A directory of my articles by topic

This is a collection of collections of stories. I have stories on espresso, work, school, myself, my family, LEGO’s, and Photography. I hope this page helps navigating my list of stories.

A Collection of Espresso Articles

A Collection of Work and School Stories

Personal Stories and Concerns

LEGO Story Splash Page

Photography Splash Page


Coffee Data Science

An experiment started by a toddler

The other day, my toddler got a chair and started messing around with my superautomatic espresso machine. By the time the machine ran out of water, there were two extra long shots in one cup. I didn’t want to drink it because it was very diluted, so I thought why not evaporate some of the water?

Why not take some measurements?

It turns out that using a toaster oven to dry out a shot takes too many hours.


Coffee Data Science

Controlling for flow

Coffee extraction still seems a mystery especially when for each coffee, one has to dial-in a grind for espresso. I’m left with a few questions, and so I set out to understand how extraction is connected with grind setting.

Is there a fundamental extraction limit per grind setting?

Now some might say we already know, in general, that a finer grind can get a higher extraction, but as grind gets finer, the probability of channeling increases such that overall extraction may decrease. To get the highest extraction, you would want the finest grind with the least channeling.

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Thus, to even…


Coffee Data Science

A curious adventure

Coffee ground distributions can be informative for coffee grinders and dialing-in espresso shots. The typical methods are expensive, namely sifting and laser diffraction. Jonathan Gagné made an image based method, and for awhile, one had to compile the code and have a Python environment handy. I typically don’t, so I built my own.

Recently, someone made an exe file allowing one to run Jonathan’s method on their computer without setting up their enviroment, so I did that to compare his method to my method.

We use different thresholds. Jonathan uses a simple threshold, and I use an adaptive threshold in…


Coffee Data Science

Sifting for an answer

Fines migration is a concept in espresso that doesn’t have much supporting evidence, but the idea persists.The main concept is that very fine particles less than 100um migrate to the bottom of the puck during the shot. In the process, they not only come out of the puck into the coffee, but they clog the filter basket holes.

I have previously presented data using chalk to show that fines don’t migrate far, and I have presented some data to suggest that coffee swells which would block the migration of fines. …


Maybe just wash them.

Typically, when I roast coffee, I roast two different beans separately. It makes for a much better blend post-roast except when you knock over your basket because you weren’t paying attention.

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I was really sad and emotional even though in terms of cost, it was $4, and in terms of time, it was 15 minutes. However, I don’t like wasting anything.


Coffee Data Science

Explorations outside the bounds of mainstream

Previously, I have experimented using spent coffee grounds before to give a controlled variable in order to test a theory about coffee also being able to filter itself. However, the trouble is that spent grounds don’t behave like fresh grounds, and I don’t fully understand how to get to really good spent grounds.

I’ll explore here how I got a pretty decent set of spent grounds, and these grinds will be the basis of some experiments to understand coffee better.

Desired Attributes

Good spent grounds should be able to be used in an espresso basket and have a similar shot as good…


Coffee Data Science

Using some data lying around

I am a fan of a short and strong shot of espresso. However, as I see others pulling longer shots, I wonder how my shots compare to theirs in terms of Extraction Yield (EY). EY correlates well to taste for me, and in general, EY has been used to quantify espresso shot quality. I wanted to know if EY from the first half of a shot predicts well what the final EY would be. Luckily, I had some data.

I collect Total Dissolved Solids (TDS), which is used to calculate EY, and for awhile, I was collecting this measurement for…


Coffee Data Science

Adding dye to espresso shots

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.

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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