What is pu erh tea?
Pu erh (also known as ‘puer’, ‘bo lay’ or ‘po lei’) is a type of tea made from the Camellia Sinenses tea plant. In fact, all tea including green, white black and oolong tea are made from this same raw material. So you might wonder: what makes them different? And why do they have a different name?
When it comes to tea classification, the key is the processing method applied. So a tea is called pu erh, when one of the pu erh processing methods are used for its production.
Pu erh tea processing
Sha Qing, Fixing & Sun & Drying
When pu erh teas are picked, they’re spread over a bamboo mat to dry and release some moisture. After several hours the leaves will become soft. They’re then ready for roasting in a large round wok, a process that’s also known as ‘sha qing’ or ‘kill green’. In modern times, roasting sometimes is also done in large machines.
During the shaqing process the tea master will control the temperature and time to create unique flavours. Afterwards, the roasted leaves are rolled to fix the shape and intensify the flavour. What follows is sun-drying, which allows the leaves to loose most of its remaining moisture.
The end product of this process is loose raw pu erh tea, which is also known as ‘mao cha’. These dry leaves only have about 25% of the weight compared to when they’re freshly picked.
Mao cha leaves are often sorted before they’re pressed in different shapes or sold loose. Especially the yellow flakes (‘huang pian’) are often removed because of their bad looks. They’re therefore sorted out and sold separately.
Ripe and raw pu erh tea
After the production process above, the raw pu erh might be steamed soft and pressed into compressed raw tea cakes/discs, bowl shaped touchas, or bricks.
Pressing loose leaves into tight shapes was invented in the past for easy transportation. Humans and horses carried pu erh tea along the ancient tea trading routes to neighbouring regions including Tibet. While today, transportation is less of an issue, compressed teas are still preferred for ease of storage.
While raw (sheng) pu erh is made compressing loose mao cha directly into cakes, there’s another type of pu erh that requires post-fermentation before compression: ripe pu erh tea. This type of tea is also known as ‘shu’ or ‘shuo’ pu erh.
The history of ripe pu erh is relatively short. It started in 1973 when the Kunming Tea Factory invented a method to increase the aging process of raw pu erh (mao cha). This method, known as ‘pile fermentation’ (wo dui) was quickly implemented throughout the industry to meet the high demand for pu erh.
The tea masters pile up leaves up to around 70 cm of height in a hot but controlled environment. They’re then dampened with water and cover with linen cloths. By doing this, the mao cha will stay warm and humid. The fermentation speed will increase and the leaves will quickly turn brown. Once the preferred fermentation level has been reached, the now ripe pu erh leaves are turned and spread out thin to dry. They’re now ready to be compressed into different ripe pu erh shapes.
Note that the terms 'ripe' and 'raw' pu erh has nothing to do with aging. They're only terms to distinguish between pu erh that has underwent pile-fermentation (ripe) or not (raw). Both ripe and raw pu erh can be stored and aged.
Origin & grades
Pu erh tea is mainly produced in different regions of the Yunnan province in China. The end product could made from leaves of a single origin or produced from a blend of leaves from different origins. Large factories often produce more blends to keep the taste consistent and allow for large productions, while small producers more often tend to go for single origin productions.
Most of the leaves are produced in natural tea gardens managed by tea growers. However, for some more premium teas, the leaves are plucked from wild arbor trees. The older wild trees are known as ‘gu shu’ or ‘ancient tea trees’.
How to make pu erh tea
Preparing pu erh requires a high and constant temperature of water. Therefore, the use of a small Yixing clay teapot or gaiwan (cup with lid) is highly recommended. These small vessels also allow for brewing small portions of tea over multiple sessions. A great way to enjoy the layers of flavours that makes pu erh tea so fascinating. Read our ‘How to brew pu erh tea’ guide to learn all the ins and outs of tea preparation.
For those who enjoy pu erh, there are luckily also some nice side benefits for the health. It contains caffeine that stimulates the central nervous system, muscles and heart. It contains antioxidants that might protect the heart and blood vessels. At last, it may fight aging, lower cholesterol and reduce the change of cancer. Read our full guide on 'pu erh tea health benefits & side effects'.