if you taste a cup of specialty coffee and it’s “great” you could probably assume it’s in the 88-90 range; “good” puts you in the 85-87 range; and “meh” puts you in the range of 82-84.
Many of us have had the experience of filling out a standard SCA scoring sheet while cupping, and finding that our cumulative scores are much lower than what most pros would rate the coffee (and always lower than what the broker selling the green claims it is. Hehe.) That’s because, in a sense, the sheet is designed to nudge you toward conformity, usually in the mid-80s. It’s also because the quality of a coffee is not merely the sum of its parts in whatever way the form weights those parts.
The first time I scored a bunch of coffees on a form, I was a judge in the 2008 Best of Panama, which used a version of the SCA form. I had a working mental model of how scores like 82, 86, and 90 tasted, but I had never before needed to derive the total scores by adding the scores of individual attributes. I began by evaluating the fragrance, aroma, and sweetness, penalized points for defects, and ended up with a score that didn’t at all sound right. This was a nice, clean, and sweet coffee: 79. This coffee was all right; it seemed a little inconsistent and the acidity fell apart as it cooled: 87. I furiously found places to push the numbers up or down to more accurately land on what seemed to be a fitting score. It involved a lot of erasing and arithmetic.
The second time I scored a bunch of coffees on a form, I was a judge in the 2008 El Salvador CoE, where I did the opposite. The CoE form has eight scoring categories of 8 points each. (A coffee begins with 36 points, provided there are no defective cups in the sample.) Starting with the final score, I then frantically figured out what attributes added up to that number. It was better, but my scoring still involved some unpleasant fudging.
I eventually hit my stride on forms. I found what the average score for each component would be to yield an 86, which, throughout my coffee buying time, was a sort of benchmark. I then asked myself, for each attribute, is this an 86-like sweetness? Higher? Lower? Is this an 86-like acidity? An 86-like body? Et cetera. This worked surprisingly well, and I only ever found my final score to be at most about a half-point different from my initial gut reaction.
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I don’t want to dwell on the quirks or limitations of the industry’s standard scoring forms; they serve their purpose well enough, and coffee professionals seem, as a group, to have figured out how to agree on green-coffee scores. However, roasters and baristas often use these sheets to evaluate production roasts, a purpose for which the forms are not intended or well-designed.
Around the same time Ryan was judging the Best of Panama coffees, I had my first significant revelation about cupping forms and evaluating roasts. I was, coincidentally, at a “Best of Panama” cupping hosted by a roastery in Seattle, and I was having difficulty rating some cups because the sample roasts were all over the map. Some roasts were spot on, some terribly baked, and some underdeveloped. Being someone more tuned into roast quality than green quality, these roasts threw me. Others in the room were doing a better job of “seeing through” the roasts but I was also pretty sure some of their scores were being influenced by roast quality in ways they did not realize.
I have no doubt that great — and terrible — roasts sway professionals by 1-2 points here and there. I don’t mean to confuse a point that Ryan made to me after he read an earlier draft of this post:
When it comes to buying green, a coffee’s “true” cupping score should be the best one you can achieve with it at a given point in time.
I would argue, and I think Ryan would agree, that the influence of extraction, water, and roasting can only deduct from a coffee’s “true” score. That said, there’s no way to know with certainty when the extraction, water, roasting, etc, have all been optimized to help illuminate a coffee’s true score.
For example, that massively sweet fruit bomb on the table may get a score of 86 instead of 88 if the sample roast is very baked, because baking kills sweetness. The sample that retained its acidity and sweetness as the cup cooled may not be better than its neighbor that “fell apart” after cooling; the second cup may have simply been baked. “Brothy” underdeveloped roasts often don’t bring out the plump, pleasing, and juicy notes that some coffees potentially offer. Finally, I’ve had brews that tasted minerally, metallic, or gamey when made with water unsuitable for coffee extraction.
Regardless of one’s views on how much roast quality sways professionals in green evaluation (and to be clear, we’re all swayed to different degrees), it’s clear we’d be better off with a separate system for evaluating roasts if we want to get better at roasting and also want to avoid allowing roast quality to interfere with green evaluation.
Let’s say you production-roast a 90-point Kenya and the ROR crashes hard and then flicks. The coffee may still have some pleasant fruit since, after all, the coffee’s raw material was so stellar that you’d have to roast the coffee on a BBQ to destroy all of its goodness. You may score a cup from that roast as an 88. Now let’s say you execute a flawless roast of an 83-point blend component; you will likely still score that coffee an 83. As a production roaster, there isn’t much to learn from the Kenya scoring five points higher than the blend component. After all, you were handed two radically different types of raw material, did a masterful job with one of them, and a poor job with the other, yet the better job scored lower.
If you’ve read my two previous posts about seeing through roasts, part 1 and part 2 you’re familiar with my opinion that some cup traits are primarily due to roast, some are due to green quality, and most are a combination of the two. “Seeing through roasts” is more art than science. I propose that an effective roast-scoring system focus only on traits that are predominantly indicative of roast quality.
To that end, here’s a first draft of a proposed roast-scoring system.
A Scoring System for Roast Quality
Development (as in “how well developed are the bean cores,” not “how dark is the roast”): -2 to 0
-2: objectively underdeveloped -1: debatably underdeveloped 0: adequately developed (according to your standards)
Success in highlighting terroir or other roast goals: -2 to 0
-2: failure to highlight desired flavors -1: partial success 0: complete success in highlighting terroir, etc.
Baked: -2 to 0
-2: definitely baked, hollow, lost most sweetness -1: a little baked but still kinda sweet 0: not baked at all
Roasty: (not a real word): -2 to 0
-2: reminds you of your last cup of Starbucks -1: hint of char, smoke, or unintended roastyness (also not a word) 0: would please George Howell
Admittedly, you may find it awkward that scores will usually be negative, or at best zero. I’m personally okay with that, in the sense that roasting isn’t capable of improving green coffee. A roast will either show a coffee’s full potential (the score would be zero) or cause the coffee to fall short of its potential (the score would be negative.) As Ryan wrote in DCB:
“No matter what wizardry your roasting team is capable of, there's no way to improve a coffee's potential through roasting. Green coffee either has it or it doesn't.”
Please note that it would not be a good idea to subtract a coffee’s roasting score from its green score, as that will cause confusion and misses the point about keeping the green and roast evaluations separate.
Applying this Coffee Roast Quality System
Coffee #1: fast roast, no ROR crash or flick, tastes green Very underdeveloped (brothy): -2 Some varietal character shines through: -1 Not baked at all: 0 Not roasty at all: 0
Total Score: -3
Coffee #2: developed, but the ROR crashed hard and flicked Development is great: 0 Terroir shines through a little: -1 Very baked: -2 Very roasty: -2
Total Score: -5
Coffee #3: almost perfect, but development was borderline Development: -1 Terroir: 0 Baked: 0 Roasty: 0
Total Score: -1
I’d like to be clear that this proposal is a work in progress, and I hope readers will criticize this post constructively, and offer their own suggestions for improving the system.
Green coffee bean storage. photo credit: Liz Clayton
My apologies to the 150 or so readers who wrote to me requesting samples of coffees processed by Lucia Solis. Bad luck and timing have conspired to delay the availability of a suitable set of samples. Let me explain.
The first time I tasted a coffee processed by Lucia and her pet yeast, I was blown away. The coffee was a Rwandan and it was probably the best cup of Rwandan I've ever tasted. I immediately wanted more, and I told Lucia I wanted to be able to offer that coffee to my readers.
That coffee had already been spoken for, and Lucia and I hatched a plan to offer an Guatemala from a farm she was on her way to work at early this winter. The crop was delayed, and Lucia couldn't be there personally for the fermentation, so we passed on that one. Lucia's subsequent jobs all involved helping farmers turn low scoring coffees (78 ish) into more respectable offerings (84). Although it would be insightful to be able to offer and taste pairings of the Lucia- and non-Lucia- versions of those beans, I have been hesitant to offer anything below an 87. I've made that decision in part because I want readers to thoroughly enjoy the coffee, and also because in my experience, too many people will taste an 83-point coffee alongside its former 79-point self, and simply walk away far less impressed than they should have been, because neither coffee was insanely delicious.
The bottom line is that sooner or later, there will be a Lucia project suitable for this blog's readers, and when that happens, I'll reach out to all of you who have patiently waited for these offerings.
Thanks
Scott and Lucia.
Lucia Solis Classes in Seattle, April 19--21
Mar 09, 2018
This April, I'll be sharing the back building at the charming Ada's Technical Books in Seattle with my friends Lee Safar of Map It Foward and Lucia Solis of Solis Coffee Solutions. We'll all be offering various classes there. I'll be co-hosting one of Lee's classes (to be announced soon) and I'll certainly be attending one of Lucia's classes myself. She has a lot to teach me.
Lucia will be teaching two different classes about coffee processing.
April 21: Understanding Coffee Processing for Cuppers
If you’re a barista, roaster or coffee buyer come hang with me on Saturday April 21st from 12:30 to 2pm. The room is small, limiting it to 30 seats.
I'm excited to present a series of coffees that I've designed to demonstrate the power of processing on altering flavor. We'll cover advanced topics in coffee processing that go beyond reductionist terms like "washed" and "natural" and cup examples of custom-designed fermentations from Africa and Latin America against reference coffees processed using more conventional methods.
There are two sessions on April 19th and 20th specifically about processing techniques like Controlled Fermentation these classes are only for Growers and Producers who own or work in a Wet Mill. The session on April 19th will be in Spanish.
If you don’t have a Wet Mill where you can implement new protocols this is not for you - but if you buy from producers that will be in Seattle - please forward this link to them
Map It Forward Events in Seattle This April
Mar 06, 2018
My good friend, the irrepressible Lee Safar of Map It Forward, will be offering two classes this April in Seattle during the SCA Expo week. Lee has partnered with established, successful coffee pros to put on the Map It Forward series in an attempt to mentor coffee professionals in planning their coffee careers. The series is innovative and only gets better every session. All classes will be available both in real life to about 35-40 attendees, as well as broadcast virtually to a private Facebook group.
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MAP IT FORWARD - How To Map A Successful Career & Business As A Coffee Roaster
I'm pleased to announce I'll be co-hosting this event Lee on April 21st from 3:00--6:00. We designed this seminar to inform and empower current and future roasters (and business owners of roasting companies) in the specifics of mapping a considered career path as a roaster in today's coffee industry.
Please click here to learn more about the event and to purchase tickets
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MAP IT FORWARD: How To Map A Successful 10-Year Career As A Barista
Lee will co-host this event with our friend Jared Truby, aka 1/2 of Trubaca, aka co-founder of Cat & Cloud, aka the guy who made me a famously awesome cappuccino about 6 years ago :). Jared is one of my all-time favorite baristas, and anyone in the industry could learn a lot from his enthusiasm and attitude toward service.
Please click here for more about this event and to purchase tickets
#raotips
Mar 03, 2018
As some of you know, I've begun a daily Instagram feature "Coffee Tip of the Day." I'm attempting to offer bite-sized bits of coffee knowledge as often as possible. If you'd like to check it out, follow me @whereisscottrao. I aim to be the first IG user to have a decent following without resorting to memes or photos of "instagram models." I know, I'm too old-fashioned.
Comments are welcome and I'd love suggestions if there are any subjects you'd like me to address. But please, remember these are quick tips; the last time I asked for requests, people wrote 200-word questions about roasting. :0
See you there.
Second Melbourne Class Added!
Mar 02, 2018
I'm pleased to announce that tickets are selling like, well, like flat whites, for the Melbourne Roasting Masterclass, so I've decided to add a second class on March 23 from 8am--11am. This class will also be held at the Five Senses Training Centre. Please see here for tickets and details.
Please contact me directly if you have any questions or concerns: scott@scottrao.com
Please do not contact the fine folks at Five Senses with questions.
See you there!
MAP IT FORWARD: Mapping A Career and Business In Wholesale Roasted Coffee Sales (March 11)
Mar 02, 2018
Two of my favorite coffee people, Lee Safar and James Marcotte, will be co-hosting this event on March 11. You can attend virtually, or in person if you're in the Los Angeles area.
Lee founded Elixir Specialty Coffee and the Map It Forward series. She's at it again with an innovative seminar focused on mapping a career in wholesale roasted coffee sales.
James Marcotte is the guy who got me into coffee 25 years ago (!) and has extensive experience selling roasted coffee for Intelligentsia. James will have a lot to say about the job, the career path, and marketing beans. The event will be held in one of the most surprisingly bucolic neighborhoods in LA on March 11.
