Building Water — Recipes and Remineralization
Once you understand that water is most of the cup, the logical next step is to stop hoping your tap is good and build your own to a known target. The recipe is always the same shape: start from near-zero water — distilled or reverse-osmosis (RO) — which is a blank slate with almost no TDS, then add back a controlled amount of minerals to hit a chosen GH and KH. This gives perfectly repeatable, competition-grade water anywhere in the world, independent of local supply.
#The Two Building Blocks ⚗️
Remineralization needs a source of hardness (calcium and/or magnesium) and, optionally, a source of alkalinity (bicarbonate) to buffer. The two most common DIY salts:
| Salt | Adds | Role |
|---|---|---|
| Epsom salt (magnesium sulfate, MgSO₄·7H₂O) | Magnesium → GH | Brightness, extraction, fruit |
| Baking soda (sodium bicarbonate, NaHCO₃) | Bicarbonate → KH | Buffering, balance, tames sharpness |
Some recipes add calcium (e.g. calcium chloride or food-grade calcium sulfate/gypsum) for body. The headline rule from the chemistry note holds: keep GH at or above KH so extracting minerals outweigh buffering ones.
#Two Approaches
DIY concentrate method: dissolve your salts into a small, strong "stock" solution, then dose a few millilitres of each concentrate into a litre of RO/distilled. Cheap, precise, infinitely tweakable. Commercial sachets: products like Third Wave Water, Lotus, Aquacode, or Perfect Coffee Water are pre-measured minerals you tip into a fixed volume — zero math, less control. Both start from the same blank RO/distilled base.
#A Worked Example 📐
Here is a classic, widely used Barista Hustle–style two-concentrate recipe targeting a balanced profile near the SCA ideal (~68 ppm GH, ~40 ppm KH). All weights are food-grade salts into distilled or RO water.
Step 1 — make two concentrates (per 1 litre distilled water each):
| Concentrate | Salt | Amount |
|---|---|---|
| Hardness | Epsom salt (MgSO₄·7H₂O) | 2.45 g |
| Buffer | Baking soda (NaHCO₃) | 1.68 g |
Step 2 — build a brewing litre:
| Into 1 L distilled/RO, add | Volume of concentrate |
|---|---|
| Hardness concentrate | 10 mL |
| Buffer concentrate | 10 mL |
Resulting water (approx): GH ≈ 68 ppm, KH ≈ 40 ppm, TDS ≈ 110–150 ppm — squarely in the target box.
Adjust to taste: more hardness concentrate for a brighter, more extractive water that flatters light roasts and juicy acidity; more buffer to soften a sharp, sour cup or to suit darker roasts. Always weigh salts on a precise scale and store concentrates refrigerated.
#Why Bother — and the Caveats ⚠️
Never brew with bare RO or distilled water — its near-zero mineral content extracts poorly and tastes hollow, and some sources note it can leach metals from equipment. It is a base, to be remineralized first.
The payoff is total control and perfect repeatability: the same water, every brew, so when you change grind or ratio you know the water held constant. For brewers who don't want to mix salts, the practical middle ground — good filters and the right bottled water — lives in Filtered, Bottled, and Tap Water.
#Continue Reading
- The SCA Water Standard — the target most recipes aim for
- Water Chemistry — Hardness and Alkalinity — the GH/KH logic behind the salts
- TDS and Mineral Content — verifying your build landed on target
- Filtered, Bottled, and Tap Water — the lower-effort alternatives
- Water for Coffee — back to the water hub