Tea types 茶

All tea is picked from one plant. The type depends on what happens to the leaf after picking.

Fresh green Longjing and aged pu-erh are leaves of the same species, the tea bush Camellia sinensis. Chinese tea scientists divide tea into six types (六大茶类) by processing. Chen Chuan, a professor at Anhui Agricultural College, proposed the system in 1979, and this whole site is organized around it.

Oxidation and fixation

Once picked, a leaf wilts, and its own enzymes oxidize the polyphenols. The leaf darkens, and the scent shifts from grass toward fruit and honey. The tea maker decides when to stop it. Heating the leaf briefly in a wok, with steam or with hot air, destroys the enzymes, and oxidation goes no further. This step is fixation, sha qing (杀青) in Chinese, literally "kill-green."

The earlier the fixation, the greener the tea. Green tea is fixed almost at once; oolong is shaken for hours first. Black tea is never fixed at all and oxidizes fully. In China it is called hong cha, "red tea," named for the color of the liquor.

The six types

Dark tea and fermentation

In five of the types, color and flavor come from the leaf's own enzymes. In dark tea, microorganisms do that work. Makers moisten the leaf and heap it into a pile (wo dui, 渥堆). The pile heats up, and fungi and bacteria transform the leaf over anything from a few hours to two months, depending on the tea. That is why this site keeps the word "fermentation" for dark tea and says "oxidation" for the rest. Chinese texts use one word for both processes, 发酵.

Type and brewing

The type tells you the water temperature. Green and yellow teas take water at 75–85 °C, while oolong and dark teas take it at a full boil. Brewing in short infusions in a small vessel is the gongfu cha method. Gaiwans, teapots and fair cups have their own Teaware section.