TDS (water)

Total Dissolved Solids — the total mineral content of water, measured in parts per million (ppm) with a TDS meter. Different from coffee TDS (which measures dissolved coffee in the beverage).

Why it matters — Ideal brewing water sits at 75–150 ppm TDS. Above 300 ppm, the water tastes chalky and scales fast. Below 50 ppm, the water extracts flat and muted coffee.

Good to know

• A handheld TDS meter costs very little and gives instant feedback on your filtration.
• TDS doesn't tell you which minerals are in the water — two waters with the same TDS can taste very different depending on the mineral mix.

Related: Water Filtration