The world of tea is not scientific; it is nebulous and vague. The distinctions between different types of teas are complex and Byzantine, calling into play not only genetics and processing styles but region, history, seasonality, picking styles and tradition. This is especially true in China, the home of tea, where origins of many teas are shrouded in conflicting legends, and every tea farmer or master claims that their particular way of doing things represents the “orthodox” and original style. China is vast and ancient, and a tea that is famous and celebrated in one place might be completely unknown in other regions. One tea might be called by varying names in different places while teas that have nothing to do with each other happen to share a name. This confusion is amplified in translation, resulting in vast misconceptions in America about what qualifies the different types of Chinese teas, where they come from, and how they are made. I just returned from three months in China where I expanded my knowledge of Chinese tea many times over, but, as always, this improved “map” of Chinese tea culture only serves to reveal how little I know about this broad and complex subject.
One of the most popular teas right now in both China and the West is pu er tea, an ancient variety from Yunnan in southwestern China. In spite of its popularity, or perhaps because of it, it is one of the most ill-served in terms of clarity and consistency in the information currently available about it. It is my hope in this series to share my own understanding of pu er, based on my experiences in Yunnan, and in doing so shed some light on this “dark” tea.
What is Pu Er?
The simple answer is that pu er is a type of tea from Yunnan, in Southwestern China, made from a variety of tea plants that represents the oldest cultivated varietal. American tea lovers often consider pu er to be a “category” of tea, taxonomically on equal footing with green tea, black tea, white tea, etc. In this scheme, pu er is distinguished from other teas in that it is post-fermented – that is, subjected to a secondary microbial aging process that alters the characteristics of the tea. By this definition, all post-fermented teas, of which there are many – liubao, liu’an, qingzhuan, etc – would be considered “types” of pu er regardless of which region or variety of plant they come from. This is akin to saying that a pear is a type of apple. In reality, fermented pu er and the other post-fermented teas belong to a broader region-independent category called “heicha”, which literally translates as “black tea”, but is known in English as “dark tea” (the oxidized “black tea” we are familiar with in the West is called “red tea” in China, a term reserved in English for rooibos, which is not tea at all. I told you it was confusing.) So that means that pu er is a type of heicha, right? Not exactly.
Sheng, Mao, Cheng, and Shu
Not all pu er is heicha because not all pu er is fermented. Fresh pu er that is processed by wok-roasting and sun-drying is called mao cha and is not fermented. It is still pu er, but it may also be considered a variety of green tea. As the leaves age, they are broken down by microbes, mostly Aspergillus yeast, developing a dark color and an earthy flavor. This process is hastened by warmth and humidity. Aged tea that has undergone this change is called cheng cha, “mature tea”. In 1972, a technique for replicating this aging was invented, called the ‘wo dui’ process, in which piles of finished mao cha are moistened and turned, essentially composting the leaves. This is called shu cha, or “ripened” tea.
The traditional dry-aged style of pu er that has not been “ripened” is called sheng. Sheng is often translated as “raw” but also means “alive”, which is a somewhat better term because sheng pu er is in fact cooked as the first step of its processing. The leaves, sheng or shu, can be stored loose or pressed into a variety of shapes, mostly bricks and discs. So in summary: Fresh, unripened loose leaves are mao cha. Fresh, unripened pu er in general, whether loose or otherwise, is called sheng cha. Pu er that has been ripened through wet-aging is called shu cha. Aged tea, regardless of its processing style, is called cheng cha. Both shu cha and cheng cha can be considered heicha, because they are fermented naturally or artificially. Mao cha and pressed sheng cha are not considered heicha because they are still green, but would, in fact, be considered pu er.
Ancient Trees, Big Leaves
Yunnan is the biological home of the tea plant in China, and the variety from which pu er is made is very close to the ancestral wild-type. The quality of tea from these plants is dependent on the altitude at which they are grown, the purity of their environment, the presence of clouds and mist, and the age of the tree itself. Since all but the last category hold true for all classes of tea, let us focus on the latter. The oldest cultivated tea trees in the world are in Yunnan, though which are oldest and how old exactly they are is a matter of debate which I am not qualified to participate in. The trees on Nannuo mountain, where I source my pu er, are around 800 years old, with some that may be older but not verifiably so. Tea from these old trees is known as Gu Shu Cha, “ancient tree tea”. I’m told the minimum age to qualify as gu shu cha is 300 years, but it may depend on whom you ask. Gu shu cha is always seed propagated, meaning that each individual plant is a genetically distinct “variety”, with a great diversity in their individual characteristics. This ancient tree tea is considered the highest grade of pu er tea. The leaves from ancient trees are usually sold as mao cha, though they are sometimes pressed, and very rarely “ripened” into shu pu er. The reason for this is two-fold: one is that the ripening process produces a great deal of waste, as the leaves break up as they are turned, resulting in lower-grade leaves and a greater amount of tea dust. Another reason is that pu er connoisseurs in Yunnan (and most of the southwest) rarely, if ever, drink shu cha, preferring sheng. This extremely expensive ancient tree tea is obviously marketed to connoisseurs.
Small, young plants that are seed-propagated or more typically cloned, grown in rows for large-scale production, are called taidi cha, while medium-aged plants – several decades to a few centuries old – are called qiao mu (bridge wood) if they grow from a single straight trunk or guan mu (bush wood) if they grow from multiple shrubby branches. Low-quality tea grown in valleys is called bazi cha and is usually young, cloned plants. This tea is the lowest grade of pu er because the low altitude plants are more susceptible to insects, and thus more frequently treated with pesticides.
Da Ye “Big Leaf” tea does not refer to the actual size of the leaves but to one of the two main “breeds” or pu er tea plant that grow in Yunnan. The other is xiao zhong ye, “small medium leaf”. Generally speaking, the region west of the Lancang (Mekong) river is dominated by Da Ye plants, while the east of the Lancang is dominated by Xiao Zhong Ye.
Though the leaves of Da Ye plants tend to be bigger, both varieties are capable of producing both big and small leaves. Likewise, you cannot tell if a tea is Gu Shu cha just by looking at the leaf size. Ancient trees are all distinct from each other and have a variety of phenotypes, such that a 300-year old tree could produce much larger leaves than an 800-year old tree. Leaves growing further down the trunk, or from new branches, are also smaller than those at the top of the tree, although no less ancient. Furthermore, young plants are often treated with growth hormone to produce large buds and leaves that are sold as ersatz gu shu cha. How to tell true from false gu shu cha is an article unto itself.
“Pu Er to the people” is a two-part series on Pu Er teas. The next installment will be posted next week.
Photos courtesy of So Han Fan, of West China Tea Company.