I'm happy to announce that I'll be in Melbourne during MICE to offer a roasting masterclass on March 21. I'm grateful to my friends at Five Senses Coffee for hosting the class, which will be held at their training center near the CBD.
Beyond the incredibly challenging masterclass material that you won't find anywhere else, I will be offering something special: effective, original methods to prevent ROR crashes. What I've learned is exciting, and this class will be the first time I share those methods with anyone other than a handful of clients.
PS If this class looks like it will sell out quickly, I will consider adding a class on March 23 at 8:00am. See you in Melbourne!
What is Baked Coffee? (MOST PROS DON'T KNOW!)
Feb 26, 2018
For years I’ve been promoting the idea of a steady decline in the ROR (rate of rise) during roasting. Recently I’ve heard of some "educators" publicly discrediting the idea of a steadily declining ROR, so I think it’s time to address this issue.
What is an ROR curve?
The ROR is the number of degrees per minute that the bean-pile temperature is increasing at any point during a roast. An ROR curve is a graphical plot of that data throughout a roast batch. The ROR tends to decline throughout a roast, primarily because the temperature gradient (differential) between the beans and the roasting environment decreases. Please note that the “real” ROR does not go up early in a roast as the curve shown here implies. The real ROR at the beginning of a roast is quite high and drops precipitously during the first minute; however, because the bean probe that recorded the curve was hot at the charge, and the probe took a few minutes to shed its heat and match the temperature of the beans, the curve incorrectly implies that the ROR began at a low negative number and increased for the first 2:30 of the roast.
What happens when the ROR “crashes”?
Somewhere around the beginning of first crack, the beans release a great deal of moisture from their cores in a short period of time. That moisture is cooler than the bean surfaces or the probe, and may cause the ROR curve to drop rapidly. This is known as an ROR “crash.”
What is “baked” coffee?
Despite what you may have heard about baked coffee being caused by long roast times (I used to believe that after hearing it for years, but ultimately did not find it true at the cupping table), negative RORs, or some strange combination of factors, the main cause of baked coffee is a pronounced ROR crash, or more precisely, a drastic change in the slope of the ROR. Relative to a well-executed roast, baked coffee seems hollower, flatter, and less sweet. Of course, there are degrees of ROR crashes and degrees of baking. A roast may be slightly baked or extremely baked, and the severity of the ROR crash will correlate with the degree of baked flavor. As brewed coffee or in a cupping, baked roasts will lose more of their tartness, sweetness, and warmth of flavor as they cool. Green buyers may make the mistake of blaming the green quality when a cup’s acidity and sweetness “fall apart” as it cools, when the real culprit is a baked roast. (That's not to say green quality doesn't affect the retention of sweetness and acidity as coffee cools; it's just not the usual cause.)
This roast is definitely baked. Note the change in the slope of the ROR from flat (or even rising a little) to nearly vertical.
This roast is definitely not baked. Note that the orange curve is the environmental-temperature curve.
The fine print
There are some nuances to consider when deciding whether an ROR curve indicates baked coffee.
The orange ROR curve came from a 10mm probe; the blue curve from a 3mm probe. The probes were installed 3cm from each other in the faceplate of a Probat G60.
The speed at which your bean probe reads temperatures will affect how “crashy” an ROR curve looks. For example, the Cropster graph above shows two ROR curves from the same roast batch; the blue ROR curve’s data came from a 3mm-diameter probe and looks slightly baked. The lower, round, orange ROR curve’s data came from a slow 10mm probe and doesn’t show the ROR crash. Please keep in mind that these two curves are data from the same roast batch, but the smoothing effect from the slower 10mm probe hides the ROR crash.
Below is a roast from a Probat with a slow, 6mm probe; note that the crash doesn’t look dramatic, but that same roast would look very baked had the probe been faster:
Note: the pale blue lines are the "reference" curves, or target curves, for the coffee shown.
I’ve come to believe that if a crash happens very late in a roast, for example in the last 30 seconds, the coffee will be less baked than if the crash had happened earlier. I see many “Nordic” style roasts with a high ROR at first crack followed by a brief crash just before the drop. Sometimes those batches taste a bit baked and sometimes they don’t.
This is fairly typical of many roasters' attempts at "Nordic style" roasting, wherein the ROR drops quickly in the last 30 seconds of a roast and may or may not show signs of baking.
How do I know this is true?
There are many “experts” who will mock the ideas in this post. And I'm sure many readers are thinking "my RORs crash but MY roasts aren't baked." All I can say is that if you ever master avoiding the crashes, you'll change your mind. Until then, rather than dismiss the ideas here, I hope you attempt to test them properly.
I’ve worked on this concept with several hundred clients over the past few years and not one of them has ever wanted to go back to crashing RORs once they had learned to avoid them. As well, almost all of them can now taste a roast blindly and know whether its ROR curve had crashed, which is strong validation of the idea. (If looking at curve can tell you whether a roast is baked, and tasting a roast can tell you about the general curve shape, that’s the definition of validation.) It's more difficult to detect baking in naturals or in coffees like Kenyas with massive amounts of ripe-fruit potential. I'm sure many readers have tasted Kenyan coffees that crashed hard yet tasted quite sweet and fruity. In my experience such coffees got even better when roasted without the crash.
Please try not to get confused, as many do, about the relationship of baking, underdevelopment, and roasty-ness. Crashed roasts are more likely to flick and more likely to be less developed, so many roasters are used to those issues coexisting in a single batch. That muddies the issue a bit, so please try to isolate and taste roasts that are definitely well developed and crash but don’t flick; train your palate on those roasts vs. roasts with smooth RORs and eventually you'll always know when a roast is baked.
I recommend that you trust your taste buds, not what I tell you (I mean you're welcome to, but...), and certainly not what the industry teaches in its certification courses — the "baked" samples in those courses are usually roasted with ridiculous methods that also cause roasty flavors, confusing students and not providing a clear demonstration of baked flavor. Instead I suggest you do the following if you want to learn to identify baked roasts:
If your bean-probe diameter is greater than 4mm, please replace it with a smaller probe before forming strong opinions about how “crashy” your RORs are. (If you have a "grounded" probe, >4mm may be fine, but that's an issue to discuss in a post some other time. For now, just check that your probe indicates the turn no later than 1:30.)
Ensure your probe is fast enough and your software settings are appropriate to provide useful ROR data.
Suggested settings would include sampling intervals of one second (standard in Cropster), an ROR interval ("delta span" in Artisan) of no more than 15 seconds, and no additional smoothing of curves when using software that offers various smoothing options. Those parameters, plus a fast probe, usually ensure quality data.
Cup blindly— always.
Find the correlation between ROR crashes and flatness vs. sweetness in the cup.
Always compare cupping results to ROR curves after you have tasted the cups and taken notes.
Thanks for reading. I'd love to hear some dissenting opinions and also your experiences with baked roasts and roast curves.
Decent Mice
Feb 25, 2018
Good news, Melbournians! John and Bugs of Decent Espresso will be in Melbourne to demo the DE1+ machine during MICE. I'll be helping them (aka acting like I understand what John is talking about while I pull shots and keep the coffees dialed in) for a demo off site as well as at MICE itself.
Our friends from the St. Ali family have been kind enough to share space in their booth with us. Please stop by the St. Ali booth, say hello, and check out the future of espresso. Take a selfie with Matt P while you're there; he loves it :).
We'll also be serving coffee from the DE1+ at the Five Senses Training Centre at 300 Rosslyn St, Melbourne on March 22 at 8am-10am. Hopefully I'll get my hands on a roasting machine to roast some tasty Kenya for the event.
Drip vs. Immersion: We May Be Calculating Extraction Incorrectly! And, A Contest.
Feb 19, 2018
Several readers recently requested a post explaining the differences in measuring extractions of drip vs. immersion brews. I have always wanted to write about this, but didn’t think anyone would want to read such a post :). I’m glad I’ve got a few geeky readers out there.
Writing this post got me to thinking, measuring, and questioning. What I found was shocking, so I discussed it with my friend Dan Eils, who's a brilliant scientist with a keen interest in coffee making. I think Dan and I are onto something, and it implies we all may be calculating extractions incorrectly. This post wouldn't have been possible without Dan's help and our enjoyable week-long debate over these issues.
This post will take some effort to fully grasp, but if you measure extractions, I think it's essential to read this and discuss it. Comments are welcome, and sharing this post with other coffee pros is also welcome, as I'd like to get feedback and ideas from many sources. My hope is that the ideas in this post reshape how we calculate extraction and also help users of the coffee refractometer understand the numbers a little better. I also hope that others will point out any errors in my thinking or calculations.
First, a little primer...
Concentration Gradient
When water mixes with coffee grounds, coffee solids dissolve in the water and move from the grounds to the surrounding slurry by diffusion. (This does not apply to espresso.) The rate of diffusion is determined primarily by the concentration gradient: the difference in solids concentration between the grounds and the slurry. The higher the gradient, the faster extraction will occur.
Immersion Brewing
During immersion brewing, upon water contacting the grounds, the concentration of coffee solids in the slurry increases rapidly, and then continues to increase at a progressively slower rate, asymptotically, for the rest of the brew. An example of this is how the color of coffee in a French press hardly looks much darker from a few seconds into the brew until a few minutes later. Another example is how in cupping, brew strength doesn’t change much in the time window of 9:00–-20:00 in which you likely slurp and spit.
Brew and serve a French press, and you’ll notice that the strength of the coffee left behind in the grounds (the “interstitial liquid”) is nearly identical to the strength of the coffee in the cup. If you were to squeeze the grounds at the bottom of a French press after decanting, the strength of the liquid that oozes out would be approximately the strength of the liquid in the coffee served, or perhaps slightly stronger.
Percolation brewing
Percolation refers to brews in which liquid extracts coffee solids by passing through the bed of grounds. Just to be clear, I’m not referring to those nasty old “percolators” you may remember your mom breaking out for large gatherings when you were a kid. And trust me, there are few more memorable aromas than baked-in, rancid robusta oils from a dirty percolator in 1977.
In a percolation method such as batch brew, during most of the brewing cycle, fresh, clean water is added to the slurry while solids-packed liquid leaves the slurry. That causes the slurry’s solids concentration to decrease throughout the brew. So, while the strength of the slurry of a French press is always getting stronger, the strength of a slurry during percolation is always getting weaker. This is important, and is the primary reason percolation is a more efficient extraction method than immersion.
Curves are for conceptual purposes only; they were not derived from real-world data
Why your software has separate modes for drip and immersion
This is a short version of what I was taught years ago:
At the completion of a percolation brew, the slurry’s TDS is extremely low. Therefore, when considering how much coffee solids extracted during a percolation brew, you can more or less ignore the dissolved solids remaining in the slurry liquid. That is why Extract Mojo software (aka Coffee Tools) uses the brewed-coffee weight as the multiplier for the TDS to determine total extraction-- almost all of the extracted solids are in the cup.
Standard percolation extraction measurement:
When measuring the extraction of an immersion brew, the liquid left in the slurry is full-strength coffee (or possibly a tad stronger). Even though those solids still seem to be in the grounds, a good deal are in the interstitial liquid, which is really liquid packed with extracted solids that just never made it into the cup. That is why the software uses the brew-water weight to calculate the extraction of an immersion brew: the slurry liquid is just like brewed coffee left behind in the filter.
Standard immersion extraction measurement:
Theory vs. Reality
Here's the surprising part: I decided to sample a few ml's of liquid from the spent grounds of a few v60s and batch brews, and they measured anywhere from 0.8%--1.3% TDS. For reference, the brews were all in the 1.3%--1.4% range. This shocked me: you know how the last bit of liquid flowing from the basket in a batch brew looks like very weak coffee? It is, but whether due to channeling or the slowness of diffusion or some other reason, it's apparent that the liquid left behind in the slurry is stronger than the last, weak bits of coffee that flow from the basket during a brew.
Let's say the slurry liquid of a percolation brew is 1.0% TDS. If the slurry liquid weighs approximately twice as much as the dry grounds, counting the extracted solids in that liquid would have a big impact your extraction calculations. I think our calculation method may need adjusting.
Two liquids in the slurry
If you use Coffee Tools software, you've seen the term LRR: liquid retained ratio. LRR varies with brewing method: the coarser grind of a batch brew holds a touch less liquid than the finer grounds of a v60, and a siphon has a very low LRR due to suction literally vacuuming the interstitial liquid from the coffee bed. For the sake of this discussion, let's keep it simple and assume a percolation LRR of 2g/g of dry grounds.
