Random Musings of a Coffee Technologist
While the shop was closed on Monday I took the opportunity to play with the new coffee refractometer that I picked up at the SCAA conference in Houston to replace my trusty old (but requiring far too much sample preparation time to really be useful anymore) electrical conductivity TDS meter. I’ll be doing a series of similar tests as I have time and doing a proper writeup when everything is done, but today I did some analysis of the numbers, plugged them into BrewPlot, and produced this chart showing how strength and extraction change in relation to the prewet setting on my Fetco Extractor.
Brewing parameters: 0.34 pounds coffee (Sumatra Mandheling, all batches from the same roast), 3.25L water (6.44 pounds hot water if coffee isn’t brewed), 4 minute brewing time, 20 second prewet delay, 202 degree F water temperature.
As for flavor, I liked the taste of the 5% prewet best.

While the shop was closed on Monday I took the opportunity to play with the new coffee refractometer that I picked up at the SCAA conference in Houston to replace my trusty old (but requiring far too much sample preparation time to really be useful anymore) electrical conductivity TDS meter. I’ll be doing a series of similar tests as I have time and doing a proper writeup when everything is done, but today I did some analysis of the numbers, plugged them into BrewPlot, and produced this chart showing how strength and extraction change in relation to the prewet setting on my Fetco Extractor.

Brewing parameters: 0.34 pounds coffee (Sumatra Mandheling, all batches from the same roast), 3.25L water (6.44 pounds hot water if coffee isn’t brewed), 4 minute brewing time, 20 second prewet delay, 202 degree F water temperature.

As for flavor, I liked the taste of the 5% prewet best.