Brewing water
London water
Moderately hard with substantial bicarbonate and low sulphate — suited to porter and brown beer rather than pale ale.
London, United Kingdom
Read this as a reconstruction. Figures are the widely-reproduced historical analysis, stored as a range because the underlying supply varied by well, by season and over time. Treat them as an indication of relative character, not as a specification to dose water against. London draws water from more than one source, and figures vary considerably across the city.
Mineral content
| Ion | mg/l | What it does |
|---|---|---|
| Calcium (Ca²⁺) | 40–90 ppm | Lowers mash pH, supports enzyme and protein behaviour, aids yeast flocculation and clarity. Close to flavour-neutral itself. |
| Magnesium (Mg²⁺) | 15–45 ppm | A yeast nutrient in small amounts. Above roughly 30 mg/l it begins to read as sour or metallic. |
| Sodium (Na⁺) | 60–110 ppm | Rounds and accentuates sweetness at moderate levels. With high sulphate it turns harsh rather than full. |
| Chloride (Cl⁻) | 25–50 ppm | Tends to accentuate malt fullness, body and roundness. A tendency in perception, not an additive sweetness. |
| Sulphate (SO₄²⁻) | 20–50 ppm | Tends to accentuate hop bitterness and drive a drier finish. At high levels it reads as harsh and minerally rather than simply more bitter. |
| Bicarbonate (HCO₃⁻) | 80–160 ppm | The alkalinity that resists mash acidification. High bicarbonate needs dark, acidic malt to balance it — which is why alkaline-water cities brewed dark beer. |
Overall hardness: moderately hard. Balance: balanced (chloride:sulphate roughly 1.07:1). The ratio is a shorthand the trade finds useful for describing whether a water pushes a beer toward crispness or fullness. It is not a formula, and two waters with the same ratio at very different total concentrations do not behave alike.
Historical context
Comparatively low sulphate and useful alkalinity favour malt-forward, darker beer. Set against Burton, the contrast is the single clearest illustration in brewing of water shaping regional style.
Styles associated with this water
Association, not causation. Brewers selected recipes that worked with the water available to them; the water did not design the beer.
Other water profiles
- Balanced reference profile — moderately hard, balanced.
- Burton-on-Trent water — very hard, strongly sulphate.
- Dortmund water — hard, sulphate leaning.
- Dublin water — hard, sulphate leaning.
- Edinburgh water — hard, sulphate leaning.
- Munich water — moderately hard, balanced.
- Pilsen water — very soft, balanced.
- Vienna water — hard, sulphate leaning.
Last reviewed 2026-08-15.