Tap water in most of England is too hard for coffee. The good news is that the right bottled water costs about 30p a litre, and most big supermarkets sell one.
The number that matters most is alkalinity: how much the water resists acid. Coffee’s flavour is mostly acids. Too much alkalinity neutralises them, and the cup goes flat and heavy. Too little, and it tastes sharp and thin. The Specialty Coffee Association (SCA) water standard puts alkalinity at 40–70 mg/L (measured as calcium carbonate), and the waters below are judged against that.
If you’re not sure, buy this
Tesco British Natural Mineral Water in the 5 L bottle (about £1.50, Tesco only), or Aqua Pura (Tesco, Sainsbury’s, Asda, Morrisons). Both come from the Eden Valley in Cumbria, and both sit almost exactly where the SCA standard says they should: total hardness around 60–75 mg/L, alkalinity around 40 mg/L. At Waitrose, Waitrose Essential Still has a near-identical mineral profile. Check the pack: Tesco’s 2 L bottle is a different, harder water from another source (total hardness 137 mg/L, alkalinity 115 mg/L) and does not suit coffee.
This isn’t a new discovery. Tesco’s previous water from the same valley, Ashbeck, was the UK coffee forums’ default for years. Its replacement does the same job, in the 5 L bottle.
UK bottled waters for coffee, compared
| Bottled water | Where to buy | Typical price¹ | Total hardness (mg/L) | Alkalinity (mg/L) | Filter | Espresso |
|---|---|---|---|---|---|---|
| Tesco British Natural Mineral Water, 5 L | Tesco | £1.50 / 5 L | 63 | 38 | Good | Good |
| Waitrose Essential Still | Waitrose | £0.25–0.35 | 63 | 38 | Good | Good |
| Aqua Pura | Tesco, Sainsbury’s, Asda, Morrisons | £0.25–0.45 | 76 | 45 | Good | Good |
| Volvic | All major supermarkets | £0.50–0.80 | 62 | 58 | Good | Good |
| Sainsbury’s Caledonian | Sainsbury’s | £0.20–0.30 | 63 | 26 | Bright, can taste sharp | Bright, can taste sharp |
| Deeside | Tesco, Waitrose | £0.80–1.50 | 22 | 22 | Too soft: thin and sour | Too soft: thin and sour |
| Highland Spring | All major supermarkets | £0.42–0.67 | 143 | 123 | Flat | Flat, builds scale |
| Tesco British Natural Mineral Water, 2 L | Tesco | £0.80 | 137 | 115 | Flat | Flat, builds scale |
| Asda Still | Asda | £0.78 | 158 | 136 | Flat | Flat, builds scale |
| Buxton | All major supermarkets | £0.33–0.50 | 216 | 203 | Flat | Avoid: scales fast |
| Evian | All major supermarkets | £0.67–1.00 | 307 | 295 | Flat | Avoid: scales fast |
¹ Per bottle, as last checked (most in March 2026). Bottle sizes vary, so compare per litre on the shelf. Labels round their figures, and brands change sources: we update this table when we find out.
Espresso and filter want slightly different things
Filter coffee is forgiving about hardness. Its problem is alkalinity: above about 70 mg/L, the cup loses its brightness.
Espresso adds a second problem: scale. Hard water leaves calcium deposits in the boiler, and that costs you a descaling job or, eventually, a repair. Keep total hardness under about 100 mg/L for an espresso machine and you’ll rarely need to think about it.
What about tap water or a filter?
Tap water in London and most of the South East and East of England has total hardness above 200 mg/L, three times what you want. A jug filter like Brita takes out some hardness and bicarbonate, but in hard-water areas that’s usually not enough for coffee. In soft-water parts of Scotland, Wales and the North West, tap water may already be fine.
Common questions
What's the best bottled water for coffee in the UK?
Tesco British Natural Mineral Water (5 L bottle), Aqua Pura or Waitrose Essential Still. All three are low in alkalinity and moderately soft, which is what coffee needs.
Is Volvic or Evian better for coffee?
Volvic, by a long way. Evian’s alkalinity is about five times Volvic’s, which flattens the cup and scales espresso machines.
Should I use tap or filtered water for coffee?
It depends on where you live. In hard-water areas, a jug filter helps but doesn’t get you to the right range. Check your postcode before buying anything.
Is distilled water good for coffee?
No. With no minerals at all, coffee extracts badly and tastes hollow. Distilled water is useful only as a base for mixing minerals back in.