Tea
1979
Wedzicha, B.L.
Tea is drunk by more people than any other beverage in the world. More than 1 million tonnes are produced annually; tea is thus of major economic importance in world trade. Black, green, and instant tea are the main types and are made by processing the terminal bud and 2 adjacent leaves, called the flush. Black tea is the most commercially important. The freshly picked flush is allowed to wither so that it loses water and acquires a texture like a kid glove. Enzymatic action causes caffeine formation and starts the fermentation process. Fermentation is stopped, usually after a 3-hour period, by firing in a hot air stream, which also drops the moisture content to 3%. The most important stage in manufacturing black tea is the enzymatic oxidation of flavanol substrates. The resulting product is then graded for 5 factors; strength, color, briskness, aroma, and quality.
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