Coffee Data Science

Wave vs SSP Burrs for Espresso: Particle Shape

Part 2

Robert McKeon Aloe
2 min readFeb 4, 2025

Previously, I found the Wave burrs under-performed SSP burrs, so I wanted to dive deeper to understand why. I suspect particle distribution and shape could tell an interesting story about the differences in the two burr sets.

These were the Wave Burr 64mm Espresso set.

SSP burrs on top, wave burrs on the bottom.

I looked at a few grind settings for the Wave. The Wave grind setting is negative because I didn’t adjust the zero value for the SSP burrs. The zero setting was around -375 for the Wave. -200 is the finer setting, and -150 is the coarser setting.

I couldn’t quite find a grind setting to match SSP 200. I would say -175 is the closest, which when adjusted for zero offset, should be a 200 um gap.

We can look at particle shape using LBP and K-means clustering. The result is being able to compare the same binning of particles created by each RPM. This gives a little more clarity. Particles under 100 um are very different in shape.

Particles 500 um in size also have an interesting pattern because all the settings are not similar.

Burrs are wild. We don’t have a good idea of what burr shapes cause what particle shapes and how that impacts flavor (or at least publicly available information). I’m excited to add some information to the currently public data. I hope to see more and a greater understanding.

If you like, follow me on Twitter, YouTube, and Instagram where I post videos of espresso shots on different machines and espresso related stuff. You can also find me on LinkedIn. You can also follow me on Medium and Subscribe.

Further readings of mine:

My Second Book: Advanced Espresso

My First Book: Engineering Better Espresso

My Links

Collection of Espresso Articles

A Collection of Work and School Stories

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Robert McKeon Aloe
Robert McKeon Aloe

Written by 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.

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