Black tea is a variety of tea that is more oxidized than the oolong, green, and white varieties. All four varieties are made from leaves of Camellia Sinensis. Black tea is generally stronger in flavor and contains more caffeine than the less oxidized teas.

In China, black tea is also known as “red tea”, a description of the colour of the liquid; the term black tea refers to the colour of the oxidized leaves. While green tea usually starts to lose its flavour within a year, black tea retains its flavour for several years.

A 2001 Boston University study has concluded that short and long-term black tea consumption reverses endothelial vasomotor dysfunction in patients with coronary artery disease. This finding may partly explain the association be-tween tea intake and decreased cardiovascular disease events.