Black tea is a type of tea that is more oxidized than oolong, green and white teas.Black tea is generally stronger in flavor than the less oxidized teas. Green tea usually loses its flavor within a year, While black tea retains its flavour for several years.
In Chinese languages and the languages of neighboring countries, black tea is known as "red tea", a description of the color of the liquid; the Western term "black tea" refers to the color of the oxidized leaves.
CTC Black Tea