Water for Espresso: Why It Matters and What to Use
Water is 90–98% of your espresso. Ignore it, and even great beans and a perfect grind can produce flat, sour, or scaled-up shots. The ideal water for espresso is neither too soft nor too hard — it has enough minerals to extract flavor, but not so many that it scales your boiler or makes coffee taste chalky. Why Water Quality Affects Espresso Taste Water extracts flavor compounds from coffee grounds through its mineral content, specifically the dissolved calcium and magnesium ions. These minerals carry bitter and sweet flavor compounds out of the grounds and into your cup. ...