It's speculative, but Dan and I agree that the liquid trapped within the grounds at the end of a brew is probably pretty strong, or at least stronger than the interstitial liquid. If you begin with one gram of dry grounds, you may end up with approximately one gram of strong liquid trapped in the grounds and one gram of weaker interstitial liquid. The solids in the liquid trapped within the grounds are, by definition, not extracted, so they should not be a part of any extraction calculation. The relevance of the solids within the interstitial liquid is more debatable.
A Proposal
For the five of you who made it this far, thanks for hanging in there. And I'm sorry you don't have better things to do than to read my blog. :)
I propose that we consider changing the way we calculate extraction. I think we should try to count the interstitial slurry liquid, but not the liquid trapped within the grounds, in our calculations. The current equation to calculate immersion extraction counts the solids-packed liquid still trapped within the grounds, but it probably shouldn't. Likewise, the percolation calculation doesn't count the extracted solids in the interstitial liquid, but it probably should.
Modified extraction calculations
Percolation (we've added the weight of the interstitial liquid)
The two equations above are the same, the second is just the reduction of the first.
We have added the dry-ground weight to the multiplier here because that happens to be about the weight of the interstitial liquid. This modification is flawed in that the interstitial liquid's TDS is likely a little lower than that of the brewed coffee. I don't have enough data to say how much we should adjust that liquid's TDS; it's likely that its TDS will typically be about 75% of that of the brew's, and perhaps we should use .75 x the dry coffee weight instead, which would make the total adjustment + .75*TDS. The jury is out. (Please realize the extraction increased by a tidy 1 x TDSsimply because of our assumption about the amount of interstitial liquid.)
Immersion (we've subtracted the weight of the liquid trapped within the grounds)
The second equation above is a reduction of the first. We have subtracted the dry ground weight from the multiplier because that is also the approximate weight of the liquid trapped within the grounds.
Two examples
Percolation: Let's say you measure a v60 made from 20g grounds and 360g water, with a brewed-coffee weight of 320g and TDS of 1.4%.
By the old method, the extraction would be 22.4% (320 x 0.014 / 20 = .224 = 22.4%)
By the new formula, the extraction calculation would be 23.8% (just add the TDS to the extraction %)
Immersion: Let's say you brew a French Press with 20g grounds, 360g water, and TDS = 1.4%
By the old formula, the extraction would be 25.2%
By the new formula, the extraction would be 23.8%
The Fudge Factor
This method is not precise, given that we're estimating, and probably overstating, the TDS in the slurry liquid of percolation brews, and we're assuming a very tidy scenario of LRR=2 with exactly half of it in the grounds, half in the interstitial liquid. In other words, the fact that both methods showed 23.8% is mostly a fudge. The calculations would have to be adjusted for brewing methods like siphon or espresso, as they have a LRR of approximately 1, so I would use the old percolation formula for them. Dan and I have wrestled with this issue for a few days, and we agree that any extraction numbers are only relevant in context (grinder, brewing method, etc) and that there is no perfect method for doing this. Some cynics will say that calculating extraction is worthless because the numbers are a somewhat malleable, or because they need context. Those same people must prefer to roast without a bean probe or Cropster, as roasting data suffers from even more imprecision and need for context. There will always be doubters, and that's okay. Those of us who have been diligently measuring extractions for years have reaped tremendous benefits in our understanding of coffee making and our ability to communicate about brewing.
Conclusion
I'm sure the two people still reading are wondering things like "do we really need this complication" and "why doesn't Rao have a life?" Both are excellent questions and I don't know the answer to either. I like that this new method resolves the differences in the extraction calculations of drip and immersion brews. It's also possible, though I don't have any experience to confirm this, that your subjective ideal extraction numbers for a drip and immersion brew for a given coffee will get closer. That's not too important, but it would be a nice perk. (sorry)
Map it Forward: Beginner's Roasting Workshop (1/7)
Dec 18, 2017
My friend Lee Safar has spent the past year developing “Map It Forward,” a workshop to help coffee professionals plan their coffee careers. Lee wanted help to offer a similar workshop for those interested in mapping a career in roasting, so last week at the Copa Vida roastery in Pasadena (thanks Steve!) I spoke at the first Map It Forward: Roasting workshop with Lee and Sumi Ali. The workshop was a success, with dozens of people attending in person as well as virtually. We received heaps of positive feedback, and many attendees requested a beginner’s class on roasting.
We’ll be offering a beginner’s roasting class at 11am PST on January 7, 2018 at Common Room Roasters in Newport Beach, CA (thanks, Ed!). We have space for about ten students to attend in person, and many more to tune in online.
The workshop is what I would consider a beginner’s class, though given the current, abysmal state of roasting education, the industry would probably consider this an “all levels” class. I’ve yet to meet someone who had attended a beginner’s roasting class and walked away with any accurate, practical knowledge. I’m frustrated each time I hear about what was “taught” in standard, industry roasting classes. We’d like to fix this problem, and my goal is to help new roasters learn good habits and proper theory from day one.
The workshop will be three hours, and will consist of lecture, hands-on roasting demonstration, an extensive cupping, and all the Q&A you can handle. Both present and virtual students will be welcome to submit questions ahead of time as well, and we’ll do our best to answer them.
The cost will be $99. Details and tickets and are available here.
The 2:1 Ratio
Dec 18, 2017
If third wavers are good at anything, it’s following trends and adopting new dogmas. If I didn’t know any better, I would say that most young baristas are glued to Instagram all day, just waiting to see what trend they should unquestioningly follow next. Call me crazy.
One of the stickier trends in the past couple of years has been the near-religious adherence, at least in the US, to the 2:1 espresso-brewing ratio. I’d like to discuss what an espresso-brewing ratio (EBR) is, why it’s relevant, and why it’s a little silly for so many cafes to latch on to this suspiciously harmonious ratio.
What is an Espresso-Brewing Ratio?
Simply put, it’s the ratio of an espresso’s beverage weight to the weight of the dry grounds used to make the shot. For example, if a barista pulls a 36g shot from 18g of grounds , the ratio would be 2:1.
Why EBR is relevant
I suspect most baristas do not realize this: if you have exact targets for extraction % and TDS, there is only one EBR that can produce a shot that achieves both targets. For example, let’s say you desire a 20% extraction and 10% TDS. Using a slightly simplified calculation, the only EBR that can produce a 20% extraction/10% TDS shot is a 2:1 ratio.
For example, with a 20g dose and 40g shot:
10% TDS = 4g of coffee solids (10% x 40g shot = 4g) 4g of coffee solids extracted from a 20g dose = 20% extraction
A 2:1 EBR can yield a spectrum of extraction/TDS combinations; for example 8% TDS/16% extraction or 9%TDS/18%ext. But no other EBR can produce any of the combinations mentioned above.
What if you want 10% TDS and a 22% extraction? That requires an EBR of 2.2:1.* And so on. (Note that your EBR also happens to approximate the ratio of your chosen extraction% to TDS.)
*These calculations are slightly simplified to help illustrate the concept; please don’t get hung up on the imprecision.
Sam Sgambellone of Coffee Kaizen generously shared this chart showing the possible extraction%/TDS combinations possible with various EBRs. Thanks, Sam!
Why it’s a mistake for most cafes to get hung up on the 2:1 ratio
I’d like to offer three assertions:
1. A cafe should choose its EBR, ground dose, and shot weight as a system, based on the style and size of drinks it serves. 2. The “best” extraction % using a given set of brewing parameters (e.g. shot time, ratio, temperature, etc.) is usually the highest that one can achieve. Various combinations of grinder and espresso machine may call for different EBRs and extraction levels to yield the best-tasting shots. (i.e. better machinery can yield higher extractions at lower EBRs.) 3. Most cafes using a 2:1 ratio serve underextracted espresso and should explore higher EBRs to make their espresso riper, less sour, and less sharp.
Based on these assertions, the “one size fits all” approach to EBR seems a little unreasonable.
How to choose an appropriate dose and EBR
Let’s look at three espresso shots:
The first shot is destined to be drowned in a 16oz (450ml) latte in the US. For the coffee flavor to not disappear in the milk, the barista may want to cram as much coffee solids as reasonably possible in the drink. The barista may choose a large, 20g dose and a higher EBR, of let’s say 2.5:1. At a 21% extraction and 8.4% TDS, the baristas has added 4.2g of coffee solids to the latte.
The second shot is pulled by a barista in Rome, and is destined for a 5oz (150ml) cappuccino. The Italian barista will likely use 7g of coffee and a 2:1 ratio to yield a 19% extraction and 9.5% TDS. He will have added 1.3g of coffee solids to the drink. (It’s surprising but true: large lattes in the US and cappuccini in Italy are typically of similar strength. Italian capps likely often seem stronger due to frequent use of darker roasts and lots of robusta.)
The third shot is pulled by a barista in Melbourne as a “short black.” To provide high extraction and good flavor clarity using a light-roast geisha (washed, of course), the barista may choose a high ratio such as 3:1 and modest TDS. For example, most Australian baristas “split shots” (pull two separate shots per portafilter) and may use 20g of grounds and a 3:1 ratio to yield two short blacks, each a 30g shot from a 10g dose. Such a shot may have an extraction of 22% and TDS of 7.3% to optimize flavor and clarity at the expense of strength and body.
The best extraction is the highest extraction, within reason
I can’t tell you what the “best” extraction level is for your espresso shots. But I will tell you that you’ve probably never had an overextracted espresso. What?? Yes, it's true. Sure, you’ve had shots that were channeled, bitter, or had overextracted flavors. But when’s the last time you accidentally pulled, say, a 26% extraction, without doing something extreme, like using a 10:1 ratio? The “overextracted” shots you’ve pulled were channeled, or perhaps your burrs were dull or misaligned, but your shots were not overextracted in the mathematical sense. If you’re pulling 21% shots using an EK and you think they’re overextracted, check your burrs and your puck prep prior to lowering your extraction target.
NB: Your shots may not look channeled, but when you finally pull shots on a Decent Espresso Machine next year and get to see the volatility in the flow-rate graphs of your shots (the volatility indicates channeling), you’ll see that all shots channel. The DE1+ tells me that my shots channel, and so do those of several friends who have won the WBC. We’ve just never had the data and feedback needed to recognize and fix the problem. Maybe one day when we all have roller mills, Decent Espresso Machines, better puck prep, and perfectly-developed coffee, we’ll be able to routinely pull non-channeled, 30% extractions and decide our shots really are overextracted. Until then, you’re generally better off doing whatever increases your extractions. (As an aside, John Buckman of Decent is now possibly the world’s best barista at avoiding channels, as he has pulled more shots on the DE1+ than anyone else, and the machine’s feedback has made John’s learning curve nearly vertical. He also now knows more than anyone about shot dynamics and the effects of different puck-prep methods.)
Baristas should usually aim for the highest extraction possible when using standard EBRs (very high EBRs will always channel extensively, and in such cases maximizing extraction may not be wise.) If you taste symptoms of overextraction, work on your puck prep and ensure you’re using adequate preinfusion (very few baristas do).
Most cafes attempting to use a 2:1 ratio are underextracting their espresso.
The most important reason most baristas should question the 2:1 ratio is that they may be serving underextracted espresso. By “underextracted” I simply mean the coffee would taste better if the extractions were higher.
Simply put, if you’ve got a setup such as a Mazzer grinder (low extractions) and a La Marzocco Linea (no proper preinfusion, no pressure decline), and you use a 2:1 ratio, you’re likely underextracting. Using an espresso machine that offers slow, low-flow preinfusion, or a well-programmed pressure-profile machine, and/or using a higher-extracting grinder, such as a Mythos or a Peak, can each significantly boost extraction quality and quantity. Unfortunately, equipment selection is another area where baristas and shop owners do more trend following than analytical thinking, but more on that some other time.
How to test whether your coffee would taste better at a higher extraction
This is not a foolproof test, but it’s worth trying, and takes only a few minutes. Let’s say you typically pull shots with 2:1 EBRs using 18g in/36g out in 30 seconds. Try this instead: set your grinder one small notch coarser. Purge a couple of doses from the grinder. Pull a 3:1 ratio shot (18g in/ 54g out) in 30—35 seconds. You've now likely increased extraction by more than one percentage point. Assuming the shot did not channel more than usual, taste the coffee and evaluate whether you prefer the flavor to that of your 2:1 ratio shots. If you were underextracting at 2:1, you’ll likely find the 3:1 shot is juicier, less sharp, and less sour.
The test is imperfect, primarily because we’ve changed the flow rate, but almost all baristas who have done this test with me preferred the flavor of the 3:1 shot over the 2:1 shot.
