Calcium Sulfate (CaSO₄) Gypsum - Brewing Water Treatment & Mineral Addition
Calcium Sulfate (CaSO₄), universally known among brewers as gypsum, is a food-grade brewing water mineral used to build and fine-tune the mineral profile of brewing water with precision and repeatability. One of the most widely used and well-understood brewing salts in the homebrewer’s water chemistry toolkit, gypsum dissolves cleanly in strike water, sparge water, or directly in the mash — delivering an immediate and measurable increase in both calcium and sulfate ion concentrations that fundamentally shapes the bitterness character, dryness, and hop perception of the finished beer.
What makes calcium sulfate the go-to mineral addition for hop-forward brewing is its powerful effect on two of the most impactful dimensions of beer flavour. The calcium ion (Ca²⁺) supports healthy mash enzyme activity, promotes yeast health and flocculation, lowers mash pH, and improves beer clarity and long-term stability — making it an essential addition across virtually all brewing styles regardless of hop character goals. The sulfate ion (SO₄²⁻) is where gypsum earns its reputation in the hop-forward brewing world: sulfate accentuates perceived hop dryness, sharpens bitterness, and gives the finish a clean, mineral-edged crispness that defines the classic Burton-on-Trent pale ale character and the dry, assertive bitterness of West Coast IPAs and American Pale Ales.
Used alongside calcium chloride, magnesium sulfate, and sodium chloride, calcium sulfate gives homebrewers the granular control over water chemistry that makes it possible to build the water profile the style demands — not just brew with whatever comes out of the tap.
Powder form
Supplied as a fine, free-flowing powder. Dissolves quickly and completely in cold or warm brewing water without pre-treatment or heating.
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Key Features
• Food-grade calcium sulfate (CaSO₄) — brewing gypsum
• Dual mineral contribution — calcium (Ca²⁺) and sulfate (SO₄²⁻) ions
• Accentuates hop dryness, bitterness perception, and mineral crispness
• Supports mash enzyme activity, yeast health, and beer clarity
• Lowers mash and beer pH — essential for water profile building
• Fine powder form — dissolves instantly in brewing water
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Usage
Best suited for: Hop-forward water profiles, Burton-style pale ale water builds, dry and bitter finish styles, general calcium supplementation across all styles
Typical styles: West Coast IPA, American Pale Ale, English Bitter & ESB, Burton Pale Ale, Dry Stout, dry lager styles
Dose: Add to strike water or mash according to target water profile. Always calculate additions against your base water report using brewing software.
Note: High sulfate levels (above ~150 ppm) can accentuate harsh or rough bitterness in some styles. Keep within recommended water profile targets for the style you are brewing.
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Quick facts
Product: Calcium Sulfate
Common name: Gypsum
Chemical formula: CaSO₄
Form: Fine powder
Ion contribution: Calcium (Ca²⁺) + Sulfate (SO₄²⁻)
Use: Water chemistry adjustment, hop accentuation, mash pH, yeast health, beer clarity