Puerh History - Pu-erh.Net

„The most classical Puerh Tea is the Bingcha, recorded in Yong-Zheng 13th year in Qing Dynasty (1735). Each tea cake weighs 7 Liang (357 grams). Seven cakes make 1 Tong (wrapped in leaves), weighing 49 Liang. It was sold in nice places and also was exported abroad. It was re-named as "Yunnan Qizi bingcha - Yunnan seven cake tea" during the Cutural revolution.“

„Yunnan Tea Company standardized the trade number for Pu Erh Tea in 1976 for the purpose of export. Each bingcha has 4 digits: the first 2 digits indicate the manufacturing year, the third digit indicates the leaf grade, the last digit indicates the tea factory (e.g. Kun-Ming 1, Meng-Hai 2, Xia-Guan 3, Pu Erh 4). The loose-leaf tea has 5 digits with the third and fourth indicating the class level of raw materials. Examples of early trade numbers for Puerh Tea are 7452, 7562, 7572, 75671, 76563.“