The Upshot
When choosing an EBR, consider factors such as your preferred extraction level, TDS, shot weight, beverage size, the quality of your equipment, and the purpose of the shots (will it be served black? how much milk does it have to balance?). One factor to not consider is what everyone else is doing. Sure, if an expert such as James H. or Matt P. makes a recommendation, give it serious consideration and a fair trial. But if you make brewing and equipment choices based on what everyone else does, you’ll likely make average coffee (by definition, if you just follow the herd, your results will be average) and you may do something silly like spend ten years serving 1:1 ristrettos (remember those days?)
Thanks for reading. Please share your thoughts.
The Lucia Update (AKA The Yeast-Fart-Coffee Update)
Dec 18, 2017
Thanks to all of you who have expressed interest in tasting some of Lucia’s coffee. Our original intent was to offer coffee from her project in El Salvador, but the crop was late and we decided that ultimately it wasn’t the best choice to showcase her work. Lucia has instead chosen a coffee from Huehuetenango, Guatemala that should be available in January.
When the details are finalized, I’ll post them here and will also directly email those who have inquired about purchasing her coffee. The coffee will be roasted and shipped by the soon-to-be-famous Regalia Company in NYC.
More on this soon.
Looking Beyond Origin for Flavor Diversity
Oct 26, 2017
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Recently I’ve had the pleasure of meeting Lucia Solis, a fermentation expert who cut her chops in the wine industry. Lucia has been working in coffee for the past three years as a “coffee-fermentation designer”: she helps mills rationalize, improve, and customize their fermentation process.
The old (and current) view of fermentation is that it offers no opportunity for flavor enhancement, only risk. The new view (Lucia’s) is that it’s best not to leave fermentation up to chance, but rather to manage it in a way that helps enhance the final product while decreasing the risk of subpar batches.
Surprisingly, some green buyers have criticized Lucia's efforts, and seem scared that intentional fermentation design will either decrease the diversity of coffee flavors available, or somehow "ruin" coffee. Many new ideas are a little scary at first, but I'll support any new idea that promises to protect farmers from some risk, makes one small step in processing more predictable, and gives a processor a new tool in her toolbox.
Please read what Lucia has to say and decide for yourself. We’d love to hear from you.
Scott
P.S. I've arranged with an excellent roaster-friend in NYC to provide 250g bags of roasted coffee from Lucia's upcoming project in El Salvador. The beans will be roasted and available for sale around the first week of December. Please send me an email at scott@scottrao.com if you'd like to buy a bag. I do not have specifics yet about pricing or date, but I will get back to you as soon as I do. Supplies will be limited.
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By Lucia Solis
My work as a winemaker and now as a coffee-fermentation designer centers on one simple truth: fermentation creates chemical compounds with sensory characteristics. I was primed to focus on microbes due to my background in winemaking. I got my degree in Viticulture and Enology at UC Davis and worked for nearly a decade in wineries in Napa Valley, California before my background in microbiology and fermentation brought me to the coffee industry. Today, I travel to mills and coffee farms across Central and South America where I work directly with producers to change the way they process coffee.
One way that roasters show diversity of flavor is to offer coffees from different parts of the world. This practice emphasizes regional differences that highlight the effect of geography but minimize the role of post-harvest processing in flavor development. Most of the difference between coffees is usually attributed to cultivars, climate and growing conditions, but the contribution by microbes is frequently overlooked. The tiny microbes (yeast and bacteria) that transform the cherry fruit into parchment have the potential to impact flavor in a big way.
Turning the cherry into green coffee ready for roasting is a multistep process. Each step provides an opportunity to impact flavor and quality.
We have only a handful of words to describe processing methods, for example washed, wet, honey, or natural, but each of these words can encompass very different and complex steps. The steps and time involved in what someone would describe as “washed” process vary wildly based on the climate, altitude, cultivar, ripeness, tank design and myriad other variables impacting fermentation kinetics. A coffee could spend anywhere from 8 hours to 72 hours in contact with the mucilage (fermenting) before it is washed. The words “fully washed” might not even mean that a coffee was fermented – but even if you know with certainty that it had been fermented, a coffee dry-fermented for 8 hours will likely taste different from one fermented underwater for 40 hours; or one fermented at 700 meters altitude (MASL) at 80°F versus 1500 MASL and 55°F; or one fermented in wood versus ceramic tanks. And so on.
Not only do the words we use to describe the process lack specificity, there is little known about the flavor effects of different processes’ steps or the microbes involved during those steps. This is the focus of my work.
Before I could change the way coffee was physically processed by highlighting the effects of the microbes involved, I had to update producers' definition of “fermentation”. I had been trying to educate producers about the flavor effects of different strains of yeast and bacteria, but I was getting nowhere. I finally realized few people understood the value of fermentation in the first place.
I was using the word “fermentation” to describe a metabolic process whereby yeast and bacteria transform sugars into energy and flavor compounds. Yet the most common working definition for coffee purposes was “the step where the pulped coffee sits in a tank until the mucilage falls off”. This was like trying to teach roasters to roast with a declining rate of rise and realizing that they don’t understand the effect the thickness of the probe has on that curve.
In the wine industry, fermentation is extensively studied because it is a necessary step in winemaking: you can’t have wine without it. I noticed the coffee industry used the same word, but it had a very different meaning to almost everyone I talked to. I think the main reason for the discrepancy is that “fermentation” is optional in coffee; it’s just one method of isolating the seed from a cherry.
In addition to being optional, it is also not restricted to a single process as commonly thought. Fermentation is not only happening in tanks with wet process/washed coffees, it is an element in honey and dry/natural processed coffees as well. In every process where fermentation occurs there is the opportunity to impact flavor. Fermentation begins the moment that microbes, which exist on virtually every surface, find an entry point into the fruit. The opportunity for fermentation happens as soon as the fruit is picked or when there is damage to the skin (exposing juice) while the cherry is still on the tree.
To address the risk of a spontaneous fermentation in winemaking, some wineries pick at night (the coolest part of the day, to slow down microbial action), spray their grapes with sulphur dioxide to inhibit the wild yeast population coming in from the field, or store picked grapes in dry ice until they are ready to begin the fermentation with known and selected microbes.
Fermentation is a natural process that happens without human intervention. Winemakers actively chose whether they will risk a spontaneous fermentation or select their microbes and control the process. Even if they choose to use wild yeast and not commercial yeast, they are still making a decision that actively impacts flavor. Most commercial producers of fermented products (wine, bread, cheese, beer, chocolate) inoculate their fermentation. Inoculation is rare in the coffee industry because the focus has been on reducing the risks of processing, and the rewards have been poorly understood.
Wine, chocolate, cheese, beer and bread, a few examples of other industries that harness the power of microbes to achieve a desired outcome.
The coffee industry defines “processing” as the time between picking a cherry and sending it to dry, usually in the form of either a whole cherry (dry/natural process) or as parchment (wet process). The cherry skin serves as a protective boundary for the seed, and once removed it leaves the coffee seed vulnerable to spoilage. Most literature stresses the importance of expediting processing to reduce the likelihood of damaging or lowering the quality of the coffee. Extending the time between cherry and dried seed is seen as risky for quality. That is: the traditional paradigm suggests that fermentation offers no opportunity for flavor enhancement, only risk.
Traditionally the path from coffee cherry to dried green coffee was fraught with risk. The conventional wisdom has been to minimize fermentation time in order to reduce the vulnerability of the seed. An alternative method is to control and extend fermentation to yield positive flavor attributes while mitigating risk.
Though we can’t see microbes with the naked eye, we know they influence taste and aroma because we notice their impact when the fermentation goes wrong: we taste this in the form of cup defects. This explains the push for mechanical demucilagination by some experts such as Sivetz and Flavio Borem. At best, in this view, processing merely maintains the inherent quality of the fruit.
Flavor metabolites are basically yeast and bacteria farts. Which would you rather your coffee marinate in?
But what are the rewards? We know that processing can impact flavor in positive or interesting ways: this explains the ubiquity of honey-processed coffees and the presence of dry-processed coffees on offering sheets. That is to say, we know dry-processed coffees taste different from wet processed coffees, so clearly, processing impacts flavor – enough that some people reject all coffees processed by particular methods.
Producers can continue to rely on luck or choose to harness the power of the microbes that influence flavors in the cup. Let me alleviate the fear that if more producers select their microbes, coffee flavors would be homogenized. The cultivar, sugar and nutrient levels in the fruit, shape and material of the tank, ambient temperature, water quality, length of contact time and other factors will still impact fermentation. This means that we don’t eliminate diversity of flavors–but we decrease the occurrence of undesired flavors.
I reject the view that processing is simply about maintaining quality or reducing defects. I believe that certain practices like controlled fermentation can enhance and add value to coffee. Properly fermented coffee is a more complex and valuable product than coffee that has been mechanically demucilaged. Fermentation fundamentally transforms the raw materials by creating new flavors.
Like brew masters, instead of waiting a year with a barrel open to the environmental conditions and not knowing whether the results will taste delicious or like skunk water, producers can treat their coffee like a kettle sour and get the same flavors consistently. We use microbes to break down the nutrients in the mucilage and produce desirable metabolites. We brew a delicious “wort” and allow the coffee to sit in it past the point of a traditional ‘fermentation’, allowing the seed to absorb the wort and those flavors. Careful choice of microbes can protect the coffee from spoilage and pre-select the metabolic products we want – the ones that taste and smell good.
Controlling fermentation is key to harnessing the power of processing to create positive attributes. Fermentation, a biological process that occurs in every form of processing, is an opportunity to impact flavor, and all the steps from the farm to the patio can impact the quality and consistency of coffee. By understanding the power of fermentation and processing, producers and roasters can ensure diversity of flavors while improving the consistency and quality of coffee.
To see Lucia's coffee-processing photos, visit her on IG @lluciasolis
LA Roasting Cooperative
Oct 23, 2017
I know it's not a novel concept these days, but I'm opening a co-op roastery in Los Angeles. I had first attempted to partner with a friend to open a cooperative roastery in LA about six years ago, and that fell through, but I'm happy to announce that I've formed a new team ready to change roasting in LA forever. And it only took me 10 years :0. We've secured a great space near downtown LA to offer the highest quality cooperative roasting operation in the US.
Among the goodies we'll offer include:
Probat G45 roaster
Probat UG22 roaster
Mill City 15kg roaster
DE1PRO espresso machines
Various sample roasters analytical equipment (moisture, density, and aW meters, etc), and packaging machinery, etc.
All of our roasting machines will have the most advanced, proprietary software out there for any degree of roasting automation our users desire. I've used almost every roast-control system in the world, and I have to say: almost all of them are not worth using. We're going to offer best-in class controls and excellent, optional automation systems, as well as free consultations for anyone who joins and wants to up his or her roasting game.
We also have a few novel, exciting machines, features, and interesting neighbors up our sleeves. We'll publicly announce when we're ready to open our doors sometime in mid-2018.
Fines: October 23, 2017
Oct 23, 2017
Among the more interesting things that happened in my coffee life this week:
Seasoning my grinder with parboiled rice! Based on the online comments of Tom Chips in a 2013 home-barista.com post, I decided to try using parboiled rice (not raw rice) to season a new grinder I received last week. It worked like a charm. Tom is one of the most sensible people on that forum, so i felt confident in trying the parboiled rice trick. It saved a lot of time and money-- thanks Tom! (NB: Please don't ask me how much rice or where to get parboiled rice-- I don't consider my n=1 data to be worth sharing publicly.)
I signed a lease on a space in Los Angeles for a cooperative roastery (see recent post)!!
I tasted some stellar Rwandan coffee processed using fermentation methods custom-designed by my new friend Lucia Solis. The Rwanda was delicious, and easily the most interesting coffee I've tasted in months. Lucia has been applying to coffee what she learned during a career in wine fermentation, and the results are exciting. Look for a guest post by Lucia here in the next few weeks. I'm learning so much from Lucia and look forward to her sharing her ideas with my readers.
Stay tuned!
Immersion vs. Percolation: Have We Been Calculating Extraction Incorrectly?
Oct 23, 2017
Several readers recently requested a post explaining the differences in measuring extractions of immersion vs. percolation (drip) brews. I have always wanted to write about this, but didn’t think anyone would want to read such a post :). I’m glad I’ve got a few geeky readers out there.
Writing this post got me to thinking, measuring, and questioning. What I found was surprising, so I discussed it with my friend Dan Eils, my frequent partner in coffee debates. I think Dan and I are onto something, and it brings into question the way we have all been calculating extractions. This post wouldn't have been possible without Dan's help and our enjoyable weeks-long debate over these issues.
Comments are welcome, and sharing this post with other coffee enthusiasts is also welcome, as I'd like to get feedback and ideas from many sources to gauge whether it may be worth pursuing some new extraction equations.
