Tea is one of the most popular drinks in the world, second only to water. There are over a thousand different varieties, the most common of which can be classified as white, green, oolong, and black. These classifications differ in their degree of oxidation, with black tea being the most oxidized. Green tea and white tea are not oxidized while oolong tea is partially oxidized. Oxidation, which occurs when the tea leaves are crushed and muddled together, produces a bright and tangy taste and higher caffeine content.
Scientists and tea drinkers are very interested in the health benefits of drinking tea. The purported benefits are numerous and include a reduced risk of cancer, increased brain health, lower weight and waist circumference, and increased muscle endurance. Teas that have experienced less oxidation are said to have the greatest health benefits.
Every culture has its own customs surrounding the consumption of tea. In Turkey, for example, very hot black tea is served in small, clear glasses accompanied by cubes of sugar. Customarily, a host offers this tea to guests as a sign of hospitality. In the United Kingdom tea is often taken with milk. In the United States, iced tea is particularly popular.