In China, Pu-erh is referred to as ‘Black Tea’ which can be a bit confusing to us Westerners as we use that term to refer to a specific type of tea that is definitely not Pu-erh. What we recognise as black tea is referred to as ‘Red Tea’ by the Chinese. Black tea is oxidised to give the flavour and character; pu-erh is fermented.
Pu-erh is a tea that improves with age through a slow oxidation catalysed by micro-flora on the leaves. There are collectors who will pay silly money for really well aged examples. But with the larger blocks of this tea, it is necessary to be careful, as unscrupulous manufacturers will hide poor quality leaves at the centre with good quality ones on the outside to make it look like you are getting a quality product.
To be called Pu-erh, the tea must be made from the large leafed variety of Camellia Sinensis assamica which grows in the hills of the Yunnan province of China. It was always destined to be an export tea and the locals tended to drink green tea until relatively recently. When the main form of transport was by mule trains, it could take many weeks or even months to export the products from the Yunnan region. Naturally, since teas deteriorate with time, it was necessary for tea producers to develop a method by which their tea could be transported without losing flavour. Thus this type of tea was born.
Essentially, there are two types, raw (also can be referred to as green) and ripe (also can be referred to as black). Raw is what might be classed as the authentic pu-erh since prior to the latter half of the 20th century, only raw was produced and it was aged raw that was bought and sold.
The exact details of the processing of raw pu-erh varies from producer to producer but essentially involves an initial yet optional air drying, pan frying to destroy most of the enzymes thus ensuring the goodness remains in the leaves, rolling and bruising, sun drying and pressing. Not all of the enzymes are destroyed and contribute to the flavour by providing a low level of oxidation during the drying process. Finally, the small amount of moisture left in the leaves triggers the fungi and other microbes to ferment, thus imparting the final character to the tea. If the dried leaves are pressed into cakes for transport and sale, fermentation will take longer than if they are left loose. Loose fermented raw pu-erh tea can be taken to market after 2-3 years.
In the 1970’s, a system was developed where the rolled and dried leaves are then piled loosely in a controlled atmosphere to accelerate the fermentation meaning the tea can hit the market within 6 – 12 months, up to 2 years sooner than with the raw pu-erh tea.
Both types slowly improve with age and 10 years is not an uncommon length of time to leave this tea prior to drinking. It is sold in cakes of various shapes and sizes. In the form of Mushrooms, it is known as Juan Cha; in the form of discs (cakes) it is known as Bing or Beeng Cha; Tuo Cha is a bell shaped block whilst square cakes are known as Fang Cha. The traditional shape is the brick form, Zhuan Cha. Please note that the spellings are an approximation of the sound of the names when spoken in Chinese and different companies may spell them differently.
So there you have it, a brief resume of the complexity and treasure that is Pu-erh tea.