First, a little primer...
Concentration Gradient
When water mixes with coffee grounds, extraction occurs by two mechanisms: first the water washes exposed solids off the ground surfaces, and then coffee solids dissolve in the water and move from the grounds to the surrounding slurry by diffusion (surface washing dominates espresso extraction, while drip and immersion methods favor inner-particle diffusion.) The rate of diffusion is determined primarily by the concentration gradient, the difference in solids concentration between the grounds and the slurry. The higher the gradient, the more quickly extraction will occur.
Curves are for conceptual purposes only. They were not derived from data.
Immersion Brewing
During immersion brewing, upon water contacting the grounds, the concentration of coffee solids in the slurry increases rapidly, and then continues to increase at a progressively slower rate, asymptotically, for the rest of the brew. An example of this is how the color of coffee in a French press hardly looks much darker from a few seconds into the brew until a few minutes later. Another example is how in cupping, brew strength doesn’t change much in the time window of 9:00–-20:00 in which you likely slurp and spit (the lower temperatures of a long immersion also contributes to the slowing extraction rate.)
Brew and serve a French press, and you’ll notice that the strength of the coffee left behind in the grounds, the “interstitial liquid," is nearly identical to the strength of the coffee in the cup. If you were to measure the drips from a French press after decanting the liquid that readily poured out, you'll find the strength of those drips would be approximately the strength of the liquid in the coffee served, or perhaps slightly stronger.
Percolation brewing
Percolation refers to brews in which liquid extracts coffee solids by passing through the bed of grounds. Just to be clear, I’m not referring to those nasty old “percolators” you may remember your mom breaking out for large gatherings when you were a kid. And trust me, there are few more memorable aromas than baked-in, rancid robusta oils from a dirty percolator in 1977.
In a percolation method such as batch brew, during most of the brewing cycle, fresh, clean water is added to the slurry while solids-packed liquid leaves the slurry. That causes the slurry’s solids concentration to decrease throughout the brew. So, while the strength of the slurry of a French press is always increasing, the strength of a slurry during percolation is always decreasing. This is important, and is the primary reason percolation is a more efficient extraction method than immersion.
The very slow addition of water to the slurry in percolation makes the initial TDS very concentrated. The late-extraction TDS of normal brews won't be as divergent as these curves imply, but if you were to brew each long enough, the curves would continue to diverge as shown. Curves are for conceptual purposes only.
Why your software has separate modes for drip and immersion
Standard percolation extraction measurement
This is a short version of what I was taught years ago: at the completion of a percolation brew, the slurrys TDS is extremely low, almost zero. Therefore, when considering how much coffee solids extracted during a percolation brew, you can more or less ignore the dissolved solids remaining in the slurry liquid. That is why the VST Coffee Tools app (née Extract Mojo) uses the brewed-coffee weight as the multiplier for the TDS to determine total extraction-- almost all of the extracted solids are assumed to be in the cup.
Standard immersion extraction measurement:
When measuring the extraction of an immersion brew, the liquid left in the slurry is full-strength coffee (or possibly a tad stronger). That is why the software uses the brew-water weight to calculate the extraction of an immersion brew: the slurry liquid is just like brewed coffee, left behind:
*Please note: this equation is slightly incorrect-- to be precise, you should increase the total water weight by the weight of the solids dissolved in the water. For example, if the total water poured is 100g and final TDS is 1.5%, then the total-water weight should really be 101.5g, not 100g. The difference in calculated extraction will be about 0.3% (eg. 20.3% vs. 20.0%).
Theory vs. Reality
Here's the surprising part: I decided to sample a few ml's of liquid from the spent grounds of several v60s and batch brews, and they measured anywhere from 0.8%--1.3% TDS. For reference, the brews were all in the 1.3%--1.4% range. This shocked me-- you know how the last bit of liquid flowing from the basket in a batch brew looks like very weak coffee? That had always fooled me into not questioning what I had been taught about the slurry liquid TDS being extremely low.
Two liquids in the slurry
If you use Coffee Tools software, you've seen the term LRR: liquid retained ratio. LRR varies with brewing method: the coarser grind of a batch brew holds a touch less liquid than the finer grounds of a v60, and a siphon has a very low LRR due to suction literally vacuuming the interstitial liquid from the coffee bed. For the sake of this discussion, let's keep it simple and assume a percolation LRR of 2g/g of dry grounds.
It's speculative, but Dan and I agree that the liquid trapped within the grounds at the end of a brew is probably pretty strong, or at least stronger than the interstitial liquid. The dissolved solids in the liquid trapped within the grounds are, by definition, not extracted, so they should not be a part of any extraction calculation. Therefore, we may be overstating the extractions of immersion brews. The relevance of the solids within the interstitial liquid is more debatable. In my view, the solids in the interstitial liquid have been extracted, they just never made it into the cup. Given the revelation that the TDS of the interstitial liquid is rather high, if you believe the solids dissolved in the interstitial to be "extracted", as I do, then its arguable that we've been understating the extraction levels of percolation brews. .
Computer art by Dan :). Note the ratio of inner-particle liquid to interstitial liquid is not to scale. Any resemblance to cartoon amoebas is purely coincidental.
A Proposal
For the five of you who made it this far, thanks for hanging in there. And I'm sorry you don't have better things to do than read my blog. :)
I propose that we consider changing the way we calculate extraction: perhaps we should count the solids in the interstitial liquid but not the solids still trapped within the grounds. The current equation to calculate immersion extraction counts the solids-packed liquid still trapped within the grounds, but it probably shouldn't. Conversely, the percolation calculation doesn't count the extracted solids in the interstitial liquid, but it probably should.
The original draft of this post proposed new extraction equations, adjusted to reflect the solids remaining in the interstitial liquid but not the solids dissolved in the liquid still trapped within the grounds. I’m hesitant to share them publicly without first gathering some feedback about this post. I imagine many coffee professionals won’t want to change the way they calculate extraction, and others may be excited by equations that would potentially harmonize the results of immersion and percolation brews. Currently, a "20%" percolation and a "20%" immersion brew don't taste as similar as most of us would like. If the new equations were to make the relationship of extraction numbers and coffee flavor more similar for the two types of brews, that would be a huge win. If the numbers don't harmonize the flavor/number relationship, then it's probably not worth going to the trouble of adjusting the system we use to calculate extractions.
I’d love to hear from you, even though there are no contest prizes on offer this time :).
Immersion, Percolation, and Grinding-- A Quiz and Contest
Sep 27, 2017
Let’s have a quiz and a contest. :)
Suppose you are to make these four brews using similar brewing ratios and a properly aligned EK grinder with settings 1–-11, with 1 being the finest setting, 11 the coarsest.)
Cupping, to be sampled at 12 minutes
v60, using 22g grounds and a 3:1 prewet plus one main pour
French Press, 4:00 brew time
Fetco, using 120g grounds, 2L of water, an appropriate basket size, 15% prewet, and 4:30 programmed brew time.
The Quiz:
Easy (easier?) question:
1. Put the brews in order, from finest grind to coarsest grind AND tell me why, other than empirical evidence, you chose that order.
Bonus question:
2. Based on a v60 grind of #6, predict the grind settings needed to make all four brews extract to roughly the same percent.
The reasoning behind the proper grind settings is straightforward, yet I have never been to a cafe that chose the correct order for those grind settings, let alone remotely correct grind-setting numbers for all of them ("correct" meaning settings likely to produce similar extraction %'s for all brews.) Makes you wonder about the dial-in process at cafes.
Since most readers seem timid about offering blog comments, I’d like to add an enticement: the first person to get #1 right with the correct reasoning gets a free signed copy of any of my books. If you already have my books, thank you, and I'll buy you a copy of The World Atlas of Coffee by James Hoffmann, because it's awesome. If you already have all of those books, I'll find a suitable replacement prize.
The first person to get both #1 and #2 correct earns a book or the option to receive the first production model of an exciting one-cup brewing gizmo I'm in the process of creating. (hint: choose this prize.)
Good luck!
UPDATE
Over 100 readers took a stab at the quiz. Thanks for writing, for having the guts to take a guess, and for the clear communication. I have high-quality readers!
I suppose I'm naive-- I've been asking friends for weeks how to motivate readers to comment on the blog. Now I know: offer them free stuff :)
THE WINNERS ARE.....
QUESTION #1 CAN GENCER!! Great job, Can. Your reasoning was close enough to what I was seeking. For someone who doesn't have an EK, your grind guesses were excellent, as well. I already knew from your prolific blog commenting :) that you have a keen mind.
QUESTION #2 CHRIS CAPELL!!! Judging this was tough. I wanted to be flexible about the numbers, so there was a little judgment involved. And a few readers offered good numbers but hadn't explained their reasons for answer #1.
Chris was the first to get in the ballpark with the numbers and explanation. Congrats Chris!! (full disclosure, Chris worked with me for about a year, circa 2008/9. At least now I know those endless chats about extraction paid off!)
ROSS NICKERSON, GABOR KISS, AND WESTIN MILLS all wrote in with an excellent all-around answers as well. Thank you.
Thanks to everyone for your answers. I'll post all of the comments now and will reply to a few.
QUIZ ANSWERS
FROM FINEST TO COARSEST:
French Press -> Cupping -> V60 -> Batch Brew *or* French Press -> v60 -> Cupping -> Batch Brew
This was not a trick- I was willing to accept either order, because measuring the TDS of a cupping is challenging. Whether you stir before sampling and from where in the cup you take the sample have a huge impact on the reading, and it's nearly impossible to trust the reading, as it's too technique-dependent. I measured a cupping this morning and found that depending on whether I agitated the cup, I could get readings of either 1.10 or 1.40. Go figure. Because of this, I wanted to be flexible about where readers put the cupping. Logically, cupping should be coarser than French Press because of the extended contact time in cupping.
THE REASON FOR THE ORDER
Several astute readers noted that percolation (drip) is more efficient than immersion at extraction. (*If a reader wrote "because drip extracts more than immersion" I didn't count that as specific enough--sorry)
Drip is more efficient than immersion primarily because during percolation, strong coffee is being removed from the slurry while fresh, clean water (good solvent) is being added, for most of the process. That keeps the concentration gradient in the slurry much higher for most of a drip brew vs. an immersion. Yes, there are other differences (temperature, amount of convecting of liquid, agitation, etc) but by far the main driver of percolation's superior extraction ability is the higher concentration gradient during much of the brewing process.
Assuming you've read every word of this blog over time (you have, right?), you may remember the discussion about the Ground Control brewer and how repeatedly draining and refreshing the slurry increases extraction a lot.
THE NUMBERS
These numbers are estimates, and I was simply looking for someone to come up with numbers in the ballpark. Depending on the way you sample from a cupping, the alignment of your burrs, etc, these can vary a bit. I was looking for something on the order of
FRENCH PRESS #4--#5 CUPPING #5.5--#7 V60: #6 (it was given) FETCO: #9.5--#11
V60 Video
Sep 16, 2017
I'm about five years late to the v60 party, but I've recently made an instructional pour-over video that I'd like to offer to readers. Plenty of third-wave cafes offer hand pours, and of the ones I've tried, I've enjoyed perhaps 10% of them. Uneven, low-temperature extractions are the norm.
Ten years ago, almost every barista who watched me stir a slurry was horrified. Five years ago, about half of third-wave baristas seemed to grudgingly accept that stirring may help extraction quality. Recently, the "Rao Spin" has made uniform extraction even easier to achieve, and the few whom I've demonstrated it for have been instant converts.
Most third-wave baristas seem to brew hand pours with no agitation, and their consistency is rather unfortunate. I still hear baristas say nonsense like "if my whole staff stirs hand pours, they will be less consistent." It's nonsense because if you don't stir, you're guaranteed a fair amount of inconsistency, because some grounds will remain dry through the entire prewet phase. Judicious stirring reduces channeling, makes extractions more uniform, and improves repeatability. It's not rocket science.
I pour v60's two ways: one pour or two pours. I find the one-pour method ideal for cafe service, because it's fast and allows the barista to spend much less time paying attention to the coffee. Total barista time spent standing in front of the brew should be 1:20.
The two-pour method requires a slightly coarser grind and adds 30--40 seconds to both the barista's task and the brewing time. I use the two-pour method when I have extra time and care about squeezing an extra 0.5% extraction out of a coffee.
I do not recommend brewing v60's with much less than 20--22 grams of grounds, as smaller doses require finer grinds (more fines = more bitterness) and average extraction temperature is lower in smaller brews. I'm also wary of breaking up the pour into more than two parts, as that makes the average extraction temperature much lower and may hinder extraction uniformity.
