Black, oolong, green and white tea all begin their lives as leaves on a single kind of plant: camellia sinensis. As you might guess, the difference is in the method of processing.
- White tea has undergone very little oxidation and has a very delicate flavour, more delicate than green tea. Immature tea leaves are picked while they are still covered with fuzz, then processed in low heat and dried. Because young buds and leaves are used for white tea, it is lower in caffeine than other varieties.
- Green tea consists of more mature leaves, but like white tea, it has undergone very little oxidation. After it has been withered, green tea is rolled and dried. Both green and white tea should be made using hot but not boiling water, as too-hot water will give the tea a bitter taste.
- Oolong, which means ‘black dragon’ in Chinese, is tea that has been partially oxidized, and can be thought of as somewhere between a green tea and a black tea. Brew this semi-oxidized tea in quite hot, but not boiling water.
- Black tea is the most oxidized form of camellia sinensis. It contains more caffeine than other forms of tea and is by far the most popular form of tea consumed in western countries. Black tea is produced with boiling water.
- Rooibos, or South African red tea, is harvested from aspalathus linearis, a member of the legume family. Technically it is a tisane and not a true tea, as it is not harvested from the camellia sinensis plant. Usually it is oxidized like black tea, although it can be produced like a green tea as well. Unlike black or green tea, it is completely caffeine-free. South Africans like their rooibos with milk and sugar, but the tea’s mild sweetness allows it to be served plain if desired.