Tap Water in CB23
Coton — Cambridge Water
Tap water in Coton, supplied by Cambridge Water, has the character of a chalk aquifer source, typical of southern and eastern England. It’s hard water, well above the national average, with a total hardness of 318 mg/L as CaCO₃. Bicarbonate is high at 364 mg/L: this water suits dark-roasted, milk-based coffee well, but will strip the acidity from lighter roasts and pour-over brewing.
Mineral composition
| mg/L | |||
|---|---|---|---|
| Calcium | 120 | ||
| Magnesium | 4 | ||
| Sodium | 13 | ||
| Sulfate | 26 | ||
| Chloride | 33 | ||
| Bicarbonate | ~364 | ||
| ~ Estimated from hardness and ion balance — not directly measured by the water company. | |||
Additional info
| Hardness | 318 as CaCO₃ |
| Alkalinity | 298.4 as CaCO₃ |
| pH | 7.5 |
| Conductivity | awaiting data |
| Source | Cambridge Water |
| Data year | 2024 |
What this means
Kettle & appliances
Limescale is a persistent issue. Kettles fur up quickly, and boilers, dishwashers, and washing machines all accumulate scale that reduces efficiency and shortens lifespan. Water treatment (a softener, inhibitor, or filter) is strongly recommended.
Espresso
Scale is a serious concern at this level: machines need regular descaling and filtration is strongly recommended. In the cup, the water has strong opinions. Light roasts lose their acidity and origin character almost entirely. But dark-roasted, milk-based espresso can work well here. London’s coffee culture developed around exactly this kind of water: strong, dark-roasted coffee served with milk, where the density and body that hard water produces become a virtue rather than a flaw.
Filter & pour-over
Hard water hits filter coffee harder than espresso because the brewing ratio gives it more influence. Lighter roasts will taste flat and indistinct; the buffering neutralises the acidity that carries fruit and floral notes. Darker roasts produce a drinkable but heavy cup. If you’re brewing pour-over with water this hard, the water is the first thing to address.
Drinking & cooking
Noticeably mineral-heavy on the palate. Soap and shampoo lather poorly. Tea may develop a film on the surface (that’s the calcium reacting with tannins). Cooking water may leave a chalky residue on pans.
Bicarbonate
Extremely high buffering that makes this water difficult to work with for any brewing or coffee application without significant dilution or acid treatment: mash pH will sit stubbornly high, extraction will be unbalanced, and espresso will taste flat and chalky with no discernible acidity.
Closest water profiles
Nearby areas
Data sourced from Cambridge Water (2024). Looking for a specific address? Look up your full postcode for the most accurate result.