The earliest Dark (post-fermented) Tea appeared in Han Dynasty with 2,000 years in history in Hunan province. Post-fermented means tea's processing includes both fermentation and then prolonged storage, or 'aging'. The longer a dark tea is aged; the better the taste will be. It can also taste earthy because of the aging process. Currently, dark tea is produced mainly at a city called Pu-erh in the Yunnan district in the southwestern part of China.
Dark tea processing involves the application of heat and moisture, as well as the inoculation of the tealeaves with beneficial bacteria. It takes about a year for harvested tealeaves to become 'ripened' or 'finished' pu-erh. Some 'ripened' pu-erhs are also aged for a flavor more similar to traditionally produced pu-erh.
Caffeine compared with coffee
Possible Health Benefits
Prevention of cardiovascular disease
Improve carbohydrate metabolism
lower blood sugar
Reduce tobacco and alcohol poisoning