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What it does :
Gypsum is used to lower mash pH.
What it is:
This is the common name for calcium sulfate.
How it works:
Gypsum lowers the mash pH and also helps particulates to settle out of solution.
Use of 1 teaspoon per 5 gallons adds 140 ppm of sulfate and 60 ppm of calcium. Add to the water when mashing for all-grain brewing, or just before the boil.
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