Effects of different types of water on the sensory and physicochemical properties of cold - brewed green tea.

Brewing water significantly influences tea infusion quality, yet its role in cold-brewed green tea remains underexplored. This study investigated the effects of four water types-direct drinking water (DDW), pure water (PW), mineral water (MW), and distilled water (DW)-on the sensory and physicochemical properties of cold-brewed green tea. Mineral dissolution varied by water type, with Se, Ca, Hg, Pb, and As being key differentiating elements. Brewing with MW resulted in a flat taste and dark color attributable to low flavor components and interactions involving Ca2+ and Mg2+. PW and DW led to higher catechin and caffeine levels, which intensified astringency and bitterness. In contrast, DDW enhanced sweetness, reduced bitterness, possessed a vibrant infusion color, and achieved the highest Se content. With its moderate Ca/Mg levels and neutral pH, DDW is optimal choice for cold brewing, offering practical guidance for both consumers and the tea industry.