Tuesday October 21, 2008 | 2 comments
Eighth in a series on teas from China.
Oolong (semi-fermented) and black (fermented) teas are a fairly recent development in China, if anything there may be called recent. What distinguishes teas of this type from green or white (unfermented) teas is “fermentation,” though this is the wrong word for what should really be called oxidation. (“Tannin” is another term inherited from from the previous age and its faulty understanding of chemistry. Tea’s polyphenols bear no relation to tannic acids.) Fresh leaf tea is allowed to wither until enough moisture evaporates for the leaf to become flaccid. To make green tea, withered leaf is simply fired – traditionally in a hot wok – while a tea maker continuously rolls the leaf to and fro. This rolling gives the leaf its shape as it dries, while the heat “kills” the leaf and arrests further chemical change. To make black of oolong tea, withered leaf is rolled without firing. This turns it into a mass of bruised and sticky leaves whose juices are now exposed to the air. When this green mass is spread out for the exposed juice to oxidize, it begins turning brown, as would a freshly sliced apple. If allowed to oxidize completely before firing, the leaf will make black or fully fermented tea. If the leaf is partially but not completely oxidized, the product is called semi-fermented or oolong tea. Obviously, the way to obtain the result desired is to control and stop the oxidation process at just the right moment.
The Chinese have brought this process to perfection in Fujiian and Guangdong and directly across the straits in Taiwan. Here the classic oolongs are made by throwing the leaf into very hot woks to steam and
crackle while it is stirred very fast to keep it from scorching or sticking. Soon the leaf is taken out to be rolled some more, usually in cloth bags which are trod upon and twisted tighter and tighter. The leaf is then allowed to oxidize further before before being thrown back into a wok for further firing. The color and fragrance of the leaf change as it oxidizes, and these progressive changes determine the intervals between firings; finally, it is rendered crisp and dry in baskets over low charcoal fires. The Chinese call fire “the teacher of tea” and except that electric power has replaced charcoal, this procedure of repeated oxidizing and firing is unchanged in the production of any first-rate oolong tea. The best of these teas is still largely manufactured by hand (and foot), which means every cup you enjoy represents someones’s skilled hands, someone’s aching knees and hips, someone’s pride in accomplishment. No wonder the taste is so deeply satisfying.
Next week: Bohea (Wuyi), a special oolong
There will be three posts on oolong: Bohea (October 28); Ti Kuan Yin (November 4); Shuixian and Fenghuang Dancong (November 11).
MAIN
Image 1

Thanks James! This is the first article ever where oolong oxydation process is clearly and thouroughly explained. But, the last step of oolong fabrcation is missing from this summary: the roasting.
Indeed, for almost all oolong teas, after oxydation and last firing, the dry leaves are roasted. This allows to gain the caramel or honey taste so caracteristic for oolongs; It helps also to develop fruit, heady flower, wood and confection/patisserie tastes. This raosting process can be very light as for high mountain taiwanese oolongs or some Anxi Tie Guan Yin, middle for Dong Ding or modern Wuyi Yancha or very high for traditionnal Wuyi Yancha as Da Hong Pao or Rou Guei. The only classical oolongs where there is no roasting process are Wen Shan Baozhong and some very fresh high mountain oolongs. This phase requires all the skills and secrets of generations of tea farmers…
As you said, no wonder the taste is so deeply satisfying.
the process explained is really in a very neat form. thank you. it will help people understand things more simply.