Westmalle Abbey, Belgium. Moderately hard water with moderate residual alkalinity - suited to amber and brown beers, with a chloride-forward balance that rounds out the malt.
| Ion | ppm |
|---|---|
| Calcium (Ca²⁺) | 41 |
| Magnesium (Mg²⁺) | 8 |
| Sodium (Na⁺) | 16 |
| Chloride (Cl⁻) | 62 |
| Sulfate (SO₄²⁻) | 26 |
| Bicarbonate (HCO₃⁻) | 91 |
| Brewing numbers | |
|---|---|
| Total hardness (as CaCO₃) | 135.3 ppm |
| Alkalinity (as CaCO₃) | 74.6 ppm |
| Residual alkalinity (as CaCO₃) | 40.7 ppm |
| Sulfate-to-chloride ratio | 0.4:1 |
Salts to add to reverse-osmosis or distilled water, calculated by the BrewWaterSolver solver with the most common homebrew salts.
| Salt | 5 gal (18.9 L) | 20 L |
|---|---|---|
| Calcium chloride (CaCl₂) | 2.26 g | 2.38 g |
| Epsom salt (MgSO₄) | 1.25 g | 1.32 g |
| Chalk (CaCO₃) | 0.75 g | 0.79 g |
| Baking soda (NaHCO₃) | 0.99 g | 1.05 g |
Closest match with these salts; it can't reach Ca 51.3 ppm vs 41 exactly.
Chalk (CaCO₃) doesn't dissolve well directly in mash or sparge water without dissolved CO₂ - slurry it in carbonated water (e.g. sparkling water) before adding it, rather than mixing it into still water or sprinkling it in dry, or the calculated amount may not fully dissolve. How to dissolve chalk with CO₂
Stan Hieronymus, Brew Like a Monk (Brewers Publications, 2005) - BrewWaterSolver's Ca/Mg/Na/SO4 (41/8/16/26) match the book's published Westmalle figures exactly; Cl (62 here vs. 60 published) is a minor rounding difference.