Coffee Data Science

Simple Clumps and WDT Test: Espresso

Messing around and finding out

Robert McKeon Aloe
3 min readJan 28, 2022

My grinder (Niche Zero) doesn’t cause clumpy coffee, but that might be due to living in a dry region. However, I was curious about running an extreme clump test with and without the WDT method.

I was hesitant about wasting perfectly good coffee so such a test, so I used a spent puck. This had plenty of clumps, so it seemed like it might make for a good test.

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After tamping, it was pretty ugly.

Then I made a shot where I broke up the clumps thoroughly with WDT.

I pulled them both, and the WDT spent puck had more even water flow. For the clumpy puck, it was a hot mess. It quickly donuted.

From the foam in the cup, the WDT seems more homogenous with a bit higher flow rate.

This was a quick test to mess around and find out. I typically don’t need WDT especially if I’m making a staccato shot, and I’m glad the extreme clumping exampled played out as expected.



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.