IT’S JUST COFFEE!

An Astrophysicist Explains Your Coffee Grinder | JONATHAN GAGNÉ!

Montag, 5. Oktober 2026 · 1 h 24

MP3

Shownotes

Do bigger burrs make better coffee? Are flat burrs cleaner than conical burrs? And why can two grinds that look the same brew completely differently?

Astrophysicist and Coffee Ad Astra author Jonathan Gagné joins Rohan and Ben to unpack what grinders actually do to coffee. They get into particle size distributions, fines, burr seasoning, freezing beans and espresso flow, then tackle the coffee claims that sound certain even when the science isn’t.

If you’re new here (welcome), our show dives into some of the best coffee conversations on the internet, but we’ll always remind ourselves that at the end of the day, it’s just coffee!

CHAPTERS!
Why grinders became coffee’s big obsession
Meet Jonathan Gagné
APAX LAB
From astrophysics to Coffee Ad Astra
Are bigger burrs actually better?
Burr heat, extraction and grinder myths
Flat, conical and burr seasoning
Static, freezing beans and keeping coffee fresh
What particle size distribution really means
Why some coffees produce more fines
Should you grind coarser for filter coffee?
What the 300 grind tests revealed
How water moves through an espresso puck
Filter coffee claims that don’t hold up
Tamp pressure and puck preparation
Does “high clarity” mean better flavour?
What we still don’t know about coffee and water
How to question confident coffee claims
Where to find Jonathan

Explore Jonathan’s work: coffeeadastra.com
Jonathan on Instagram: instagram.com/jgagneastrocoffee

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Want to get in touch? Hit us up at hello@itsjustcoffeepod.com for any questions or comments.

Proudly sponsored by:
APAX LAB: apaxlab.com

Thanks for listening!

#ItsJustCoffee #JonathanGagné #CoffeeAdAstra #CoffeeGrinders #CoffeeScience

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