In the video, I demonstrate the one-pour method. With a great grinder (or sieved grounds), it's possible to extract 20% from a 22-gram v60 in less than 2:15 with this method. It's easy to adapt this method to other pourover brewers, including Chemex and Melitta. Just please be sure to use a ground dose suitable to the brewer.
If more cafes would use this method, long waits for astringent, muddled, or underextracted hand pours would be a thing of the past. But I'm not counting on that.
Please enjoy the video here, and don't be shy about commenting.
Fines: Fine for Espresso, Not So Fine For Filter
Sep 01, 2017
Every once in a while I hear or read a misunderstanding of the role of fines in coffee extraction and flavor. I’d like to discuss how coffee extracts, the role of fines in extraction, and how fines influence espresso and filter brewing differently. This is a long, technical post. But if you’re a coffee professional, it’s important you read, and probably re-read, it in its entirety. It is easy to make practical use of the ideas I present here.
If you find this post interesting or useful, please feel free to share, translate, or link to, this post.
Defining fines
A coffee bean is a complex three-dimensional matrix of cellulose strands coated with oils and other solids. These strands crisscross to form void spaces, or "cells." Researchers estimate a typical bean contains a million such cells. Roasting makes the cellulose brittle and grinding shatters the cellulose structure into various particle sizes. We call the smallest particles “fines.”
There is some disagreement about the definition of a fine. Most of the older research papers I’ve read referred to fines as cell-wall fragments containing no intact cells. Some people define fines as particles with diameters smaller than a certain size, say 50 microns. Others have recently defined fines as the particles in a certain section (the small hump, if you will) of a particle-size-distribution curve.
Typical particle-size distribution curve. Please ignore numbers, curve is for conceptual purposes only. Frequency here refers to weight or volume of particles.
My preferred definition of a fine is a cell-wall fragment containing no intact cells, because particles with intact cells extract differently than particles without any intact cells. Defined this way, brewing water can freely access all of the surface of the cellulose of a fine during extraction, but in particles with intact cells, some of the cellulose surface is inside the cells and not directly exposed to the water.
Choosing an arbitrary diameter-size cutoff to define fines makes little sense to me, as fines come in many different shapes, few of which are remotely spherical. Unfortunately, many scientific papers make the seemingly innocuous assumption that coffee grounds are spherical, for the sake of simplifying math and modeling extraction kinetics. That assumption is absurd and misleading, and the conclusions of such papers should be taken with a (spherical?) grain of salt.*
Looking at the little hump of a particle-size distribution curve (PSD) is an interesting way of grouping coffee grounds, but doesn’t provide an objective criteria or definition for fines, as that hump’s quantity, quality, and distribution change along with bean, roast, grinder, burr sharpness, burr alignment, etc, not to mention the method used to measure the PSD.
How coffee extraction occurs
There are two phases of coffee extraction: surface erosion and inner-particle diffusion. When water contacts a large ground-coffee particle, it rapidly dissolves coffee solids from the exposed surfaces of the particle. In perhaps a few seconds, such erosion is nearly complete.
Extraction from the intact cells within a ground occurs by diffusion, a process that takes minutes, and is never complete, at least under reasonable brewing circumstances. In diffusion, a concentration gradient causes solids to move from the particle to the water (solids will always move from an area of high concentration to a neighboring area of lower concentration.) The solids dissolved in the water then have to diffuse through the pores of the cellulose to reach the brewing liquid surrounding the particle. Inner-particle diffusion is slow because of its many steps: water must pass through the ground’s pores, dissolve solids, pass back out the pores, and ultimately carry the solids out of the coffee slurry into the brew. Extraction from larger particles is slower primarily because they have longer diffusion paths.
During a percolation process such as batch brewing, there will always be some dissolved solids left behind in the cells of the grounds, and some solids left behind in the interstitial liquid between grounds. In an immersion brew such as a French press, extraction is slower, primarily because solids-packed brewing liquid is not continually removed from the brewer, and during most of the extraction process, the concentration gradient is not as high as it is during percolation brewing. (This is why you should grind much finer for French press than for batch brewing, something that 99% of coffee professionals do not do.) As well, the liquid left behind in the coffee bed of an immersion brew contains much more dissolved solids than that of a percolation brew, making immersion brewing a less efficient extraction method than percolation. As a technical aside, the different solids concentrations remaining in the spent grounds of percolation and immersion brews is why Extract Mojo software has separate modes for calculating drip and immersion extractions. I'm happy to write more on that in another post if readers express interest.
One day we may be enjoying 30% extractions
(and I’m sure that really excites Matt.)
Approximately 35% of the mass of a coffee bean is water soluble. Without extreme temperatures, unrealistically long extraction times or additional solvents, it’s a fair to assume that you’ll never extract more than 35% of the weight of a pile of coffee grounds. Quality extractions of grounds from sub-$20,000 grinders usually top out around 23% in cafes but some massive roller-mill grinders produce grounds that readily extract a few percentage points higher. This is speculative, but it seems that one may be able to extract about 80%—90% of the soluble solids contained on a section of cellulose (i.e., a fine) before astringency and bitterness skyrocket. Say what? It may be possible to get a delicious 30% extraction? Perhaps, but not today, and not with your EK. You may be able to get to 26% or so with a decent grinder if you grind much finer than usual, arduously sift and remove as many of the fines and “boulders” (oversized particles) as possible, and batch brew the coffee. (Please don’t rush to judge the idea based on one such brew— the odds are low that you got the grind setting, sieving, and extraction all just right— it takes practice. But when you do get it right, the results are fantastic.)
Dear Vince, we may need new software when we get to 30% extractions, as my CoffeeTools tops out at 26% :).
My contention is that if a given section of coffee cellulose is 35% soluble solids by weight, it is potentially desirable to extract 30 of that 35. (i.e. 86% of the available soluble solids), and that somewhere between 30 and 35, extraction of astringency increases dramatically. In theory, if you had a pile of fines (fully-exposed cellulose fragments) and managed to get all of the particles to extract at exactly 30%, it would be an amazing cup of coffee; but that’s probably impossible to do.
The problem is that in everyday brewing, the solids from the surfaces of grounds (i.e. all of the solids on the fines and exposed surfaces of larger particles) will extract beyond 30% in seconds, while the 80%? of coffee solids extracting by diffusion will take minutes to reach merely 20%. Additionally, it’s likely that diffusion from some smaller particles or particles along channels in the coffee bed may eclipse 30% extraction before the coffee bed’s average extraction reaches 20%.
Why all of this science stuff matters
To make the best-possible filter coffee, it’s likely you should try to minimize fines (and boulders, for what it's worth). Given that fines are guaranteed to overextract and contribute bitterness and astringency, if you can remove fines or avoid creating them the first place, you’ll make a cleaner, sweeter cup with smoother mouthfeel. Most of us don’t enjoy astringent coffee, but if you do, that’s great, as tannins are excellent gut-bacteria modulators. I prefer to get my tannins from wine, thanks.
How to minimize fines, in order of importance:
Use sharper grinder burrs
Ensure grinder burrs are aligned as well as possible
Grind coarser
Use larger grinder burrs (burr design also matters, but larger is generally better)
Roast lighter
Avoid naturals at all costs*
Sift and remove the fines— this is difficult to do well, but worth experimenting with for home use and brewing competitions
Potentially, grind warmer coffee beans or use a warmer grinder (jury is out on this)
*Not true, but just felt like throwing that in there.
Along with minimizing fines, avoiding channeling in percolation brews is incredibly important for controlling astringency. Fines and channels affect cup quality in similar ways.
Fines are fine for espresso, to a degree
But what about espresso? Espresso extraction times are too short for extraction to occur via diffusion. Researchers have debated whether diffusion contributes at all to espresso extraction; if it does, its contribution is trivial. (I’m ignoring “espresso” made with minute-long preinfusion, "Slayer shots", and other such non-standard practices.)
The authors of Illy’s espresso book state that fines provide the necessary extraction surface, while larger particles are required to achieve adequate flow rate through the coffee bed of an espresso. If there are too few fines, extraction is low; if there are too few large particles, flow chokes. Given that espresso requires rapid extraction via erosion, some fines are likely to be required for a decent shot. (I think it’s theoretically possible to isolate grounds in the 100–200 micron range and use them to pull a tasty fines-free shot, but that’s not practical in a cafe.) What’s the ideal proportion of fines? Of course, no one knows. To complicate the matter, there seem to be two subsets of fines; let’s call them “larger fines” and “coffee dust.” The presence of the tiniest fines, or coffee dust, probably damages espresso quality by disproportionately slowing flow rates relative to their extraction contribution, thus requiring a coarser grind setting, which in turn decreases extraction.
Chris Hendon noted on my Instagram recently that grinding frozen beans produces less coffee dust and more of the larger fines, and they are of more uniform size. I have not seen the data, but that phenomenon may explain the success many baristas claim to have with grinding frozen beans for espresso. Minimizing coffee dust and producing larger, more uniform fines would almost certainly produce superior espresso extractions. Thanks, Chris, and I hope I have represented your findings accurately.
The bottom line
Congratulations if you’ve made it through this whole post. Now please read it again so it all makes sense :). Most importantly, I hope this post convinces you to be cognizant of fines production and the ways you can minimize it when grinding for non-espresso brewing. The two most impactful things most cafes can do to immediately improve quality are to replace old, worn grinder burrs with fresh, seasoned burrs, and to align the burrs as precisely as possible. Extractions will increase, flavor clarity will improve, astringency and bitterness will decrease, and mouthfeel will be smoother.
I’d love to know your thoughts. Don't be shy.
Interesting Flavor vs. Flavor Balance
Aug 13, 2017
I recently spent a week in Italy, where the difference between the third-wave palate, if you will, and the palates of the rest of the population, couldn’t be more pronounced. The average Italian coffee drinker prefers robusta to arabica (not a misprint), dark to light, espresso to everything else, and pretty much anything coffee-related that readers of this blog hate to anything they like. But they invented pizza as well as pistachio gelato, so I won't be too hard on them.
Why does the third-wave palate differ so much from that of the rest of the population? There are some obvious reasons (cultural bias), some some fairly obvious reasons (availability bias), and some speculative reasons (bacterial bias).
Say what? Yup, your gut bacteria determine to a large degree what you think tastes good, and it’s possible the polyphenols in coffee shape your gut population and the signals they send you, affecting your preferences. More on that soon.
The typical third waver seeks coffee that’s “interesting” while the average coffee drinker wants drinkability and flavor balance — nothing new there. Both may seek caffeine and pleasure in a cup of coffee, but the third waver probably focuses more on the intellectual pleasure of discovering and discussing flavors, while others seek the more visceral or physical pleasures coffee offers.
I was served an undrinkable, painfully sour Ethiopian espresso in Prague recently. The snooty, unfriendly barista seemed to think underextracted, channeled coffee with the pH of lemon juice was just right. I suppose the coffee was “interesting” but I didn't find any pleasure in it. It was exactly the kind of experience that would forever scare away a newcomer to third-wave coffee, unless that newcomer enjoys straight lemon juice.
There are third-wave companies that do a good job of bridging the gap between interesting flavors and flavor balance— Go Get Em Tiger comes to mind right away, as does St. Ali/Sensory Lab in Melbourne and Doubleshot in Prague, just to name a few. Too many baristas ignore flavor balance while searching for interesting, and i’d like to see more companies emulate those three. I know various people will define balance differently, but I'm referring to a cup that has identifiable sweetness, bitterness, ripeness, and caramels, with perhaps a winey acidity or sourness. A tiny proportion of third-wave coffee meets that criteria.
Kavarna Misto, Prague
But this post isn’t about my preferences vs. yours— that’s not important to me. What is important is that after 15 or so years of third-wave coffee, 99% of the world’s coffee is still dreck, and much of the other 1% is "interesting: but usually sour, baked, or vegetal. From that perspective, we haven't gotten very far, and I think one of the main reasons is our collective failure to serve balanced coffee, in part due to our myopic fixation on interesting flavors at the expense of balance.
I hear baristas talk about “educating” customers all the time. It’s my least-favorite phrase in coffee— not because I don’t believe in education, but because too many baristas uttering those words seem to mean it condescendingly. Memorably, a barista once said to me “I have to keep educating my customers that our coffee isn’t sour.” To which I replied “but your coffee is sour.” That shocked him, but upon reflection, and to his credit, he ultimately agreed and worked on it.
To be good educators, we have to be a good listeners. If a customer says a coffee is too sour, too bitter, or expresses an interest in more caramelly flavors or less acidity, it’s a good idea to meet them at least halfway in the discussion. If we just want to intimidate or scare off anyone who doesn’t already share our taste, we should keep doing exactly what we’re doing.
