An Insight about different espresso recipes
by charting the first derivative of the puck resistance
“Puck resistance” is a concept I added to the DE1 a few months ago, but we've been struggling a bit to understand what to do with the information.
for those that like mathematics, it is FYI calculated as:
pressure / (flow ^ 2)Collin Arneson yesterday posted an interesting writeup arguing for the 1st derivative of the puck resistance number. This is a chart of the change in puck resistance.
This number shows us when puck integrity falls apart, regardless of flow rate or pressure changes that might obscure that trend.
What I found interesting was that it's also a way to compare espressos recipes.
Those recipes that result in linear puck degradation should make better tasting.
The author's tests with Rao's Blooming seems to confirm this. Pucks hold up better after a 30 seconds bloom, and degrade in a cleaner fashion.
-john
Updated 2020/07/30