The Science of Coffee

Latest Episodes:

Organic Coffee, Part 2: Why don’t we see more organic coffee farms? Mar 13, 2024

Show notes

Farming coffee organically is amazing because soils are more alive, birds and insects are more plentiful, farmers avoid getting sick with agrochemicals.
But, if it’s so great, why is less than 10% of the world’s coffee grown organically?
The fact is, going organic is hard. Much harder than growing coffee conventionally.
In this episode I show you the story of one of Central America’s most successful organic coffee cooperatives, RAOS, and the four big hurdles that stood in the way of their early founders who all dreamed of converting their farms to organic.
This story changed my understanding of farming and is now the reason I choose organic specialty coffee whenever I can.
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Dive deeper into organic coffee
Learn more about Sustainable Harvest’s Most Valuable Producer programme, their cupping app Tastify, and explore their range of certified organic and Fairtrade coffees
Explore RAOS (Cooperativa Regional Mixta de Agricultores Organicos de la Sierra)'s story for yourself
Are you a coffee farmer? Get in touch with Lalo Perez Varaona
Connect with my very knowledgeable guests
Lalo Perez Varaona - LinkedIn
Jorge Cuevas - LinkedIn
Andrea Futterer - GEPA website
Osman Contreras - LinkedIn
Roberto Rene Gonzales - Farm website
The Science of Coffee is made possible by these leading coffee organisations
BWT Water and More
Marco Beverage Systems
ROEST
Sustainable Harvest
Mahlkönig

The Science of Coffee is a spin-off series from James Harper's documentary podcast Filter Stories
Subscribe to A History of Coffee podcast

Use ProfilePrint to find the coffee your customers loved last year (without a week of cupping!). Use promo code "FILTER" to get 10% off your first year of a Mini Beluga subscription. Click here to discover ProfilePrint's many uses.

What kind of racing car does the Gaggia Classic GT home espresso machine remind you of? Use discount code FS202610 to get 10% off.

Organic Coffee, Part 1: The magic of soil Feb 26, 2024

Show notes

The world’s farming soils are deteriorating quickly.
Conventional coffee farming where plants are grown using agrochemicals allowed farmers to reap huge harvests these last 70 years. But these agrochemicals have been at the expense of soil health.
I travel to Honduras to explore a potential solution: organic coffee farming.
Come with me as I show you the organic farming tricks of Don Rufino, one of the region’s leading organic farmers.
He nurtures the soil around his coffee trees using mountain microorganisms, a huge diversity of shade trees, attentive tree pruning, and very funky batches of homemade bug spray.
The results speak for themselves: when I pick up a handful of his soil, it is moist, dense and writhing with life.
Could these cultivation techniques be the answer to the coffee world’s declining soil health?
Please spread the word about The Science of Coffee!
Discover how I make these Filter Stories episodes by subscribing to my Substack newsletter!

Follow me on Instagram and tag me in an Instagram story
Write a review on Apple Podcasts
Leave a 5 star rating on Spotify
Dive deeper into organic coffee
Explore Sustainable Harvest’s range of certified organic and Fairtrade coffees
Are you a coffee farmer? Get in touch with Lalo Perez Varaona
Check out Don Rufino’s organic cooperative, RAOS
Connect with my very knowledgeable guests
Lalo Perez Varaona - LinkedIn
Tommie Hooft van Huysduynen - LinkedIn
Alison Streaker - LinkedIn
The Science of Coffee is made possible by these leading coffee organisations
BWT Water and More
Marco Beverage Systems
ROEST
Sustainable Harvest
Mahlkönig
The Science of Coffee is a spin-off series from James Harper's documentary podcast Filter Stories
Subscribe to A History of Coffee podcast

What kind of racing car does the Gaggia Classic GT home espresso machine remind you of? Use discount code FS202610 to get 10% off.

