Tea comes from the top two leaves and bud of an evergreen shrub called Camellia sinensis and is available in thousands of different forms. In this regard it is similar to wine, with the region, climate, soil, and processing determining its characteristics.
It is split into four main varieties: black, green, oolong, and white.
Black tea: the leaf is withered and water is evaporated, allowing the leaf to absorb more oxygen from the air (called oxidation). The dark brown and black leaf comes from the full oxidation and it yields a hearty and more pronounced flavor as well as higher caffeine content than other teas.
Another variety, Puerh, is sometimes classified as a fifth type of tea, but it is simply an aged black tea from China. It was actually illegal to import Puerh to the US before 1995 and it is still a closely guarded state secret in China. It is deep and rich in flavor.
Green tea: the leaf is only slightly withered and undergoes a very quick oxidation process that is stopped with a rapid heating called “firing.” This allows for a more delicate tea with subtle flavors and undertones and a pale green or golden color.
Oolong tea: After withering, the leaf undergoes partial oxidation that gives the tea a flavor and caffeine content somewhere in between black and green teas.
White tea: Taken only from the youngest shoot of the plant, white tea is handled in the most delicate of all processes. It is not oxidized or rolled, but becomes withered and dried by steaming. The minimal processing leaves more antioxidants intact than in green tea. (It also has very low caffeine.)
What about herbal teas?
Herbal tea is a misnomer, according to purists, who say that tea can only come from the Camellia sinensis plant. Instead, such mixes should be referred to as infusions or tisanes (from the French word for infusions). Packaged and brewed just like tea, they come from grasses, barks, fruits, flowers and other botanicals. They do not contain caffeine. Some of the more common herbal infusions are Chamomile (aiding relaxation and sleep), Peppermint (aids digestion), Ginger (for upset stomach), and Ginseng (for energy).
What about “red” teas?
Red tea also isn’t technically a “tea” but rather the dried needles of the African rooibos herb. It is caffeine-free and rich in antioxidants, and makes a mellow and rich “red” colored brew.
What about “chai” tea?
Chai simply means spiced tea (and is the word for tea in Hindi and other Asian languages). Most often served with steamed milk (or soy milk) and has quickly become one of the fastest growing varieties of teas.