When producing black, pu'erh and oolong teas there is an additional purpose of processing: to encourage oxidization, which further develops flavour and aroma compounds.
The domestication of tea and the development of its processing method likely began in the area around what is now Southwest China, Indo-Burma, and Tibet.
[3] For consumption, dried tea leaves were either decocted with water and other herbs, or ground into a powder to be taken straight, or suspended in a liquid in the manner of matcha.
[3] The preference of producing tea in brick form possibly stems from the fact that it can be more easily transported and stored.
By the end of the Tang dynasty (618–907 CE) green, yellow, and post-fermented tea was commonly used in China and moved from purely being used in herbology to becoming a beverage drunk for pleasure.
[8] When there was insufficient sun and temperatures were low, the withered leaves would be processed indoors in warmed rooms and allowed to fully oxidize, then smoked dry over pine fires thus producing lapsang souchong.
[8] According to oral traditions of the region, the discovery of Lapsang Souchong processing was due to military troops passing through a Wuyishan tea factory during the last years of the Ming dynasty, causing delays to tea leaf processing thus resulting in a completely oxidized leaf that the producer salvaged by drying over a fire built from pine branches.
[9] By the Qing dynasty, both Lapsang Souchong and Gongfu black tea were well recognized in China and noted in "Records on Yiwu mountain" (武夷山志) by the scholar Dong Tiangong (董天工).