Water for Brewing

Introduction

Lu Yu wrote in the Cha Jing (760 CE) that the quality of water determines the quality of tea. Thirteen centuries later, modern chemistry has confirmed his wisdom. {{glossary:water-quality}} influences extraction efficiency, flavor expression, color, and aroma — often more dramatically than switching between two mid-range teas.

Mineral Content (TDS)

Total dissolved solids (TDS) is the sum of all minerals in water, measured in parts per million (ppm). Under 50 ppm (distilled, RO): Too pure. Lacks the trace minerals that carry and support flavor. Tea tastes flat and lifeless. 50-150 ppm: The ideal range. Enough mineral content for body and flavor transport without suppressing extraction. 150-250 ppm: Acceptable but beginning to suppress brightness. Above 250 ppm: Hard water that actively interferes with tea. Calcium and magnesium bind polyphenols, dulling flavor and creating a surface film.

pH

Ideal brewing water is slightly acidic to neutral: pH 6.5-7.5. Acidic water (below 6.0) can make tea taste sharp and thin. Alkaline water (above 7.5) flattens flavor and darkens the liquor color. Most municipal water falls within an acceptable pH range.

Contaminants

Chlorine: Common in municipal water. Detectable at low concentrations and particularly noticeable in delicate green and white teas. Removed by carbon filtration or by simply leaving water uncovered for 30 minutes (chlorine evaporates). Chloramine: A more stable disinfectant used by some water systems. Requires catalytic carbon filters — standard carbon is insufficient. Iron and copper: Metallic off-flavors and interference with polyphenol chemistry.

Practical Solutions

For most people, a carbon pitcher filter (Brita, PUR) or under-sink carbon filter produces excellent brewing water at minimal cost. If your water is exceptionally hard, consider Third Wave Water or similar mineral packets added to distilled water — these provide a precise mineral profile optimized for tea and coffee extraction.