Coffee Data Science

Does Espresso Extraction Produce More Fines?

Let’s find out!

Robert McKeon Aloe
2 min readNov 15, 2022


On Instagram, I had a discussion about fines in the cup, and someone asked if I knew or had data to address if the espresso process could break up coffee grounds to produce more fines. I didn’t have data, but I felt like it was a simple experiment.

First, I ground coffee on a coarse setting, and I used the Fellow Shimmy to remove particles less than 300um. Then I pulled a long shot.

I dried the puck so I could sift the spent coffee.

I used the Kruve sifter and a 500um scren. The majority were greater than 500um, and a small amount of grounds made it into the cup.

I measured the particle distributions afterwards. The particles less than 500um had a very tight distribution with few particles less than 300um.

The challenge with this experiment is that coffee grounds will lose their mass during extraction, so I felt like a needed a better design of experiment. Super fine particles weren’t produced or measured in this experiment, but I wanted to be sure.

Stay tuned for Part 2.

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Robert McKeon Aloe

I’m in love with my Wife, my Kids, Espresso, Data Science, tomatoes, cooking, engineering, talking, family, Paris, and Italy, not necessarily in that order.