The slower growth of the tea leaves at high altitudes produce more flavorful tea. Tea gardens in the Darjeeling region of India or the Uva district of Sri Lanka, for example, are more than 6,000 feet high. Many of the world's tea producing regions also may have rainy seasons and dry seasons. While the rainy seasons are vital to the survival of the tea bush, the best teas are produced during the dry season. Many studies have indicated that black tea may possess some of the healthy properties associated with green tea, although the evidence is not as strong.
More research is needed to determines black tea's role in human health.
Manufacture Differences between green, black, and oolong teas occur during the processing of the tea leaves. Plucking All types are normally hand plucked. Pluckers take only the bud and two leaves, as only young leaves produce good quality tea. Machine plucked tea is usually inferior. Withering The next step in manufacturing is withering.