Types of Tea
All teas except herbal teas come from the Camellia Sinensis species of plants. Herbal teas come from herbs which are not technically tea. There are three main varities of the camellia sinensis tea plant:
India or Assam tea - this a large-leafed tea that grows well in lower altitudes
China tea - this a small-leafed tea that grows well in higher altitudes
Hyrbid tea - this is a mixture of the India and China tea
Four Main Types of Tea
There are four main types of teas derived from the three varieties of teas species; Black, Green, Oolong, and White.
Black Teas are the most popular teas in the world. They contain the most caffeine and the least amount of antioxidants. Black tea is processed using a method that allows the tea leaves to become fully oxidized. After harvesting, green tea leaves are allowed to wither allowing all the water to evaporate. After the leaves wither, they are rolled in order to crack the surface of the tea leaves allowing oxygen to penetrate and react with enzymes resulting in oxidation. The tea leaves are allowed to fully oxidize turning the once green leaves into a dark color. After this process, the black tea leaves are sorted, graded, and packaged.
Green Teas are non-oxidized. They are low in caffeine and high in antioxidants. Like black tea, the tea leaves are allowed to wither after they are harvested. This allows most of the water to evaporate. However, unlike black tea, the tea leaves are not allowed to become oxidized. To prevent oxidization, the leaves are steamed or pan fried. After this, they are rolled into various shapes and allowed to dry again. This results in dry green-looking leaves. They are then sorted, graded, and packaged. Green teas have more a grassy taste.
Oolong Teas are partially oxidized teas and are considered to be somewhere between black and green teas. They are considered the most difficult to process because they have to be bruised rather than broken like black teas in order to allow for partial oxidation. After plucking, the tea leaves are allowed to wither to allow for water evaporation. The leaves are then tossed in baskets in order to bruise the edges of the leaves and allow for partial oxidation. Afterwards, they are steamed to stop the oxidation process. As you can expect some of the leaves are more oxidized than others resulting in Oolong teas that are more like black teas or green teas depending on the level of the oxidation.
White Teas are the least processed teas. Of the four types of teas, white teas contain the least caffeine and the highest antioxidants. Whites teas are tightly rolled from plucked buds and are not oxidized at all. They are allowed to dry for a short period of time and then fired or steamed to prevent oxidation. Because they are processed from buds, white teas have silverish appearance from new growth .