Water & Mash Calculators

Water is the largest ingredient in beer by volume, and UK tap water varies enormously depending on where you live. The famously soft water of Pilsen-style regions contrasts sharply with the hard, sulphate-rich water of Burton-upon-Trent that made pale ales and IPAs legendary, or the moderately hard water of London that suits porters and stouts. The water chemistry calculator helps you adjust your brewing liquor with salts like calcium sulphate (gypsum), calcium chloride and magnesium sulphate to match a target water profile — whether you are “Burtonising” for a bitter or softening for a mild. The water treatment calculator also covers Campden tablet dosing to remove chlorine and chloramine, which most UK water companies add and which can cause medicinal off-flavours.

Mash temperature has a profound effect on your finished beer. Lower temperatures around 62-64°C produce a thinner, more fermentable wort ideal for dry bitters and session beers, while higher temperatures of 68-70°C leave more unfermentable sugars for body and sweetness in styles like Scottish heavy or sweet stout. The strike water calculator ensures your hot liquor is at the right temperature to hit your target mash temperature when it meets the grain — typically 8-12°C above the target, depending on grain temperature and mash thickness. The mash thickness calculator helps you set the right water-to-grain ratio, usually between 2.5 and 3.5 litres per kilogram for UK infusion mashing.

For more advanced brewers, the step mash calculator plans multi-temperature infusion rests for improved conversion of under-modified malts or specialty grains, while the decoction calculator works out how much thick mash to pull and boil for traditional decoction schedules. Getting your mash pH right — ideally between 5.2 and 5.6 — is one of the most impactful improvements a homebrewer can make, and the pH adjustment calculator tells you exactly how much lactic acid, phosphoric acid or acid malt to add. Use the sparge water calculator to plan your fly or batch sparge volumes, ensuring you collect enough wort without over-sparging and extracting harsh tannins.