by joelbct » Apr 16th, '08, 17:15
U sure about that Wes?
I thought neither White nor Green tea were oxidized, and the difference was that White tea is not withered, just air dried or fired then dried, whereas Green tea is withered then steamed or fired.
Here is some info from a brief paper I put together last year:
Processing/ Types
The harvested leaves are processed in two ways, the first being the “CTC method” standing for “crush, tear, curl.” This is an entirely mechanized process used for lower quality tea.
The second is called the orthodox method, used for higher quality leaves. This process differs depending on the type of tea, but is generally comprised of withering, rolling, oxidation, and firing.
First, the leaves are spread out in open air, until they wither and become limp. Next, they are rolled and tumbled, or “bruised,” either by machine or by hand, releasing a variety of enzymes. The next step, oxidation, is a reaction in which leaves turn progressively darker when the chlorophyll breaks down, releasing tannins. This process is commonly referred to as “fermentation,” which is a misnomer because no true microbial fermentation takes place. Instead, the process is entirely chemical.
Finally, the leaves are heated, or “fired,” to end the oxidation process and dehydrate the leaves so they can be stored and shipped.
This process produces the Black tea varieties, which are fully oxidized.
Green tea is minimally oxidized, instead simply withered; then steamed (the Japanese method) or fired in hot pans (the Chinese method).
White tea is the least processed form, generally not oxidized at all, only picked and air dried, or fired and then dried.