Brewing Water Calculator
Brewing Water Calculator
Turn the figures on your water company's hardness report into brewing salt additions. Enter your tap water, pick a target style profile, and the calculator works out the salts to add.
Before any salt maths, deal with the chlorine. A campden tablet (sodium or potassium metabisulphite) removes both chlorine and chloramine — a quarter of a tablet does 25 litres of tap water. Boiling or standing overnight removes chlorine but not chloramine. Campden changes nothing else: hardness and alkalinity are untouched.
| Salt | g / batch |
|---|
No additions needed — your water already meets or exceeds this target.
| Ion | Before | After salts | Target | Result |
|---|
Salts can only raise ions. Your water is above target on the highlighted rows — switch to advanced mode to reduce them with dilution or acid.
How to use
Find your postcode's hardness report on your water company's website (look for "water quality" or "hardness"). Copy the calcium, magnesium, sodium, chloride, sulphate and alkalinity figures into the tap-water boxes — use the unit dropdowns to match however your company reports them. Pick a style profile, and weigh out the salts shown into your brewing liquor.
The water is only part of the mash pH story. A pale grist in distilled water lands around pH 5.7–5.8, roasted malts near 4.6, and the alkalinity in a hard UK supply adds roughly 0.1–0.3 on top. The pH shift shown is that water contribution, measured at 4 litres per kilo of grain; a thinner mash shifts more, a thicker one less. A pH meter on the day beats any prediction.
The sulphate : chloride ratio is the conventional way to describe a profile — sulphate forward for pale, bitter beers, chloride forward for malt-led ones. Brewers have worked to it for a century; blind tastings have not settled how much of the flavour effect is real, so treat the labels as tradition rather than a guarantee.
Profile figures follow Palmer & Kaminski's Water; other authors publish slightly different numbers for the same cities.