To roast coffee faster, you need to turn up the heat….right?

No!

In this episode, we explore the three powerful methods of heat transfer that revolutionised roasting. We’ll journey from humble beginnings—when roasting three kilos took half an hour—to machines that now roast hundreds of kilos of coffee in the time it takes you to boil a kettle.

But beans roasted at lightning speed look strange, and taste… well, you’ll find out. Join us as we test-drive an industrial tangential roaster where first crack remind me of fireworks crackers.

We also see the whale-sized roaster so massive it’s worth you a Guinness World Record.

We have the technology today to roast coffee faster than ever, so why aren’t we all roasting at recording-breaking speeds?

---------------

Please spread the word about The Science of Coffee! Leave a 5 star rating on Spotify Follow me on Instagram and tag me in an Instagram story Write a review on Apple Podcasts

Discover how I make these Filter Stories episodes by subscribing to my Substack newsletter

Check out the Probat roasters mentioned in this episode:

Emmerich Spherical Roaster - "Pink Hydrant"

Large ball roaster - “Sputnik in a pizza oven”

G45 early drum roaster - “Old school steam train”

Early tangential roaster

Sample tangential roaster - "Shoebox"

Neptune 4000, the largest drum roaster in the world! - "The whale"

And there are lots of other specialty roasters from Probat I didn't have time to showcase, including their new hydrogen powered roasters. See them all for yourself!.

Theodor von Gimborn's wikipedia page

Go deeper into the science of roasting

Read Mark Al-Shemmeri’s coffee roasting blog

Do a Certificate of Advanced Studies with the Coffee Excellence Centre

Explore Barista Hustle's online roasting learning

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

Follow Filter Stories on Instagram for my infographics

Learn more about first crack on my episode Coffee Roasting, Part 1: How heat transforms coffee beans

Season 3 is made possible by these leading coffee organizations:

The Coffee Quest | BWT | TODDY | Algrano | Probat

A mother coffee plant gifts its baby everything it needs to grow—a green seed packed with food. But when we roast coffee, we hijack that gift and turn it into something else: flavor.

But what is flavor, at a microscopic level? What actually happens inside the bean when heat meets those nutrients?

In this episode, we shrink down to witness the Maillard reaction up close—a wild chain of molecular collisions that transforms baby plant food into aromas we adore.

Grab your popcorn - you’re getting a front row seat at the wildest chemistry show in coffee.

---------------

Please spread the word about The Science of Coffee! Leave a 5 star rating on Spotify Follow me on Instagram and tag me in an Instagram story Write a review on Apple Podcasts

Discover how I make these Filter Stories episodes by subscribing to my Substack newsletter

Ethiopian forest sounds curtesy of George Vlad. Hear more nature sounds here. Explore Probat's roasters

Go deeper into the science of roasting

Do a Certificate of Advanced Studies with the Coffee Excellence Centre

Grab a copy of Anja Rahn's upcoming book on coffee science through her Instagram

Explore Barista Hustle's online roasting learning

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

Follow Sebastian Opitz on LinkedIn

Follow Filter Stories on Instagram for my infographics

Season 3 is made possible by these leading coffee organizations:

The Coffee Quest | BWT | TODDY | Algrano | Probat

When I started making cold brew this last year, I treated it like hot brew filter coffee. But no matter how I adjusted the grind or tweaked the brew time, I hardly got any differences in flavor…

Then it hit me: cold brew isn’t just a slower hot brew—it’s a completely different game with its own rules!

In this episode, I speak with leading coffee researchers who break down the microscopic dance between water and coffee that explains why cold brew plays by its own playbook.

And I bring you in on the brewing secret that can turn your brews from fruit juice to nutty creaminess.

---------------

Please spread the word about The Science of Coffee! Leave a 5 star rating on Spotify Follow me on Instagram and tag me in an Instagram story Write a review on Apple Podcasts

Discover how I make these Filter Stories episodes by subscribing to my Substack newsletter Explore TODDY’s cold brewing kits

Go deeper into the science of cold brew

Do a Certificate of Advanced Studies with the Coffee Excellence Centre

Read Jiaxin (Jessie) Liang’s equilibrium extraction SCA 25 article and her published article

Discover all of UC Davis' cold brew research through the Coffee Science Foundation

Learn how to do a cold brew cupping with Toddy

Follow Filter Stories on Instagram for my infographics

Season 3 is made possible by these leading coffee organizations:

The Coffee Quest | BWT | TODDY | Algrano | Probat