Coffee Data Science

Coffee Grind Rate: Initial Measurements

A curious test

Robert McKeon Aloe
2 min readSep 13, 2024

From prior tests, it is known that the particle distribution and particle shape changes during the grind. However, I have not seen data on the rate of grind, so I took a small amount of data to better understand the variable of grind rate.

I used the Acaia Pyxis and their app to measure weight throughout the grind. This feature was initially intended to weigh a brew while brewing coffee.

I looked at the Niche Zero, the Zerno, and the SKP85.

Niche Zero

The Niche has conical burrs with an angle offset to the table, and the output very much matched a near constant output.

Zerno

The Zerno has flat burrs perpendicular to the table it sits on, and the grind rate was not linear but a decay.

A polynomial fit aligns well with the data.

SKP58

The SKP58 has conical burrs parallel to the table, and it performed similarly to the Niche.

I’m curious how these rates change based on the angle of the burrs.

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Further readings of mine:

My Second Book: Advanced Espresso

My First Book: Engineering Better Espresso

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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.