Calcium Sulphate (gypsum)

Calcium sulfate is often used as a source of calcium ions and is generally used in brewing British pale ales and bitters. Calcium sulfate treatment is sometimes referred to as "Burtonization" (after Burton-on-Trent in England) because Burton-on-Trent waters are rich in gypsum and this area is world-famous for its pale ales.

Used to harden the water when mash brewing.

Lowers pH. Useful for adding calcium if the water is low in sulfate. Can be used to add sulfate 'crispness' to the hop bitterness