This calculator works out which brewing salts, and how much of each, to add so your source water moves toward a target ion profile. Enter your starting water and a target, and it returns gram weights of the six common salts plus the resulting profile and sulfate-to-chloride ratio.
How it works
Each salt dissolves to contribute a fixed amount of specific ions, expressed as ppm added per gram of salt per gallon of water:
| Salt | Adds (ppm per g/gal) |
|---|---|
| Gypsum (CaSO4·2H2O) | Ca +61.5, SO4 +147.4 |
| Calcium chloride (CaCl2·2H2O) | Ca +72.0, Cl +127.4 |
| Epsom salt (MgSO4·7H2O) | Mg +26.1, SO4 +103.0 |
| Table salt (NaCl) | Na +103.9, Cl +160.3 |
| Baking soda (NaHCO3) | Na +72.3, HCO3 +191.0 |
| Chalk (CaCO3) | Ca +105.8, HCO3 +158.5 |
To move from source to target, the tool solves greedily: it uses calcium-and-bicarbonate salts to raise alkalinity, gypsum and Epsom for sulfate, calcium chloride and table salt for chloride, then reports the resulting profile. Because salts add ions in pairs, you usually cannot match every target exactly — the tool shows the achievable profile so you can judge the trade-offs.
Classic target profiles (ppm)
| Profile | Ca | Mg | Na | SO4 | Cl | HCO3 | Suits |
|---|---|---|---|---|---|---|---|
| Pilsen | 7 | 2 | 2 | 5 | 5 | 15 | Pale lager |
| Dublin | 118 | 4 | 12 | 55 | 19 | 160 | Stout |
| Burton | 295 | 45 | 55 | 725 | 25 | 300 | Hoppy ale |
| Munich | 75 | 18 | 10 | 10 | 2 | 200 | Dark lager |
| Balanced | 80 | 5 | 15 | 100 | 100 | 40 | All-rounder |
Worked example
Starting from distilled water (all zero) and targeting a balanced 5-gallon batch with Ca 80, SO4 100, Cl 100:
- Gypsum for sulfate: ~3.4 g raises SO4 by ~100 ppm and Ca by ~42 ppm.
- Calcium chloride for chloride: ~3.9 g raises Cl by ~100 ppm and Ca by ~57 ppm.
- Combined calcium ≈ 99 ppm — close to target, with a 1:1 sulfate:chloride ratio.
Tips and notes
- Always start from a water report or use RO/distilled water for predictable results. You cannot remove ions with salts — only add them.
- The sulfate-to-chloride ratio is the single most useful number here: push it high for crisp, hoppy beers and low for round, malty ones.
- Add calcium salts to the mash for the pH and enzyme benefits; chloride and sulfate flavor effects carry through whether added to mash or kettle.
- Chalk dissolves poorly in practice — for alkalinity, baking soda is usually more reliable, or use acid to lower pH rather than chalk to raise it.