Coffee Data Science

Dye Colored Espresso Shots

Adding dye to espresso shots

Robert McKeon Aloe
4 min readApr 23, 2021

In the Before Times, I was looking at different ways to understand flow during the shot. If only there was a way to see how the water went through the puck. It suddenly dawned on me that I could try color dyes.

For those uninterested in words, dyes were not particularly effective, and I ended up drinking an unsafe amount of dye and ended up with a bad stomach pain. My friends were surprised I was drinking the shots. I dumped the last one.

First Test

I used four different dyes around the shot.

The colors were similar to each other so it was a little difficult to see the orientation.

The post-shot puck was colorful, but I didn’t see anything particularly interesting.

Second Shot

I had been pulling 14g shots in a 7g basket so as to remove the headspace of the filter. Many of these were staccato shots.

The one thing I noticed during the shot is that the colors stayed in about the same spatial spots. So there wasn’t any crazy lateral movement or channeling.

Third Shot

More color!

This shot went one-sided on me.

Fourth Shot

More colors plus a red dot.

Again, I didn’t see anything interesting even in the post puck.

Overall, this experiment was regrettable because I drank all the shots and got sick from all the dye. It would have been more worth it if I had found something interesting.

Maybe I’ll design another dye experiment for another day but not drink the shots.



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.