Coffee Data Science
Roast Analysis: Fast, Medium, Slow, and Baked
Analyzing some roast data
Recently, there was a paper looking at how roasting affects taste. They had quite a bit of data, but most of the data was presented as tables. I wanted to see what was valuable out of that data, so I plotted it for your benefit and mine.
They looked at four roast variants: fast, medium, slow, and baked. They started with tasting notes and then moved onto chemical analysis.
Tasting Metrics
There is a change in scores over these roasting variants. Astrigency and body seem less affected, but other metrics have a wide variation. Baked roasts don’t come off as sweet or clean.
Chemical Compounds
They looked at a variety of compounds, and the most well known are presented here in two forms.
Many had very similar chemical measurements, so I’m not sure what conclusions one can draw except for how much acidity changes between baked and fast roasts.
They look looked at more compounds, but the units varied greatly.
I grouped them and adjusted the units of measurement so you could see trends. Alcohols increase slight as the roast becomes more baked. This trend is the opposite for most Aldenhydes.
For acetic acid, the trend is clearer, but it is not so clear for the Furans.
There isn’t really a story in Ketones.
The trends for Pyrazines are interesting because they peak mostly in the Medium or the Baked.
The other components did not say much either.
I enjoy all this data being available, but I wish the authors had visualized it better so it would easier to capitalize on this data. What this data clearly shows is how much roast speed can affect the chemical composition and taste of coffee, which is new to roasters. I enjoy quantifying how it modifies the outcome of the roast, and I’m interested to see how to use that information to my advantage.
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