Winning over hipsters, well-to-do foodies, and trendy Brooklynites was relatively easy -- they were the low-hanging fruit of converts. If we want to be relevant beyond those demographics, I suggest that as a group we learn to respect and accommodate the non-third wavers’ preference for flavor balance, “educate” with humility and respect, and serve coffee that highlights the uniqueness of a bean while offering a balanced flavor experience.* Oh, and we should be nice when we do it.
*NB: Lest you think I’m advocating for dark roasts, I think one can easily create balanced, well-developed roasts dropped before first crack is complete.
Diary of a Coffee Consultant, Part 2: Florence to Lisbon
Jul 31, 2017
Moka Pot image "Evoluzione" reproduced with permission by CLET, a brilliant street artist based on Florence.
Stop 6: Florence
Prague and Florence are probably my two favorite European cities. Both city centers are famously overrun with tourists but somehow remain perfectly charming. As an American, I’m impressed with any tourist destination that hasn’t sold its soul and turned into an amusement park of a city, full of tacky and disposable junk.
If Prague has humility, good cafes, and tea, Florence has joie de vivre, gelato, and sex appeal. While the world associates Italy with coffee, there is only one company in Florence with very good specialty coffee: Ditta Artigianale. (There are also a few good local cafes in Florence that serve Ditta’s coffee.)
This may be a surprising statement, but… 99% of Italians do not value coffee quality. More precisely, they value coffee at exactly one euro per cup and they protest angrily when someone tries to charge more than that. To them, coffee is a commodity — 99% of Italian cafes charge exactly one euro for an espresso. The idea of “specialty coffee” doesn’t excite them, it offends them, and not because of the snobby hipster baristas. Can you imagine expecting all wine, cheese, or prosciutto to cost the same amount? Of course not, and Italians don’t, either. But somehow they don’t respect coffee quality as they do wine quality. (My anthropologist friend Kevin has an interesting hypothesis that Italians will value anything more highly if its raw materials are from Italy, but tend see non-Italian items as commodities.)
Ditta, owned by the famous and charismatic Francesco Sanapo, is quite unusual by Italian standards. When Francesco began offering special single-origin shots of espresso for 3-4 Euros several years ago, it was national news. Francesco was “ruining Italian culture” and seen as a criminal by some the public. That was despite Ditta still offering shots of a high-quality espresso blend everyday for a mere 1.50 Euros, also considered robbery.
Francesco won the Italian barista championship three times by preparing well and using high-quality medium-roast arabica coffee, while some other competitors were (seriously) using robusta. Since that time, most cities in Italy have gained one or two modern coffee bars. I suppose that’s progress, but there are literally a million espresso machines in Italy dispensing robusta, and Italian coffee bars probably go through as much sugar as espresso grounds, by volume.
I spent a day at Ditta working on their capable-but-complicated Brambati roaster. A 10kg Brambati is a complicated machine takes up as much space as a typical 30kg drum roaster. It is the roaster that would make Rube Goldberg most proud, and it has at least 10x the number of parts required to roast coffee with precision. I’ve been told the machine is so complicated due to Italian fire regulations and the like, but I think Italians secretly just prefer to make complicated machines.
That is, seriously, a 10kg roaster. Note the 7'-tall grey cabinet behind the roaster on the left- that houses the roaster's controls and is itself larger than a typical 10kg roaster.
Thankfully, Ditta has Michele Anedotti to manage the machine and navigate its countless screens of complicated software. I am proud of Michele: we’ve worked together twice in the past, and each year I’ve seen him, he has roasted better and better coffee. The roasts in our cupping session this visit were as good as any I’ve had in Europe.
At Ditta I got to roast and cup multiple batches of “anaerobically fermented” coffee for the first time. I also had the pleasure in Budapest and Florence of chatting with Felipe Croce of FAF about anaerobic fermentation. Felipe and his family are progressive, experimental coffee farmers, and Felipe gave me a crash course in Florence in the various types of fermentation they are exploring — perhaps more on that some other time. But let’s just say that while a natural is still a natural by any other name, things are getting interesting in the world of coffee fermentation. Talking to Felipe made me realize that my two interests, coffee and microbes, are merging more than ever (and yes, I remember I owe you a post about coffee and gut bacteria.)
Ditta’s roaster occupies a corner room in the massive roastery of Caffe Corsini, complete with three side-by-side 360kg automated roasters. Walking through roasteries like Corsini makes it seem silly that 1000s of specialty companies are roasting 1-2 kg at a time. Think about it: in a few hours, Corsini can roast the annual coffee needs of the typical third-wave cafe. Sometimes it’s shocking how big some roasters are, and how small our obsessive third-wave cottage industry is. Corsini is probably about the size of Intelligentsia, Stumptown, and Blue Bottle combined, yet you have almost certainly never heard of it.
Francesco of Lilliput.
Stop 7: A morning in Bologna
Whenever I arrive in Bologna, my first thoughts are “wow, this place looks old!” and “I should consider living here.” If Bologna only had a surf beach…
You won’t find much Bolognese sauce in Bologna, but you will find Europe's oldest university, countless beautiful medieval buildings, a fair number of shops that make farinata di ceci*, which is a treat for those of us who eat senza-glutine, and the home of the most passionate coffee people I know: Bar Aroma Degustazione E Vendita Di Caffe' Pregiati, aka Aroma. You could easily walk by Aroma and not notice it: it’s a modest little cafe on a quiet side street on the edge of Bologna’s center. By Italian standards, Aroma is maverick: it's a multi-roaster cafe serving numerous high-quality, light-roast, single-origin espressos and filter coffees, and they even have some nice teas and competition-style signature drinks. Run by the uber-friendly Cristina and her coffee-scholar husband Alessandro, two of the nicest people you’ll ever meet, visiting Aroma is like stepping into your friend’s kitchen, if your friend happens to make coffee with the precision and attention to detail of a watch maker. When you go there, you will feel like part of the family, and you will experience how third-wave service should be.
*Fun fact: Matt Perger loves farinata di ceci and his recipe is revolutionary.
This visit I learned that Alessandro had just written three coffee-training books in Italian for SCA. The books are lovely, with great graphics and Alessandro’s usual attention to detail. If you speak Italian and want to learn from a master, buy Alessandro’s books. I had only a few hours’ detour in Bologna, but I’m glad I stopped there to visit Alessandro and Cristina and to savor their coffee.
Stop 8: Prague 2
I had a few days with no work, so I returned to Prague. It’s one of my favorite cities and home to some of my favorite people as well as Salek, so why not? On this visit i got to be more of a tourist. I visited Gwilym, Petra, and Misa at their coffee training center in the pretty little town of Jilove u Prahy and they graciously took me to lunch at Florian, a charming, ancient pub. We went to Florian via a 30-minute walk through farmland on a 35c day, and only upon arriving they told me that we could have walked there in less than 10 minutes on a more direct path :). But Jenny Brown loved the walk through the farms and her joy, if not her rest stop on a pile of horse manure, made the sweaty walk worthwhile.
If you don’t know who Gwilym and Petra are, Petra is a former Czech cafe owner who has sold more copies of her Czech-language coffee book than I have sold of all of my English-language books combined. She’s a massive celebrity in Czech coffee, an expert trainer, and perennial World Barista Competition judge. Petra’s only shortcoming is she doesn’t like filter coffee much, though Gwilym tries to convert her on a daily basis, and I have faith he will succeed one day. Gwilym is a former World Barista Champion, co-owner of Prufrock Coffee, one of the world’s best and most sensible coffee trainers, and all-around nice guy. I recommend you find your way to Jilove one day and convince them to take you to Florian. There’s no better way to spend an afternoon.
Later that week we went on an adventure to Liberec, a small city an hour north of Prague. Lunch was at Mikyna, a delightful cafe that would fit in well in Melbourne, and after lunch we had coffee at Double Brew, a soon-to-open cafe run by some serious and friendly coffee guys. Before heading home we hiked up to Ještěd tower, a communist-era structure that looks like it’s from The Jetsons.
Ještěd Tower
Stop 9: Berlin
I confess that Berlin does little for me, but I’ve been sucked into visiting twice now by Kris Schackman, owner of Five Elephant. Kris is a great guy, and happened to have been a regular customer at my first cafe in the 1990s. We didn’t know each other then (Kris says he avoided me so I wouldn't notice how much time he spent at the cafe), but our lives have crossed paths many times since then. Five Elephant is dedicated to light roasts of very pretty coffees. We have had an interesting professional relationship over the years, as we’ve worked together but often disagreed in small ways about what makes an ideal roast. On this trip i was pleased to note that our preferences are now well aligned and their current head roaster Wojtek is humble, competent, and dedicated.
I happened to be in Berlin at the same time as the “Raw Hustle” tour, a series of talks by Matt Graylee and Matt Perger. I attended their talk at The Barn, and was fascinated by Matt Graylee’s creative model for helping coffee farmers improve the quality of their lives and coffees. To be fair to Matt P, I would have been fascinated by his talk as well, but his talk covered topics that he and I already discuss on a regular basis when we're not talking about ceci and gut bacteria. The very short version: automation and more accessible options (pods, capsules, fancy instant) will eventually devour specialty coffee.
Stop 10: Lisbon
I’ve always wanted to visit Lisbon, and this turned out to be a convenient time to stop there for a few days. Lisbon is an attractive city, with lots of beautiful old buildings, water views, and winding cobblestone streets. But fair warning: don’t visit without training on a Stair Master for a few months — Lisbon makes San Francisco look flat. Lisbon is also not the place for those like me who prefer to eat dinner before 9pm (most restaurants don’t even open until 7:30!), enjoy modern coffee, or eat gluten-free. I may have to scratch Lisbon off my list of potential future homes in case Trump is re-elected (sorry, didn’t mean to ruin your day with that thought.)
On my first full day in Lisbon, I met my gracious friend Gonçalo Duerte, Portugal’s biggest fan of good coffee and owner of Voo cold brew, at Wish Slow Coffee, where they serve Five Elephant. Someone had forgot the store key, so Wish Slow opened an hour late, a pattern during my stay in Portugal. Although Lisbon coffee shops typically open at 9am, even that seemed too early for many baristas to bother. The coffee was good, the service was surly (another pattern, unfortunately), and the food was pretty, but the portions were tiny, and shockingly expensive in an otherwise dirt-cheap city for eating. The saving grace of the cafe visit was Gonçalo’s unbridled enthusiasm for good coffee, and his clear-eyed awareness of Portugal’s medieval approach to coffee— almost all coffee in Portugal is made from dark, cheap, oily beans, usually involving robusta. If Gonçalo can infect 1% of Portugal with his level of enthusiasm, it will become the next Australia.
With Gonçalo in Ericeira
The coffee highlight of Lisbon was a tiny place called Hello Kristof that had a GS3 and a K30 as its only coffee equipment. I have friends with more and bigger equipment in their apartments. I’m not saying my friends are reasonable, just that Lisbon has a very long way to go before hipsters turn it into another Brooklyn. In my three days in Lisbon, the folks at Hello Kristof were just about the only coffee or restaurant staff I encountered who were friendly and hospitable.
I spent one night in the pretty beach town of Ericeira in the hopes of catching a morning surf before heading home, but alas, the surf report lied and I woke up to a flat ocean. After I made a lovely 7am batch brew of Five Elephant Kenya in my hotel’s kitchen, a couple of Israeli surfers asked to share some of my coffee (well, really they hovered til I had no choice). I gave them two mugs, which they returned, full, a few minutes later. Hilariously, they semi-apologized for not liking the coffee, implied that I had terrible taste (gee thanks, I’m glad I shared my coffee with you), and said they would go into town to get some “good coffee.” Note that almost all of the coffee in town was cheap, dark, and mostly robusta. :).
Thanks for reading.
Batch-Brew Basics, Continued...
Jul 21, 2017
One of the first posts on this blog was "Batch Brew Basics, Part 1". I've wanted to write Part 2 for a long time, but have been deterred by what I see in cafes: almost no one has the basics down. What's the point of an advanced post if almost no one has mastered the basics? Am I in the minority in thinking cafes should treat their batch-brew setup with respect?
I'd like to restate a few things that should be obvious to coffee professionals, but even well-known cafes seem to not get these points. To the 99.9% of readers who aren't coffee consultants, you'd be shocked at how many excuses cafe owners and baristas give me for why they can't be bothered to implement these simple practices that would greatly improve the quality of their batch brews.
