Gypsum will reduce the wort pH, improve malt extraction efficiency, balance hop flavors, improve wort clarity and remove phosphates and proteins from the wort trub.
Gypsum is also known as Calcium Sulfate, CaSO4. It is the main component of Burton Water Salts. It will add a permanent hardness to the brewing water, and is commonly used when making water adjustments especially when using distilled or Reverse Osmosis (RO) water.
Usage: 1 tsp per 5 gallons