Tea leaves were originally consumed fresh, like a vegetable, added to soups and other dishes. It was considered to be medicinal, which made people overlook the bitter taste of raw tea leaves. Over time, changes in the way tea was picked, processed and prepared led to the elimination of the bitter flavor, making it a beverage to be enjoyed on it's own.
Green tea is made by heating the leaves over low heat, either in a pan, in an oven, or with steam. Low heat halts the oxidation while keeping the green color of the leaves. This process is known as sha qing - 'killing the green'. Shaping of the leaves can occur before, after, or during sha qing, and is a kind of signature to the type of tea. Finally, most green teas are lightly roasted as a finishing step, imparting a faint nutty flavor and aroma.
Japan is famous for it's green teas, including matcha - green tea powder now used as a flavoring in many desserts. Matcha is also whisked with hot water as a beverage used in the Japanese tea ceremony. Japanese green teas are steamed, causing the leaves to break down and shrivel up, and giving the leaves, and the brew, a bright green color. Hojicha is a heavily roasted green tea, with a rich auburn color .
Long Jing, or Dragon Well, is one of the most famous green teas. Produced in Hangzho, Dragon Well tea is heated in a large wok during shaqing. The pressing of the leaves against the pan gives them their characteristic flat shape. Other green teas, like Bi Luo Chun from Suzhou, use a circular motion, yielding twisted or balled shapes.