1. Brew batches no larger than 2 liters. The only cafe I've been to in the last five years that was too busy to get by on 2-liter batches was in Grand Central Station. I can't even fathom how many cups of filter coffee they sell per day-- it's well over 1000. For almost everyone else, if you're serving fewer than 500 cups of filter coffee per day, two liters per batch is sufficient. If you're really busy, ie you serve more than 50 cups (12oz or 350ml) of batch brew per hour, it may be best to brew into a rotation of three tw0-liter carafes during those busy hours. That system will keep the coffee fresher and tasting better than will brewing fewer, but larger, batches.
There is no reasonable excuse for brewing 4-liter batches, or brewing into 4-liter urns, as I see so many cafes do. If you want your customers to respect batch-brew coffee, it will help to show it more respect from behind the counter first. Small batches, brewed into full carafes, turned over at least once per half hour is the way to go. Please.
2. Your bed depth should be 3cm--5cm... I applaud the many cafes, especially in Australia, trying to promote batch brew to a disinterested population, and brewing tiny batches (often 1--1.5 liters) to limit coffee waste. But if you want to brew one-liter batches, you either need a wire basket insert to narrow the diameter of your coffee bed (hence increasing its depth) or you need to find a machine designed properly to brew such small batches (and, honestly, the home-version of the Moccamaster is not a cafe-quality machine.)
3. This will shock many readers:
If your batch-brew grind setting is not in the 15% coarsest section of your grinder dial, there is a problem somewhere in your system.
That's not a misprint. You know that "auto drip" icon in the middle of the spectrum of grind settings on the old Bunn and Grindmaster machines? It's in the wrong spot*--- those settings were chosen years ago when 99% of those grinders were used in American restaurants where they skimped on grounds. Back then restauranteurs were using 30-40g/L (seriously-- in the 90s, when I tried to get my restaurant accounts to use 60g/L they thought I was mad) and grinding too fine in order to reach a palatable brew strength. A professional using a reasonable ratio ( i.e. 16:1--18:1) should grind very coarse. If you find the coffee is too weak in that coarse range of grind settings, at least one of these things is a problem:
The grinder burrs are too dull.
The bed depth is too shallow.
The brew time is too short.
The sprayhead may not be making use of the whole coffee bed.
There is no prewet phase at the beginning of brewing.
There are other potential problems, but these are the most common culprits.
*While we're at it, you may as well swap the "auto drip" and "French press' positions on the grinder.
4. Total Contact Time should be 6:00--6:30
This advice is more flexible than the other recommendations in this post, but 6:00--6:30 seems to be the sweet spot for batch brews. Try to get there without extending the programmed brew time past 4:30.
Thanks for reading.
Diary of a Coffee Consultant, Part 1: Bath to Budapest
Jul 18, 2017
I’ll get no sympathy for saying this, but sometimes work travel is exhausting. I know, I know, I get to work in places like Melbourne, Prague, and Florence regularly. And most years I incidentally get to avoid much of winter. This month has been one of those months that makes the endless hotel rooms, airports, and dishonest taxi drivers (I’d say thank God for Uber, but you can’t really say that anymore) all worth it.
Stop 1: Bath
Imagine a postcard photo of a perfect university town in the English countryside, complete with ancient thermal baths and a surprising number of good coffee shops, and you’re imagining Bath. I had the pleasure of spending two days in Bath and Bristol while working for the lovely people at Clifton Coffee Roasters, and finally got to visit Colonna & Smalls. I like a good coffee as much as anyone else, but what really wins my heart at coffee shops is a warm, inviting staff. Maxwell and his crew couldn’t have been more hospitable and friendly, and visiting them was a great start to my trip. I finally got to try Maxwell’s famous capsules, and other than first being served a natural from the capsule machine (he apparently doesn’t read this blog), the capsule coffee didn’t disappoint. Two days later, my final cup, an Aeropress Colombian, consumed while trading thoughts on water with Maxwell, was memorably delicious, and made it more difficult to leave Bath.
Not your father's Nespresso.
Stop 2: Bristol
My first regret of the trip was to not allow enough time to explore Bristol. Bristol is much larger and more vibrant than Bath, but also gorgeous and incredibly compelling, especially on a nice 24c day. I had been invited by Clifton Coffee Roasters to spend the day roasting together, followed by a brewing talk in the evening with their staff and customers, and finally a group dinner at Bosco, a bustling and modern Italian restaurant. Friendly, spirited discussions ensued about the merits of buying larger-than-needed roasting machines (my take: always do it if you can afford it), brewing smaller pots of batch brew (just do it; no excuses), and gut bacteria (of course). I’m grateful to Clifton for the work, the hospitality, and the enthusiasm; it was a blast.
Cupping at Clifton
On my way to London I stopped at Red Pig Coffee (redpigcoffee.com) for a short roast session with Adam Smith and a delightful lunch at Soho Farmhouse, not far from Oxford. The Soho Farmhouse www.sohofarmhouse.com restaurant is beautiful—it’s hard to describe, but it felt like a cross between a London boutique hotel and a country inn from Downton Abbey. It’s members-only, and very worth befriending a member :).
Stop 3: London
I confess: I like my cities warm and affordable. London is neither, unless you’re a Russian oligarch, and then it’s both. But this was my most enjoyable London visit to date, due to the 25c weather, two intense, intimate roasting classes at Prufrock, an intellectually stimulating dinner with James Hoffmann and John Buckman (it’s a joy to be the dumbest person at the table), and a chance to finally explore flow profiling on the DE1+.
Stimulating after-dinner conversation.
I hate to say it, but my day of cafe-hopping in London was a complete bust, full of charred-but-green-tasting light roasts sourced from far-away roasters (why bother buying such bad roasts from so far away?), oblivious customer service, and expensive batch brews served two hours after brewing (WTF?) Good coffees at Prufrock and newcomer Catalyst were highlights of an otherwise disappointing tour. I fear too many London cafes have become complacent, and like cafes in other very expensive cities, they are so focused on throughput that they forgot to offer a nice customer experience.
Prufrock hosted me for a double header of small roasting classes with a novel format: ten roasters came to each class and brought two roast samples each, along with printouts of the roast curves. We cupped all of the samples as a group, compared the cups to the roast curves, and discussed how the roasts could have been improved. The classes were very productive and genial, with all of the participants open to group feedback about their roasts, and I suspect most of them were fascinated to hear how various roasting machines required different strategies. Among the machines represented were the usual Diedrichs, Probats, and Giesens, as well as an electric roaster, a Loring, and a direct-flame Vittoria. Such classes are a lot more intense for me than the typical seminar, due to the frenetic pace of cupping, analysis, and questions I had to ask about each machine, but everyone seemed to walk away happy, and I’ve already received numerous emails from attendees who said their roasts were instantly improved by the experience. Thanks to Prufrock for its always-professional support of my classes, and to everyone who attended.
Stop 4: Prague
Dear Prague, You have far too many tourists, your language is inscrutable, drivers brake far too close to pedestrians in crosswalks, and you really need to serve vegetables other than potatoes in your restaurants. Beyond those small flaws, you are charming, gorgeous, romantic, and kind. And you are probably the world capital of hard-working, humble citizens.
Coffee people may not realize this, but not only is Prague littered with good cafes (thanks in part to the coffees of Doubleshot and the training efforts of Gwilym and Petra, coffee’s most-loved couple), but it also has as many good tea shops as good coffee shops. At the top of the heap is Tea Mountain. Tea Mountain specializes in Sencha, the Yirgacheffe of teas. After a coffee-cupping session, Jaroslav of Doubleshot and I stumbled into a cupping of new-crop Senchas at Tea Mountain.
Sencha cupping at Tea Mountain.
Martin, the owner and Japanese-tea obsessive, invited us to partake. It was a great experience, and I walked out with some lovely Kabusecha as well as my first-ever Japanese oolong, perhaps the finest beverage ever consumed on a Wizz Air flight (yes, that’s really the name of an airline.)
I came to Prague at the request of Jaroslav Tucek, one of the nicest people in coffee, and the co-owner of both Doubleshot roasters, and my favorite European cafe, Můj šálek kávy. If you go anywhere in Prague, go to Salek and walk two blocks to Tea Mountain afterward -- you’ll be thinking about buying real estate in the neighborhood as soon as you do. Salek is a special place: it manages to nail that rare combination of friendly service, great coffee, delicious food, and a warm atmosphere. Salek is the only cafe I’ve been to outside of Australia that serves both food and coffee on a certain level.
Můj šálek kávy
Doubleshot is, amazingly, owned by three men named Jaroslav — Czechs are nothing if not consistent in the way they name children. I spent two days roasting with the Jaroslavs on their restored UG22 and had some intense cupping sessions and discussions about roasting. Thankfully, in the end we unanimously agreed on our preferred roasts and we all left quite happy with the new profiles.
Stop 5: Budapest
This year’s World of Coffee was held in Budapest, a city remarkably like Prague, but somehow a little darker in character, at least in my experience. One of the brightest spots in Budapest is Espresso Embassy, run by the thoughtful Tibor Varady. Tibor was gracious enough to host my masterclasses a few years ago and I’ve been smitten with Espresso Embassy ever since. EE is set in a charming space with a ceiling made of brick arches, the staff is friendly and earnest about coffee, and especially during the week of the World of Coffee, the buzz at EE was electric. It was the social hub of the expo and I lost count of the number of spontaneous coffee-people reunions that took place there. I personally met at least 10 people at EE with whom I’d spoken to many times online but had never met in person. It was a treat.
Espresso Embassy hosted John and me for a demo of the Decent Espresso machine. It was the most fun demo to date, partly because the DE1+ now does flow profiling, which is fantastic, but also because the room was buzzing. So many people came that we needed to have two consecutive demos, with people waiting outside between the sessions. The crowd was extremely excited about the Decent, the Kenya was tasting big and juicy as espresso with none of the sharpness one usually expects, and after many demos using random espresso grinders, I was finally able to pull shots of a coffee I roasted using a Mythos. Kenya + flow profiling + Mythos = Scott happily had too much espresso to sleep that night.
We allowed random guys off the street to pull shots.
And the winner is...
I gave two roasting masterclasses in Budapest during WOC week. The classes were a resounding success, after four years my PowerPoint finally looks professional, thanks for my friend Tiffany’s design brilliance (if you want smart design work done efficiently and affordably, contact Tiffany.)
I enjoyed having such luminaries as Matt and Gwilym in the room. If I wanted to know if I was communicating well, boring everyone, or saying something too complicated, all I had to do was glance at Matt’s facial expression. Luckily, he seemed happy throughout class, but that may have been because he was sitting closest to the pot of Kenya and sneaking tastes every 10 minutes.
Thanks for reading and coming along on my journey. Tune in next week for Part 2: Florence to Lisbon.
Fines
Jul 18, 2017
This is the first post of a new feature of short posts, thoughts, and notices, tentatively named "fines."
Feedback is welcome, as always.
Espresso-Machine Service
I have a question for readers: If you have an annual service contract for espresso machine repair and/or service, what does it cost, and what specific services do you receive in return? John and I are discussing how to structure Decent’s service and repair arrangement for the PRO machines post-warranty, and any feedback would be greatly appreciated. Please send us a comment.
I think many readers would benefit from knowing what others are paying for service and maintenance. Thanks
Hottop For Sale-- THIS MACHINE HAS BEEN SOLD. THANK YOU.
Orange Cactus Rao
Jul 17, 2017
As you may know, I gave up on ‘YES or No by RAO” a while back. The game didn’t generate that many questions, and the questions I received were rarely the type that could be answered with a simple Yes or No. I spent much more time asking people to rephrase questions than answering them. I may never understand why that was, but it was time to cut the cord.
After cancelling YES or NO, I solicited suggestions from readers for an easy Q&A format. The most appealing suggestion came from Jake and Mike of the Orange Cactus Coffee podcast. They offered to collect and filter questions from their listeners, and submit them to me, and I would voice-record my answers, which they would then spiff up and turn into a short podcast. I’ve kept the answers dense and compact in order to give listeners the best value for their time that I can. Our podcast Q&A's will be no longer than 5 minutes each.
The first episode dealt with sweetness and acidity in coffee, and the second episode was about green-coffee storage concerns.
I’d love your comments and suggestions.
The Brewtime App
Jun 26, 2017
A few months ago I was contacted by a Czech team that had published a coffee-brewing app called Brewtime. They wanted some advice on coffee recipes. I liked the app for its simplicity and user-friendliness, so I asked them to allow me to overhaul their recommendations and help them long-term with their app. They have big plans for the app to be more than a simple set of brewing instructions, and I think they'll do nice things with it. Brewtime has just released the updated version. It’s free, and I recommend you download it and give it a shot. We’re going to be adding features and will create an ecosystem around the app over time, so keep it on your phone and stay tuned :)
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