Pu-erh is a post-fermented tea made from a large leaf
varietal grown in Yunnan Province. This tea is often aged, which mellows and
refines its flavor and character. It is made either as loose leaf or pressed
into a myriad of shapes; round cakes (bingcha), rectangular bricks and a
birds' nest shape (tuocha) are the most common. Pu-erh can also be
pressed into short lengths of bamboo, then dried and stored- a specialty of the
Dai people in Xishuangbanna.
Pu-erh has traditionally been savored in Hong Kong, Guangdong
Province and Taiwan; other post-fermented teas are also made elsewhere in
China as well as in Burma, Thailand, Laos, Vietnam and Japan.
There are two main steps in production: The first is making a
base tea (mao cha), and the second is post-fermenting and often
compressing it. Pu-erh produced before the 1970s was made from sun-dried green
tea and naturally aged, a process that is now known as sheng, green
or raw. In 1973, a technique for accelerating the process of aging and changing
the character of the tea was developed by the Kunming Factory. This process is
called wo dui and involves increasing the moisture level as
well as the temperature of the tea to speed up the fermentation. These pu-erhs
are referred to as shu, brown or cooked pu-erh.
Sheng Pu-erh (green or raw)
Present-day style – not post-fermented
Old style – post-fermented by dry storage method
Both methods benefit from extended aging, as it will change the
color of the tea as well as the character.
Shu Pu-erh (black or cooked)
Mao cha is subjected to controlled levels of humidity and heat
to hasten the fermentation of the leaves. The increased moisture generates
heat within the pile naturally; in the same way that freshly picked green
leaves generate heat within a pile.
One recipe is as follows:
Pile the tea and spray it with water until the moisture level is
After six to seven days, turn the pile (60-70 C) for the first
After six to seven days, turn the pile (50-60 C) for the second
After another 6-7 days turn the pile (40-50 C) for the final
Solar drying (one day).
Other recipes lengthen this wo dui process to 50-60 days.
Aspergillus is the main bacteria present which helps to transform the
leaf in a very complex chemical change.
Heat is produced when the leaf is piled, similar to what makes
barns catch fire after being filled with freshly made hay bales.
After several fermentations (turning the piles of tea and
letting them sit for weeks at a time) the tea may be compressed or left loose.
The tea to be compressed is weighed, steamed, and pressed.
This is one reason that areas like Hong Kong and Taiwan, both of
which have very humid climates, are considered good places to store pu-erh and
indeed, a considerable amount is hoarded there to drink in the future.
“Artificial wet storage” is similar to wo dui except instead of a more delicate hastening of the natural
process, it's a much more abrupt process of drenching the leaf to make the
final product appear more mature and aged than it actually is. This is the
process by which fake pu-erh is made.