Phenolic content in tea green tea. Catechins constitute about 25% of the dry mass of a fresh tea leaf, although total catechin content varies widely depending on species, clonal variation, growing location, season, light variation, and altitude. They are present in nearly all teas made from "Camellia sinensis", including white tea, green tea, black tea and oolong tea. Of all the catechins in tea, EGCG is the main subject of scientific study with regard to its potential health effects. 4-Hydroxybenzoic acid, 3,4-dihydroxybenzoic acid (protocatechuic acid), 3-methoxy-4-hydroxy-hippuric acid and 3-methoxy-4-hydroxybenzoic acid (vanillic acid) are the main catechins metabolites found in humans after consumption of green
Korean tea as ancestral rites often involved offerings of tea to the ancestors. Wedding ceremonies also included tea offerings. The practice of packing tea into small cakes, which lost popularity in China during the 14th century, continued in Korea until the 19th century. In 1895, King Gojong of the Korean Empire used coffee for the first time. In 1896, grocery stores began to have tea rooms as annexes, and the first modern tea house was established in 1924. Although tea from the "Camellia sinensis" plant is not as popular as coffee in South Korea - with the annual South Korean tea consumption