The Chinese are thought to have once produced 8,000 different types of teas - all from a single plant species. Even today, all true “tea” comes from the same plant, the famed Camellia sinensis. The notion that the same leaf can produce such strikingly different liquors is bewildering, especially when one recalls the fresh, vegetal taste of a Japanese green sencha as compared to a hearty Assam or Ceylon.
Just as with wine grapes, there are many factors that determine the characteristics of the final product. Black teas produced in China differ in flavor from those produced in India, and those of Sri Lanka (formerly Ceylon) have yet another character. The unique character of a tea – the quality, taste and aroma – is governed by climatic and soil conditions, as well as altitude, time of picking, and manufacturing expertise. Yet the basic manufacturing process is what determines whether the tea will be “green” or “black.”
The manufacturing process is the series of procedures that determines the shape and flavor of a batch of tea leaves. The process includes harvesting, withering, rolling or crushing, and, in some cases, fermentation. At one time, all processing of tea was done by hand in a carefully executed series of stages first developed by the Chinese. Today, far fewer teas are handmade; instead, machines carry out the majority of the manufacturing processes.Withering
The process of allowing the fresh leaves to dry. Some producers have special withering rooms, whereas others wither their tea in the open air.Rolling
Twists and breaks the leaves to release the natural juices. This action activates enzymes that help to initiate fermentation. Rolling also gives the leaves a curled appearance.Crushing
(Or cutting) is an alternative to rolling. It serves the same purpose, but finely chops the leaves instead of breaking them into large pieces. Cutting enables tea to brew quickly and produce a dark infusion.Fermentation
The process of oxidizing green tea leaves to make black and oolong teas. The green leaves are spread out and exposed to the air for three to four hours. During this chemical process, the leaves turn red-brown – this gives fermented tea its dark appearance.
All fermented teas undergo a similar enzyme-oxygen reaction; however, the duration and temperature at which the reaction occurs are critical to the final product. Fully oxidized (“fermented”) leaves become black tea, whereas partially oxidized (“semi-fermented”) leaves produce Pouchong and the various Oolong styles of tea.Handmade
There is a range of machine types used in tea production, some adhering more closely than others to traditional manufacturing methods. The term orthodox is used by the tea industry to designate methods that adhere to traditional production guidelines. Orthodox processing calls for a wither of 18-24 hours, two to six rollings of one half-hour each, and a fermentation of 3-4 hours. There are also specifications for firing and drying.
With emphasis shifting to production efficiencies, the majority of tea production today is unorthodox. One of the most popular unorthodox processing methods is C.T.C (crush, tear, curl or cut, tear, curl). C.T.C machines manufacture fine leaf particles, whereas traditional rolling or crushing produces whole leaf or larger leaf teas. C.T.C. methods are generally thought to turn out inferior grade teas, although this is changing as the technology improves.The Manufacturing Processes
Producing tea takes about 36 hours or less for most varieties, but the steps vary from one tea type to the next. To produce white tea, fresh tea leaves are picked, and then withered for several hours. Next they are dried until they have lost 93-95% of their moisture content. By contrast, black and green tea production involves withering and drying, but also requires additional steps, including rolling or crushing (this process releases oils and enzymes, inducing chemical changes) and fermentation.