Coffee Data Science
Added Moisture to Green Coffee Beans Feasibility
More experiments for an older variable.
I have experimented with adding moisture to coffee before. I have generally found it to be beneficial, but I had difficulties refining the variable of how much and how long of a roast. However, with the Roest, I have better control, so I want to explore that area again, starting with a feasibility data collection:
- Baseline
- +3% Moisture
- +6% Moisture
Post-Roast Metrics
I ended all three roasts at 212 C bean temperature, and the roast metrics were pretty close.
The coffee color had some variance, but it was close enough for my tests to understand how the moisture variable was impacting taste.
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).
Shot Data
I pulled four shot pairs to build intuition, and +6% won in every test, and I also note that +3% also beat the baseline in each set.
There was little impact on EY, but maybe a larger dataset would be more revealing.
This data shows good signal for more moisture, so my next test will increase the moisture range to see if I can find something more optimal. I also wonder if it is a question of increasing moisture to a certain percentage across beans or only increasing the moisture of the green beans by some set percentage.
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Further readings of mine:
My Second Book: Advanced Espresso
My First Book: Engineering Better Espresso
