Pu’er tea, a well-known traditional Chinese tea, has been categorized as sun-driedgreen tea, and its pressed products from large tea leaves (Camellia sinensis O. kuntzevar. assamica Kitamura) are manufactured mainly in Yunnan, China. In the markets,three kinds of pu’er teas have been sold: loose pu’er tea, pressed pu’er tea,and pu’er tea bags.Pu’er tea is a popular tea with a long history, which originated from the districtsof Xi-shuang-ban-na(西双版纳州), Si-mao(思茅), and Lan-chuang-jiang valley(澜沧江), Yunnan Province(云南省),China.
There are two manufacturing procedures that have been widely employed forproduction of pu-erh tea: the classical pressing method and the wet-piling method.The former dates back to the Tan Dynasty (864–1278 a.c.), while the latter has beendeveloped recently (1938 a.c. to present).
The Classical Pressing Method
The classical pressing method includes seven steps as described below:
Step 1. Plucking of fresh tea leaves. The best fresh tea leaves are plucked in the early spring (March). The tea leaves plucked in the middle of spring (April)and late spring (May) are still good for making pu’er tea.
Step 2. Blanching. The fresh tea leaves harvested in step 1 should be subjected toa blanching process as soon as possible by baking on a hot pan with constantmanual mixing. As soon as tea leaves become very soft and liberate a uniquegrass fragrance, the blanching process should be stopped at once.
Step 3. Rolling. The purpose of rolling is to liberate the juice of the tea leavesto the outside of the leaf surface. Thus, the flavor of the tea leaves willbe released easily when brewing with hot water.
Step 4. Sun drying. The rolled tea leaves are dried under sunlight with constantmixing. The heat and infrared rays from sunlight penetrate the tea leavesand remove the moisture as well as promote chemical reactions in the leafmatrix. This process takes two working days to accomplish.
Step 5. Storage in a dry place. The dried raw tea is packed in a large, clean gunnybag and stored in a temperature- and humidity-controlled stockroom.
Step 6. Pressing into different shapes.
Step 7. Long-term incubation for ripening. This step is essential for makinggood-quality pu’erh tea. It is a general rule that the longer the storage, the better the quality of pu’er tea.
The wet-piling method has recently been developed; the initial four steps are similarto those described in the classical pressing method:
Step 1. Plucking. As described in step 1 above.Step 2. Blanching. As described in step 2 above.
Step 3. Rolling. As described in step 3 above.
Step 4. Sun drying. As described in step 4 above.
Step 5. Fermentation by wet piling. In the process of pu-erh tea manufacturing,both enzymatic and nonenzymatic oxidations play a very important role inthe transformation of tea components. These oxidation reactions take placevery slowly and persistently. Furthermore, oxidation is assisted by environmentalmicrobes and oxygen.
Step 6. Repiling and mixing. The temperature and moisture of the piles areessential for determining the degree of fermentation and are important factorsaffecting the quality of pu’er tea. The temperature and moisture of theincubation room and tea piles are strictly controlled. The tea piles should bebroken down, mixed, and piled up again every 2 days. More water shouldbe showered during the repiling and mixing process. It takes five to eightrepetitions of repiling and mixing to accomplish the fermentation process.
Step 7. Air drying. The fermented piled tea products are broken down andseparated into several valleys for air drying (not sun drying). The watercontent of piled tea products is around 20%, but is reduced to 14–20% uponair drying. The tea mass is then broken down and separated into severalnew valleys again every 3–5 days. The air-drying process is repeated againand again until the moisture of the tea product reaches 14%.
Step 8. Selection and grouping. The air-dried tea products are subjected to strictselection and grouping based on their color, size, fragrance, and appearance.
Step 9. Packaging and pressing. The selected air-dried tea products are packedin a gunnysack and stored in a dried stock room. The air-dried tea productscould also be pressed into different shapes, such as cubic, brick, bowl, andring cake, and then stored in a stock room.
Edited by Ziwei Chen/陈紫薇