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Photo by Noé Aubin-Cadot

This page is dedicated to methods and data to improve the preparation of pour over coffee

Coffee Blog

This is where you will find all of my previous blog posts about coffee.

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The Grind Size Application

I wrote a computer application to analyze the particle size distribution of your grinder based on photographs or scanner images

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Water for Coffee

In most cities, tap water damages the taste of coffee, even when the water tastes great by itself.

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Photo by Kathy Gagné

Patreon

If you would like to support this blog, I have a Patreon page that allows me to purchase measurement devices and brewing equipment. It comes with early access to my latest blog post, and extra posts about my favorite roasters, brew logs and latest news.

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Flavor Wheels by Variety

I used data from the Firstbloom app to build visualizations of flavor by origin and variety

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The Coffee Gear I Use

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About me

I’m a researcher in astrophysics at the Montreal Rio Tinto Alcan Planetarium, and an adjunct professor at Université de Montréal – I write about my science projects here. I love to think about coffee brewing and use the tools of science to learn how to brew better coffee. Hopefully, you will find on my blog some things that are also useful to you.

Photo by Scott Rao
Photo by Scott Rao

I also write about astrophysics

I write about my latest science projects on the topics of young stars, brown dwarfs and exoplanets

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Coffee ad Astra

by Jonathan Gagné

Most photos on this website are by Noé Aubin-Cadot

Website logo by Daniel Demay

I just published a blog post on my Patreon going deep into the analysis of 300 particle size distributions for 24 espresso grinders, with a number of observations that they allowed me to make. This was super informative to me and I hope it also is to all of you ! https://www.instagram.com/reel/CjBluEDD8JL/ I'm happy to announce I have teamed up with @flairespressomaker and @weberworkshops for a nice giveaway this week; you can win a Flair 58 + Weber Workshops Unifilter along with my book 🙂 follow the link in my bio to enter the giveaway ! I just published a new blog post on my Patreon (link in bio) about particle size distributions, with a discussion of how burr spacing, rpm, burr geometry affects them, and how to characterize different styles of particle size distributions. This is one of my most data heavy posts so far, thanks a ton to @weberworkshops for sharing their data. I just posted a new blog post on my Patreon (link in bio) about my updated understanding of the mechanisms that I believe cause astringency in coffee, with hints about avenues we might use to reduce it. The post is immediately available on Patreon and will become publicly available in about 2 weeks ! @pullandpourcoffee created yet another awesome visual to convey some of my recent understandings of espresso physics ! I think this phenomenon has often been misconstrued as puck erosion or degradation, whereas this will happen in even the most well behaved espresso shots ! I will be teaching my second class on the physics of coffee during WOC Milan this summer ! The class will be on June 24, 8-11 AM in a beautiful room owned by @bwtglobal. I'm excited to announce I will give a 3-hours live class on the Physics of Coffee during the 2022 Specialty Coffee Expo in Boston ! Here is yet another beautiful infographic created by @pullandpourcoffee, based on a graph from my book The Physics of Filter Coffee. This graph shows how the height of your kettle, and the pour rate affect agitation, which in turn affects extraction, clogging and flow evenness in pour over coffee. My personal preference is to generally stay just below the breakup height (the height at which you start hear splatter sounds) to maximize turbulence which can be seen as random small-scale motions in the slurry. This encourages each coffee particle to encounter water, but can also cause filter clogging with some grinders or coffees that produce more fines. My strategy when that happens is to pour a bit slower and still stay just below the breakup height. If you still experience clogging issues, it can be worth exploring pouring from much lower than the breakup length.