When I first got into tea, I thought I hated puerh. Part of that was because the first examples I tried were extraordinarily terrible. My revelation came when I discovered sheng, aka raw puerh. My taste buds did a happy dance. There was stuff that didn't taste like fish and dirt! That was many years ago and I've come to enjoy shu as well. I wish someone had explained all of these nuances to me way back when so I thought it might be fun to put a post together that compares the two.
Yunnan is a fascinating region and the one that I probably enjoy learning about the most. It is the most biologically diverse part of China. Many believe it to be the birthplace of the tea plant, Camellia Sinensis. Each of the mountain areas that produce tea have a distinctive style and taste. Some of the trendier and higher demand regions are all but impossible for the average tea drinker to obtain. Yunnan is also home to twenty-five recognized minority ethnic groups. Each of these groups has their own histories and culture, many of which revolve around tea.
It can be difficult to find historical tea information in English. We do know that tea has been grown in Yunnan since at least the Tang Dynasty. Compressed tea was used as currency in China, Tibet, and Russia. The tea of Yunnan was also traded for horses along the Tea Horse Road with Tibet. If you'd like to find out more of this history, I highly recommend Puer Tea: Ancient Caravans and Urban Chic by Jinghong Zhang and The Ancient Tea Horse Road by Jeff Fuchs. For the majority of its history, all puerh was of the greener raw variety.
The important thing to understand here is that there was no emphasis on aging tea like we have now. When demand for aged puerh did rise, a method of speeding up the fermentation process was invented. There were experimental batches as early as the 1950's but the process was not refined until the 1970's. The Menghai and Kunming Tea Factories usually take credit for this discovery. The basic principles were borrowed from Guangxi's Liu Bao, also a type of fermented tea.
Sheng, also known as raw puerh, is processed very similarly to green tea. The leaves are briefly pan fried before being rolled and laid out in the sun to dry. Unlike the kill-green step that is used for most teas, the goal is to slow down oxidation to a snail's pace. This allows the tea to age slowly over time. If there is too much heat applied the tea will not age as desired. Once dried the tea is called mao cha, or rough tea. It can be left loose but is most often compressed into cakes or bricks.
Shu, also known as cooked puerh, is artificially fermented in order to achieve a dark and earthy taste. You may also see it referred to as ripe. The name is a bit of a misnomer as there is no "cooking" being done to the tea. During the process known as Wò Dūi the tea is piled, moistened with water, and continually turned. This combined with beneficial bacteria like Aspergillus Niger effectively makes a tea compost. The process takes about a month to complete. Afterward, the leaves are dried and then either kept loose or compressed.
Shu puerh, on the other hand, has an earthy and woodsy taste. Mushroom is the tasting note that I hear most often but I've had teas that taste like cacao and brown sugar too. One of the things I enjoy the most about this type of tea is that they usually have soothing natural sweetness. Cooked puerh brews up extremely dark and it's often even darker on the second infusion. Beware a poor quality tea (aka anything you'll find on the shelf of the local Asian grocery). They will most assuredly taste like a mushroom infested swamp.
Are you more of a sheng or shu person? Let me know in the comments!