Bicarbonate
Term from the Brauwerkstatt brewing glossary, category “Brewing water and pH”.
Explanation
The substance in water that makes up carbonate hardness (HCO₃⁻). It buffers acid and so raises the mash pH. Plenty of bicarbonate suits dark beers, whose roasted malt brings acidity; for pale beers it is lowered with lactic acid or by blending with reverse-osmosis water.
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.
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.