Coffee Roasting, Part 2: Roasting made easy Feb 12, 2024

Show notes

Roasting coffee can be maddening. Just 4° Celsius is enough to make the same green beans taste distinctly different! And there are so many things roasters can play around with: temperature, time, fan speed, drum speed, types of probes…the list goes on and on.
So, if you want to start roasting yourself, where do you start!?
In the first half of this episode, I interview one of the world's leading roasting teachers who takes me through his published scientific research to give a clear answer. It’s as simple as 80%, 15% and 5%.
And then, in the second half, I show you why roasting coffee consistently batch-after-batch is so difficult. But these problems are finally being solved with smart technologies.
I visited the ROEST engineering team in Oslo and cracked open their innovative prototype P3000 roaster to show you the technology that allows anybody to roast coffee consistently and fully automatically.
I am so impressed with these innovations, I believe they’re going to change the coffee industry.
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Dive deeper into the science of roasting
Explore ROEST’s innovative products for the coffee industry.
Learn more from Morten Münchow and his coffee roasting courses
Read Morten’s paper in collaboration with the University of Copenhagen on Roasting Conditions and Coffee Flavour
Connect with my very knowledgeable guests
Sverre Simonsen - LinkedIn
Callum Gilmour - LinkedIn
Veronica Balduc - LinkedIn
Morten Münchow - Coffee Mind website
Scott Rao - Instagram
The Science of Coffee is made possible by these leading coffee organisations
BWT Water and More
Marco Beverage Systems
ROEST
Sustainable Harvest
Mahlkönig
The Science of Coffee is a spin-off series from James Harper's documentary podcast Filter Stories
Subscribe to A History of Coffee podcast

What kind of racing car does the Gaggia Classic GT home espresso machine remind you of? Use discount code FS202610 to get 10% off.

Coffee Roasting, Part 1: How heat transforms coffee beans Jan 29, 2024

Show notes

What flavours do you want from your coffee?
Every coffee bean begins its life green. And if you brewed it up without first roasting it, you’d get a yellow-green cup of grass-flavoured water.
But, as soon you apply heat to a bean, the flavour can morph to from something quite vegetative to a very acidic unripe fruit, then a very sweet fruit, and eventually dark roasted flavours.
This is the magic of coffee roasting!
In this episode of The Science of Coffee, I show you a full roast in action on the ROEST P3000, taste how coffee flavours evolve from acidic to bitter, and speak to leading coffee roasting scientists to reveal the mind-bending chemical and physical transformations taking place.
See for yourself Roest's innovative P3000 fully automatic roaster.
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Connect with my very knowledgeable guests
Mark Al-Shemmeri - LinkedIn
Callum Gilmour - LinkedIn
Veronica Balduc - LinkedIn
Anja Rahn - LinkedInIldi Revi - LinkedIn
Samo Smrke - Instagram
Morten Münchow - Coffee Mind website
The Science of Coffee is made possible by these leading coffee organisations

BWT Water and More
Marco Beverage Systems
ROEST
Sustainable Harvest
Mahlkönig
The Science of Coffee is a spin-off series from James Harper's documentary podcast Filter Stories
Subscribe to A History of Coffee podcast

What kind of racing car does the Gaggia Classic GT home espresso machine remind you of? Use discount code FS202610 to get 10% off.

Smell and Taste, Part 2: Are you and I tasting the same flavours? Jan 15, 2024

Show notes

Ever wonder why you and your friends can taste the same coffee, but you can’t agree on the flavour notes?
Join me as I explore this metaphysical mystery! I speak with leading scientists and ask: are the flavour receptors in your nose and mouth the same as mine? How does music and the shape of a cup affect what we taste? What about our different cultural backgrounds and language?
Best of all, I put all these questions to the test in the Athen’s World of Coffee trade show. Many poor unsuspecting Filter Stories spit, splutter and gasp in the name of science!
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See Marco Beverage Systems' SP9 for yourself, and discover their range of consistent and energy-efficient coffee brewers for your cafe.
Please spread the word about The Science of Coffee!
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Connect with my very knowledgeable guests
Helene Hopfer - LinkedIn
Joel Mainland - LinkedIn
Fabiana Carvalho - Instagram
Janice Wang - LinkedIn
Felipe Reinoso - LinkedIn
Freda Yuan - Instagram
Mandy Naglich - Instagram
The Science of Coffee is made possible by these leading coffee organisations:
BWT Water and More
Marco Beverage Systems
ROEST
Sustainable Harvest
Mahlkönig
The Science of Coffee is a spin-off series from James Harper's documentary podcast Filter Stories
Subscribe to A History of Coffee podcast

What kind of racing car does the Gaggia Classic GT home espresso machine remind you of? Use discount code FS202610 to get 10% off.

