Pu erh, the fermented tea of Yunnan

Pu erh tea is a tea from Yunnan, in south-west China, with a feature that no other major family of tea shares: after it is made, it ferments, through the action of micro-organisms. There are two kinds, raw pu erh (sheng), which changes slowly as it ages, and ripe pu erh (shou), whose fermentation is sped up to a few weeks. It is found pressed into cakes or bricks, and loose too. It is one of the few teas that people deliberately keep for years.

Here is where it comes from, how it is made, and how to brew it.

A tea from Yunnan, and only from Yunnan

The name comes from Pu'er, an old tea-trading town in the south of the province, today Ning'er. The leaves come from the large-leaf variety of the tea plant, Camellia sinensis var. assamica, grown in Yunnan: the same species as for all other teas.

The name is protected. In late 2008, China adopted a standard making it a geographical indication: only tea produced in defined areas of Yunnan may be called pu erh. The European Union protects it too: "Pu'er Cha" is one of the Chinese geographical indications covered by the agreement between the European Union and China that came into force on 1 March 2021. The defined area covers a large part of the province, including the regions of Pu'er, Xishuangbanna and Lincang.

Maocha: a start close to green tea

Every pu erh begins as a base tea, maocha. The picked leaves are heated in a wok to stop most of the activity of their enzymes, as for a green tea. They are then rolled, and dried in the sun.

This sun-drying makes a first difference. The heating has not stopped everything: a little enzyme activity remains in the leaf, which oxidises it slightly as it dries. So maocha is not quite a green tea, even if it is close to one.

From there, two paths open up. We have summed up what sets these processes apart from those of green and black tea in an article on the three families; here, let us take a closer look at pu erh.

Sheng and shou: raw or ripe

Raw pu erh, or sheng, is maocha as it is, sold loose or pressed. Young, it is powerful and aromatic, but also frankly bitter and somewhat astringent. Time is what transforms it: over the years, the cup becomes darker and softer, and takes on the notes of earth and forest floor that old pu erh is known for.

Ripe pu erh, or shou, takes a shortcut. In 1973, the Kunming tea factory developed wo dui, a pile fermentation. The maocha is heaped up and moistened, then monitored and turned as the pile heats up, over several weeks. Moulds, chief among them those of the genus Aspergillus, play a major role. The aim is to come close, in a few weeks, to what ageing does to sheng over several years.

Shou does not replace an old sheng, but it has a character of its own: a dark brown, round liquor with notes of damp earth and wood. The word "post-fermented", seen on labels, refers to this fermentation that takes place after the base tea has been made.

Cakes, nests and bricks: a pressed tea

Pu erh is one of the few teas that are pressed. The tea is first lightly steamed, which softens the leaves and makes them a little sticky, then compressed, with a hydraulic press in most factories, with a stone in more artisanal workshops. The most common shapes:

• the cake (bing cha), a flat disc, most often 357 g, sometimes 400 or 500 g; they are stacked in sevens in a wrapping of bamboo leaves or thick paper, the tong;
• the nest (tuo cha), a bowl shape, often from 100 to 500 g;
• the brick (zhuan cha), a rectangular block, the traditional shape of the tea that horse caravans carried along the old tea routes;
• the mushroom (jin cha), a nest with a stem, long produced for Tibet.

In many cakes, a small ticket is pressed in with the leaves, the nei fei, which serves as a sign of authenticity. To serve yourself, you prise leaves from the edge of the cake with a pick or a pu erh knife.

Pu erh is also sold loose, without going through the press. That is the case with our Pu Erh d'origine tea: a post-fermented, plain tea with nothing added, giving a dark, round cup with woody and earthy notes. No cutting, and easier to measure.

A tea that ages

Most teas are drunk young. Sheng, on the other hand, is made to last: it is as it ages that it loses the bitterness of its youth and gains roundness.

Where it is stored changes the result. A distinction is made between so-called dry storage, at moderate temperature and humidity, where the tea changes slowly, and wet storage, in hot, humid climates such as those of Hong Kong or Guangzhou, where it changes faster and differently. Two cakes from the same batch, one kept in Yunnan and the other in Hong Kong, do not give the same cup after a few years.

Shou also changes over time, but there is less at stake, since wo dui has already done a good part of the work. Some collectors feel there is no point keeping it for more than about ten years; others find new nuances in it with age.

How to brew pu erh tea

There are two ways of going about it.

Western style, as given on the page for our Pu Erh d'origine: 12 g per litre, about 3 g for a 250 ml cup, water at 100 °C, and 4 to 5 minutes of infusion.

Chinese style, in a small teapot, with many more leaves and very short infusions: around 12 to 30 seconds for the first, then a few seconds more each time.

Either way, two steps come up again:

• The rinse. Pour hot water over the leaves, throw it away after about ten seconds, then brew as usual. The cup will be cleaner, and the damp-earth note less pronounced if it surprises you at first.
• Successive infusions. Do not throw the leaves away after the first cup: our pu erh takes 3 to 4 infusions, lengthening the time slightly each time. Many enthusiasts find the second better than the first.

Pu erh needs boiling water, and it is better with water low in limescale: we explain why in our article on water for tea. The settings for all our families of tea are gathered in the guide how to brew loose tea.

Frequently asked questions

What is the difference between raw and ripe pu erh?
Raw (sheng) ferments slowly, over an ageing process that can last years. Ripe (shou) goes through an accelerated pile fermentation, wo dui, developed in 1973. Young, the first is lively and bitter; the second is dark and round from the start.

Is pu erh a black tea?
No. Black tea is oxidised by the enzymes in its own leaf; pu erh is fermented by micro-organisms, after a first stage close to that of green tea.

Is this earthy taste normal?
Yes, it is the signature of pu erh, not a fault. If you find it too pronounced, rinse the leaves for about ten seconds before the first infusion.

Does pu erh contain theine (caffeine)?
Yes, like all teas from the tea plant. Theine is the same molecule as caffeine, and rinsing removes very little of it: we go into detail in our article on theine and caffeine.

To go further, our Pu Erh d'origine is waiting for you in the loose teas and infusions collection. For another cup with character, this time on a black tea base, try Âme de Sri Lanka, a spiced Ceylon OP.