Water makes up over 90% of beer, yet most homebrewers pay it little attention. The mineral composition of your brewing water directly shapes hop perception, malt character, mouthfeel, and fermentation behaviour.
The six ions that matter
Calcium (Ca) is the workhorse ion. It promotes enzyme activity in the mash, aids yeast flocculation, and improves beer clarity. Most brewing styles want at least 50 mg/L.
Magnesium (Mg) is a yeast nutrient in small amounts but contributes a harsh, astringent bitterness above 30 mg/L. Keep it moderate.
Sodium (Na) rounds out malt flavour and adds body at 10–70 mg/L. Above 150 mg/L it tastes salty and unpleasant.
Sulfate (SO₄) accentuates hop bitterness — the defining characteristic of Burton-on-Trent's pale ales. High sulfate makes hops taste drier, crisper, more assertive.
Chloride (Cl) does the opposite: it enhances malt sweetness and fullness. The sulfate-to-chloride ratio is one of the most important levers in brewing water.
Bicarbonate (HCO₃) is alkalinity — it buffers mash pH upward. Dark malts need higher alkalinity to balance their acidity; pale beers need low alkalinity for a crisp finish.
The sulfate-to-chloride ratio
This single ratio tells you more about a water's brewing character than any individual ion:
- SO₄:Cl > 2:1 → hop-forward, dry, bitter (Burton, Edinburgh)
- SO₄:Cl ≈ 1:1 → balanced (Vienna, Dortmund)
- SO₄:Cl < 1:2 → malt-forward, full, sweet (Munich, Dublin)
Classic brewing waters
Pilsen is famous for its extraordinarily soft water — almost no minerals at all. This allows the delicate Saaz hop character and pale Moravian malt to shine without interference. Czech pilsner is a style born entirely from its water.
Burton-on-Trent sits at the opposite extreme, with sulfate levels above 700 mg/L from the local gypsum deposits. This aggressive mineral profile created the IPA style — the high sulfate snaps hop bitterness into sharp focus.
Munich has moderately hard water with high bicarbonate, perfect for the dark lagers that defined Bavarian brewing. The alkalinity balances the acidity of dark malts.
Getting started
The simplest entry point: pick a beer style you love, find its traditional water profile on this site, and mix the recipe we provide. Brew a batch with your usual recipe but our water, and taste the difference. Most brewers are surprised by how much water alone changes the result.