Water plays a big part in coffee, since most of coffee is actually water.
Having too much minerals in water could cause buildup of scale over time, which can damage espresso machines. However, distilled water won’t taste good when used in coffee because it is the minerals in the water that help extract the coffee.
Specialty Coffee Association Recommendations
The Target is the most desirable point in the Acceptable Range, although falling within the range is considered meeting the standard.
| Characteristic | Target | Acceptable Range |
|---|---|---|
| Odor (based on sensory olfactory determination) | Clean Fresh / Odor Free | |
| Chlorine | None | None |
| Calcium Hardness | 50-175 ppm CaCO_3 | 50-175 ppm CaCO3 |
| Alkalinity | 40 ppm | At or near 40-70 ppm CaCO_3 |
| PH | 7.0 | 6-8 |
See https://sca.coffee/research/coffee-standards
Water In Singapore
Singapore’s tap water is pretty soft: 21 mg/L total alkalinity (as CaCO3) and 61 mg/L total hardness (as CaCO3)