Skip to content

How do I make coffee recipe water?

Start with distilled or RO water and add a measured mineral concentrate. It is the only way to control it exactly.

Recipe water means building your brewing water from scratch rather than treating tap water.

Why

Reproducibility. Tap water varies by season, by supply and by region. Built water is identical every time.

Precision. You can target the exact mineral profile you want, rather than whatever the filter happened to remove.

The method

Start with a blank — distilled or reverse osmosis water, which has essentially no dissolved minerals.

Add a measured mineral dose. Either a commercial sachet designed for a fixed volume, or a home-made concentrate.

The targets

Total hardness — 50 to 175 ppm as CaCO₃, ideally around 70 to 100. Alkalinity — around 40 ppm, and below 70. Magnesium favoured over calcium, since it extracts the flavours people want and scales less.

Commercial sachets

Third Wave Water, Lotus, Aquacode and others. Add one sachet to a fixed volume of distilled water.

Simple, consistent, and expensive per litre.

Home-made concentrates

Epsom salt (magnesium sulphate) and baking soda (sodium bicarbonate) dissolved in distilled water as separate stock solutions, then dosed by volume.

Very cheap, and it requires a scale accurate to 0.01 g and some care.

Is it worth it

For filter, black, with good beans — yes. The difference is larger than most equipment upgrades.

For milk drinks — much less.

The warning

Never brew with distilled water alone. It extracts almost nothing and tastes hollow.

Last reviewed 8 August 2026