Q: What is the difference between black and green tea?-- Josie
Tea, whether green or black, is made from leaves of the plant Camellia Sinensis. Beverages made by infusing the leaves or parts of other plants, such as rose hips, chamomile or mint, are technically tisanes.
In making black teas, the leaves of the tea plant are left to wilt, for a period of minutes to hours. Withering is usually done on racks or screens. Next, the leaves are pressed to break down the cell structure, allowing the release of natural enzymes. These enzymes darken the tea leaves, much as enzymes turn the flesh of a freshly sliced apple brown, and at the same time cause changes in flavor, color and body. When the enzyme action has reached the desired point, the leaves are heated to inactivate the enzymes, by allowing heated air to pass through or around the leaves.
In green tea, the enzymes are not allowed to react with the leaves. They are inactivated early by pan-firing the tea, or air drying it. In Japan, the leaves are steamed after picking, which destroys the enzyme, while retaining the fresh, grassy flavor of the fresh leaves.
In both cases, the final step is to dry the tea completely to prevent spoilage.
Oolong tea is a mid-way process, where the enzyme actions are limited. The process is slightly different from that described above.
My favorite, of all teas, is Lapsang Souchong, which is a black tea that is dried over a smoky pine fire adding a distinctive aroma. My wife, however, refers to it as "smelly moccasin tea" because of it smoky smell!