ORAT tool · brewing water
Coffee Water Calculator
A practical calculator for building repeatable brewing water from low-mineral water and simple mineral additions.
Beta
Recipe helper
Record your own result
Purpose
Repeatable water
The calculator helps turn a water recipe into measured additions, so a brew can be repeated instead of guessed.
Best starting point
Low-mineral base water
It is most useful with RO, distilled, or very low-TDS water where the mineral additions are doing the main work.
Reality check
Taste still decides
Numbers help with consistency, but they do not tell you whether the coffee is better. Brew, taste, and adjust calmly.
A few cautions
- Use accurate scales and food-safe mineral sources.
- Label concentrate bottles clearly and keep them away from children or pets.
- Do not treat the calculator as medical, dietary, or water-safety advice.