Coffee Data Science

Coffee Roast Metrics while Aging

Metrics over a a few weeks

Robert McKeon Aloe
3 min read4 days ago

I wanted to better understand how coffee changes as it rests, and I had some metrics we normally use to look at roasts from a quantitative view. I used two devices:

  1. Syncfo 4in1
  2. DiFluid Omix

Over a few weeks, I measured a few metrics:

  1. Color (whole bean and ground coffee)
  2. Density
  3. Moisture
  4. Water Activity (only on the DiFluid Omix)

I also measured over three test roasts dropping at a few different points:

  1. First Crack (FC)
  2. FC+1 minute
  3. FC+2 minutes

Whole Bean Color

Starting with whole bean, there are some changes in the color, but there is not a clear pattern.

The same was true for FC+1 and FC+2.

Ground Coffee Color

Ground coffee told a different story. I ground 10g of each roast, and then I measured the coffee color at the noted intervals. I stored these grounds in a sealed container. For the FC roast, the color dropped from 112 to 107 for the Syncfo and 107 to 102 for the DiFluid.

This drop in color did not happen for the FC+1 roast or the FC+2 roast.

Bean Density

Bean density seemed to go up slight for the FC roast, but I am not quite sure the error rate on the measurement.

Density didn’t change for the FC+1 or FC+2 roasts.

Moisture

For the FC roast, there was a slight increase.

For the FC+1 and FC+2 roasts, there was no change.

Water Activity

Water activity started low and went up until around 6 days.

I am not sure why the +12H jumped and then goes back down at +1D, but that was the correct measurement.

Overall, there does not seem to be many measurable changes across time for coffee aging except maybe the FC roast. I am also very curious about the water activity level increasing.

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Further readings of mine:

My Second Book: Advanced Espresso

My First Book: Engineering Better Espresso

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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.