Water is 98–99% of every cup — bad water chemistry can flatten even great beans. Enter your water's TDS reading below to check it against the SCA Water Quality Handbook's target range.
This tool checks your source water before you brew. That one diagnoses your finished cup's TDS and extraction yield.
| Parameter | SCA Target | Acceptable Range | Why it matters |
|---|---|---|---|
| TDS (total dissolved solids) | 150 ppm | 75 – 250 ppm | Too low and extraction tastes flat/thin; too high and flavor is muted |
| Calcium hardness | ~68 mg/L | 17 – 85 mg/L | Calcium and magnesium bind to flavor compounds; too little under-extracts, too much scales machines |
| Total alkalinity | ~40 mg/L | 0 – 40 mg/L (as CaCO₃) | Buffers acidity — too high flattens brightness, tastes dull |
| pH | 7.0 | 6.5 – 7.5 | Extreme pH shifts acidity perception and corrodes equipment over time |
| Chlorine | 0 ppm | 0 ppm | Any detectable chlorine adds off-flavors — filter it out |
| Source | Typical TDS | Good for coffee? |
|---|---|---|
| Distilled / unremineralized RO | ~0–20 ppm | Too low as-is — remineralize with a mineral concentrate or blend with tap water first |
| Pitcher-filtered tap (Brita, PUR) | ~50–150 ppm | Usually good — reduces chlorine and some hardness while keeping minerals in range |
| Municipal tap water | ~50–400 ppm (varies widely by region) | Check your water utility's Consumer Confidence Report or test it — huge regional variance |
| Spring / bottled water | ~50–300 ppm (varies by brand) | Often good, but not guaranteed — mineral content varies brand to brand, check the label |
| Softened well water | Often 300+ ppm, high sodium | Usually too hard/high-sodium — cut with distilled or RO water |