Roasted barley tea is a caffeine-free, roasted-grain-based infusion made from barley, which is popular in Japanese, Chinese, and Korean cuisine. It is also used as a caffeine-free coffee substitute in American cuisine. Barley water is a popular traditional soft drink in Britain.
Roasted barley tea is called mugicha (麦茶?) in Japanese, dàmàichá (大麦茶) or màichá (麦茶 or 麥茶) in Mandarin Chinese, and boricha (보리차) in Korean. While the tea is generally regarded as a cooling beverage in Japan, it is served year-round, mild in summer and cool in winter, in Korea. Originally, roasted barley seeds were stewed in hot water (this is still the method generally used in Korea), but tea bags containing ground barley became more popular during the early 1980s; this is now the norm in Japan. It can be found from many different distributors in vending machines all over Japan.
In Korea, roasted unhulled barley is used to prepare the tea. Often the barley is combined with oksusu cha (roasted corn), as the corn’s sweetness offsets the slightly bitter flavor of the barley. A similar drink, made from roasted brown rice, is called hyeonmi cha or genmaicha (with green teaadded).
Roasted barley tea was found to inhibit bacterial colonization and adhesion, specifically with respect to the major cause of tooth decay also implicated in cardiovascular diseases, Streptococcus mutans biofilms. It also lowers blood viscosity, proportional to the level of alkylpyrazine in the tea