Coffee Data Science
A Toothbrush for Coffee?
Improving ultrasonic mixing
Awhile back, I added an ultrasonic mixer (beer foamer) to my espresso routine. I found mixing the drink after brewing improved flavor, particularly bitter and sour flavors. This change in routine was inspired by research in the past few years into using ultrasonics, sound waves, or electricity to modify the taste of coffee after being brewed.
However, I had a problem: my beef foamer broke. So I had used tape and a rubber band to keep it going.
Then I decided to try an ultrasonic toothbrush instead, and I compared it to my beer foamer.
Metrics of Performance
I used two sets of metrics for evaluating the differences between techniques: Final Score and Coffee Extraction.
Final score is the average of a scorecard of 7 metrics (Sharp, Rich, Syrup, Sweet, Sour, Bitter, and Aftertaste). These scores were subjective, of course, but they were calibrated to my tastes and helped me improve my shots. There is some variation in the scores. My aim was to be consistent for each metric, but some times the granularity was difficult.
Total Dissolved Solids (TDS) is measured using a refractometer, and this number combined with the output weight of the shot and the input weight of the coffee is used to determine the percentage of coffee extracted into the cup, called Extraction Yield (EY).
Data
I looked at 12 shot pairs, and all but one were better or matching the baseline beer foamer.
This toothbrush ultrasonic tool improved across all taste metrics.
The shot pairs had similar TDS and EY, so they were similarly brewed.
Using a two-tailed paired t-test, the TDS and EY were not statistically different. The difference in taste was statistically significant.
This small study helped qualify a new tool that is much easier to come by. The original beef foamer went out of stock, but luckily, there are many ultrasonic toothbrushes waiting to be dipped into coffee.
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
