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 Ca 2+ and Mg 2+ . 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.