Smell and Taste, Part 1: How to be a better coffee taster Jan 08, 2024

Show notes

So you’ve just taken a sip of a very rare coffee, and flavours of passion fruit explode in your mouth.
But here’s the thing: that flavour of passion fruit is not coming from your mouth. It’s not even coming from your nostrils. It’s being picked up behind your eyes!
In this first episode of The Science of Coffee's second series, I unravel how our sense of smell and taste works to help you be a better coffee taster.
I shrink us down microscopically and we dive into your tongue to show you why good black coffee tastes sweet, even though there’s no sugar in it.
We then travel up into our noses and get stuck in a lot of mucus. This slime might be disgusting, but we need it to be able to smell well.
And finally, with the help of tasting expert and author Mandy Naglich, I show you three effective ways you can train yourself to be a much better coffee taster without having to go on any expensive courses. The trick is to train our internal flavour prediction models!
This episode will help you deepen your appreciation of coffee and its delicious complexity.
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See Marco Beverage Systems' SP9 for yourself, and discover their range of consistent and energy-efficient coffee brewers for your cafe.
Please spread the word about The Science of Coffee!
Follow me on Instagram and tag me in an Instagram story
Write a review on Apple Podcasts
Leave a 5 star rating on Spotify
Become a better coffee taster!
Pick up a copy of Mandy Naglich’s book “How To Taste”
Sign up for the Specialty Coffee Association’s Sensory Skills courses
Do an online sensory course with CoffeeMind
Connect with my very knowledgeable guests
Mandy Naglich - Instagram
Linda Bartoshuk - Website
Joel Mainland - LinkedIn
Fabiana Carvalho - Instagram
Janice Wang - LinkedIn
Peter Giuliano - LinkedIn
Bram De Hoog - Instagram
The Science of Coffee is made possible by these leading coffee organisations:
BWT Water and More
Marco Beverage Systems
ROEST
Sustainable Harvest
Mahlkönig

The Science of Coffee is a spin-off series from James Harper's documentary podcast Filter Stories
Subscribe to A History of Coffee podcast

What kind of racing car does the Gaggia Classic GT home espresso machine remind you of? Use discount code FS202610 to get 10% off.

Introducing: Season 2 of The Science of Coffee Jan 02, 2024

Show notes

We’re back with another series of The Science of Coffee!
Across 10 science stories, narrative audio producer and coffee professional James Harper takes you on a journey into coffee's hidden microscopic secrets.
James has spent the last year traveling to Central America, Greece, Norway, Switzerland and interviewing dozens of the world’s leading coffee scientists. This insights will help you appreciate coffee more deeply and make even better coffee at home.
We'll explore organic coffee growing, delve into the science of roasting, uncover optimal storage and grinding techniques, enhance your tasting skills through sensory science, and share James' journey towards thinking more like a scientist.
Press the Subscribe button so you don't miss future episodes! https://link.filterstories.org/3TdDnHO
Follow James on Instagram: https://link.filterstories.org/2Mlkk0O
The Science of Coffee is a spin-off series from James Harper's documentary podcast Filter Stories: https://link.filterstories.org/3ajoT5e
The Science of Coffee is made possible by these leading coffee organisations:
BWT Water and More
Mahlkönig
Marco Beverage Systems
Sustainable Harvest
ROEST

What kind of racing car does the Gaggia Classic GT home espresso machine remind you of? Use discount code FS202610 to get 10% off.

6) Sonic Seasoning Jan 03, 2023

Show notes

Imagine you’ve got a cup of coffee in front of you. You haven’t tasted it yet. You therefore don’t know what it tastes like, right?
Wrong. Some scientists argue that you actually do know what it will taste like (more or less), and the act of tasting simply confirms what you have already imagined it will taste like. And that’s because a growing body of research is revealing that sight, sound and touch all affect your expectation of a coffee’s flavours.
In this episode, I explore how certain sounds might make your coffee taste sweeter, while other sounds translate to bitterness. And I expose how some cafe owners might be ruining the flavours of the high-end specialty coffee you paid for without even realising it.
In the second half, I show you why so many of our scientific questions about coffee are going unanswered. I take you deep into the future of coffee science by explaining who’s doing research into coffee science, why they’re doing it, how much it costs and how you can get involved.
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Explore the technology behind Fiorenzato’s AllGround home coffee grinder
Want to listen to more documentary podcasts about coffee? Check out my Filter Stories podcast
Get more involved in coffee science!
Buy Brita Folmer’s The Craft & Science of Coffee
Read the Specialty Coffee Association's 25 Magazine for cutting edge insights into coffee science, business and sustainability, including Charles Spence’s article on sonic seasoning
Partner with the Coffee Science Foundation
Explore Felipe Reinoso Carvalho’s sonic research, including Diego Campos’ winning World Barista Championship routine
Apply to study at the UC Davis Coffee Centre
Do an online course with ZHAW’s Coffee Excellence Centre
Subscribe to Barista Hustle and complete their online coffee courses
Become a member of the Barista Guild, Coffee Roaster’s Guild, Coffee Technicians Guild and attend their events!
Connect with my very knowledgeable guests
Charles Spence - Academic profile
Fabiana Carvalho - Instagram
Janice Wang - LinkedIn
Felipe Reinoso Carvalho - LinkedIn
Chahan Yeretzian - LinkedIn
Bill Ristenpart - Academic profile
Peter Giuliano - LinkedIn
Jenn Rugolo - LinkedIn
Giulia Bagato - LinkedIn
Denis Girardi - LinkedIn
The Science of Coffee is made possible by these leading coffee organisations
BWT Water and More
Marco Beverage Systems
Trabocca
Eversys
Oatly
Fiorenzato
Subscribe to A History of Coffee podcast

What kind of racing car does the Gaggia Classic GT home espresso machine remind you of? Use discount code FS202610 to get 10% off.

