Water for tea and coffee
Not a contaminant — an extraction problem. And the answer is not the purest water you can make.
Some filter jugs handle thisBrewing is chemistry, and mineral content is a reagent in it. Water with no dissolved minerals at all extracts coffee badly, producing a thin, sour cup, which is why the specialty coffee world publishes target mineral profiles rather than telling everyone to use distilled water. Tea is more forgiving but responds strongly to hardness, which is what puts the film on the surface of a cup of black tea. This is the one page on the site where the answer to 'which jug filters most' is 'not that one'.
How you know you have it
- An oily film on the surface of black tea
- Espresso that tastes flat or hollow despite a good grinder and fresh beans
- A kettle or coffee machine scaling up within weeks
What works
For tea, a hardness-focused cartridge — Brita's Limescale Expert grade or a magnesium mineralising cartridge such as BWT's. For coffee, BWT's magnesium approach has a real following, because magnesium specifically improves extraction.
What does not
ZeroWater, for coffee. It works exactly as advertised and the result is water with nothing in it to extract with. For a kettle it is fine; for espresso it is the wrong tool, and this surprises people.
Cartridges worth considering for tea & coffee
Not a contaminant, so no cartridge is certified 'for coffee'. These are the ones whose approach — hardness reduction, or magnesium mineralisation — matches what brewing actually responds to.
Questions
Does a filter jug remove tea & coffee?
Some do, and most do not. For tea, a hardness-focused cartridge — Brita's Limescale Expert grade or a magnesium mineralising cartridge such as BWT's. For coffee, BWT's magnesium approach has a real following, because magnesium specifically improves extraction.
What does not work: ZeroWater, for coffee. It works exactly as advertised and the result is water with nothing in it to extract with. For a kettle it is fine; for espresso it is the wrong tool, and this surprises people.