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.
What the calculator works out
You enter your water report: alkalinity, pH, calcium, magnesium, sulphate and chloride, plus the amounts of tap water and distilled water and your grain bill.
Then you set targets: chloride and sulphate decide whether a beer tastes soft and malty or dry and bitter, and alkalinity affects the mash pH. From this the calculator works out the salt additions of calcium chloride and gypsum, and the amount of lactic acid needed to lower the alkalinity.
How to use it
1. Look up your water values from your water supplier or measure them, and enter them.
2. Choose targets to suit the style: more sulphate for pale, hoppy beers, more chloride for malty and hazy beers.
3. Weigh out the salts and lactic acid carefully and add them to the brewing water.
4. Measure the mash pH after mashing in (cool the sample to 68 °F / 20 °C / 68 °F). The target is usually 5.2 to 5.6.
Good to know
All values can be shown in US units, for example ppm instead of mg/l. The calculator remembers your entries in your browser, so you don’t have to start from scratch for the next batch.