5) Latte Foam Jan 03, 2023

Show notes

When was the last time you picked up a cappuccino with a mountain of foam perched on top? Maybe these are the cappuccinos you make every morning at home.
I personally really, really dislike them! The foam is cold, raspy, and gets in the way of the actual coffee liquid.
How much better would your mornings be if, instead, your cappuccino had that creamy, silky “microfoam” you find in a specialty coffee cafe?
In this episode, I take you deep into the bubbles of latte foam to show you what makes them, what destroys them, and how you can craft mouth-melting lattes.
Along the way I also settle the big debate: what is the actual difference between regular Oatly and Oatly Barista Edition!?
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Follow me on Instagram and tag me in an Instagram story
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Try Oatly Barista Edition (this episode’s sponsor) for yourself
Want to listen to more documentary podcasts about coffee? Check out my other show, Filter Stories
Go deeper into latte foam science!
Measure your latte foam’s bubble size!
Marvel at tetrakaidecahedra foam for yourself
Check out Steven Abbott’s brilliant science website
Learn how to create microfoam with Lance Hedrick
Study milk science with Barista Hustle’s online courses
Connect with my very knowledgeable guests
Steven Abbott - website
Rituja Upadhyay - LinkedIn
Nidhi Bansal - LinkedIn
Thom Huppertz - LinkedIn
Sofia Eldhe - LinkedIn
Toby Weedon - LinkedIn
The Science of Coffee is made possible by these leading coffee organisations
BWT Water and More
Marco Beverage Systems
Trabocca
Eversys
Oatly
Fiorenzato
Subscribe to A History of Coffee podcast

What kind of racing car does the Gaggia Classic GT home espresso machine remind you of? Use discount code FS202610 to get 10% off.

4) Espresso Technology Jan 03, 2023

Show notes

A good espresso is a sublime experience: rich, sweet, and wonderfully caffeinated.
But, who woke up one morning and thought to themselves, ‘I’m going to build a contraption that forces a tiny amount of super hot water with incredible pressure through a bed of very finely ground coffee’?
Well, the fact is, the first “espresso” machine built 150 years ago was awful in almost every way. Worst of all, if you gave that coffee to anybody on the street, nobody would say it’s even an espresso!
But, over the decades, problems begat solutions that begat more problems that culminated in espresso machines like Eversys that produce gorgeous espressos at just the push of a button.
And it’s got me wondering: what is the perfect espresso machine? How far can we go?
But, before clicking play, be warned: this story gets explosive and bloody!
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Please spread the word about The Science of Coffee!
Follow me on Instagram and tag me in an Instagram story
Write a review on Apple Podcasts
Leave a 5 star rating on Spotify
Learn more about how Eversys espresso machines (this episode’s sponsor) produce high quality espressos
Listen to my A History of Coffee podcast series with Prof. Jonathan Morris
Want to listen to more documentary podcasts about coffee? Check out my other podcast, Filter Stories
Pictures of the espresso machines featured in this episode
Angelo Moriondo (1884, “Big water boiler with gnarly bits”)
La Pavoni Ideale (1905, "Fire hydrant")
Gaggia Tipo Classica (1947, “Lever”)
Faema E61 (1961, “Retro 60s toaster”)
Eversys (2022, “push button”)
Want to go deeper into espresso machine technology?
Coffee Technician Guild’s Educational Courses
Barista Hustle’s The Espresso Machine course
Read Prof. Jonathan Morris’ book ‘Coffee: A Global History’
Do your own coffee museum tour in Italy!
MUMAC (Milan)
Rancilio Officina 1926 (Milan)
Accademia del Caffè Espresso (Florence)
Connect with my very knowledgeable guests
Jonathan Morris - Instagram
Hylan Joseph - LinkedIn
Giorgio Rancilio - LinkedIn
Anna Cento - LinkedIn
Carlos Gonzàlez - LinkedIn
Silvia Bartoloni - LinkedIn
Jonathan Besse - LinkedIn
The Science of Coffee is made possible by these leading coffee organisations
BWT Water and More
Marco Beverage Systems
Trabocca
Eversys
Oatly
Fiorenzato
Subscribe to A History of Coffee podcast

What kind of racing car does the Gaggia Classic GT home espresso machine remind you of? Use discount code FS202610 to get 10% off.

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