Alkalinity
Term from the Brauwerkstatt brewing glossary, category “Brewing water and pH”.
Explanation
The bicarbonate content of the water, given in mg/l (ppm) as CaCO₃. It buffers acid and raises mash pH.
Work it out yourself
Brewing water calculator – Adjust your tap water to the beer style: the calculator tells you how much calcium chloride, gypsum and lactic acid you need.
Test your knowledge
What does the residual alkalinity of brewing water describe?
- How much chlorine the water contains
- How strongly the water raises the mash pH
- How warm the water is
Show answer
Correct: How strongly the water raises the mash pH. High residual alkalinity suits dark beers; for pale beers it is lowered with lactic acid or soft water.
Frequently asked questions
Do gypsum and calcium chloride raise alkalinity?
No. The salts add calcium, sulphate and chloride, but no bicarbonate. Alkalinity stays the same; general hardness rises. In the mash, the calcium does lower residual alkalinity.
Alkalinity target or beer colour, which should I use?
Both aim for the same result, a mash pH of about 5.4–5.5. The fixed alkalinity target is simple; beer colour takes calcium into account and often saves a little lactic acid. The measured mash pH is what counts.