Oxidation levels in true tea from Camellia sinensis, determine what category of tea you end up with. After harvest, tea leaves go to a factory for tea manufacturing. During processing, tea leaves are withered and manipulated into the type of tea ordered—black, oolong, etc.

The type of tea determines how much oxidation is allowed in that particular batch. A process called “kill green” applies heat to the green tea to stop oxidation, while black tea oxidizes to nearly or at 100%.

Some people confuse the terms oxidation and fermentation. All teas fall somewhere on the oxidation continuum scale. However, the only fermented tea is puerh.