Green teas originate from China and are minimally oxidized tea leaves. Oxidation is the chemical reaction which starts as soon as the leaves are picked, and is also referred to as fermentation. Shortly after the leaves are picked, they are either pan-fried, steamed, baked, or sun dried in order to halt the oxidation process. This classifies them as a green tea. The region of cultivation, and the method of processing contribute to define the character of specific green teas, while the soil type, elevation, and agricultural practices of the tea garden contribute to the flavor of the tea. It is possible to tell from a sip of tea its exact origin and method of cultivation.