I'm using gypsum for the first time in an IPA I will be brewing in a few days. Today I was making the starter and thought:
Since it's a hopped starter, why not add a pinch of gypsum?
In the end I used PDME and yeast nutrient along with 2g Columbus hops and a tiny pinch of gypsum.
As I usually do with anything I brew, I drew a very small sample to smell and taste it. When I tried I was blown away by the salty taste. Does this come from the yeast nutrient? Or from the gypsum?
I've done some calculations for the total ppm of Calcium and sulfate that I am after, but if only a pinch of gypsum already made my 2L starter that salty, maybe I need to re-think.
Should gypsum additions be calculated using final water volumes (batch size) or total water volumes? I was going to use 33g of gypsum to obtain 191 mg/L Calcium and 460 mg/L sulfate in 43.4L (total brewing volume). Those figures include additions from the city water supply.