Brewing water and pH
Hardness, salts, pH and water treatment. 16 terms.
Alkalinity
- The bicarbonate content of the water, given in mg/l (ppm) as CaCO₃. It buffers acid and raises mash pH.
Baking soda
- Sodium bicarbonate, sold as plain baking soda without additives. It raises mash pH when it is too low, for example in dark beers brewed with soft water. Use it sparingly, as it adds sodium to the beer.
Calcium
- The most important mineral in brewing water. In the mash it lowers pH, helps the enzymes and the yeast and makes the beer clearer. Usually 50–150 mg/l is ideal. Gypsum and calcium chloride add calcium.
Calcium chloride
- Brewing salt that adds calcium and chloride. Chloride makes the beer fuller and rounder.
Campden tablet
- Potassium metabisulphite that removes chlorine and chloramine from tap water. One tablet treats about 75 L (about 19.8 gal): crush it, stir it in and wait 10–15 minutes. Only needed if the water smells of chlorine.
Chloride
- Emphasises the malt and makes beer rounder and fuller. 50–100 mg/l is common. Calcium chloride adds chloride. Not to be confused with chlorine from the water supply.
Chloride to sulphate ratio
- Shows whether the water brings out the malt or the hops. More chloride than sulphate (e.g. 2:1) suits malty beers, more sulphate than chloride (e.g. 1:2 to 1:3) hoppy ones. Around 1:1 is balanced.
Dilution
- Mixing tap water with distilled water to lower values that are too high.
General hardness (GH)
- Calcium and magnesium in the water. Gypsum and calcium chloride raise it, while alkalinity stays the same.
Gypsum
- Calcium sulphate. Adds calcium and sulphate. Sulphate accentuates hop bitterness and makes the beer drier.
Lactic acid 80 %
- Lowers alkalinity and pH. Added to the cold brewing water or, as a correction, to the mash. Corrosive, wear gloves.
Magnesium
- Usually present in tap water in small amounts and a nutrient for the yeast. 10–30 mg/l is enough. Too much tastes harsh and unpleasantly bitter.
Mash pH
- pH of the mash 10–15 minutes after mashing in, measured at 20 °C (68 °F). Usually aim for 5.4–5.5. It affects efficiency, clarity and how smooth the hop bitterness tastes.
Residual alkalinity (RA)
- What is left of the acid buffer once calcium and magnesium work against it in the mash: RA = alkalinity − (Ca / 1.4 + Mg / 1.7), all in mg/l (alkalinity as CaCO₃). It shows how strongly the water raises mash pH overall.
Sulphate
- Emphasises hop bitterness and makes beer drier and crisper. Plenty of sulphate suits pale ale and IPA (150–300 mg/l), little suits Helles, Kölsch and wheat beer. Gypsum adds sulphate.
Water report
- The values of your tap water. Most water suppliers publish them on their website, usually including calcium, magnesium, bicarbonate or alkalinity, sulphate and chloride. Enter these values in the brewing-water calculator. Alkalinity is best measured yourself on brew day with a drop test kit.