Pu-erh tea can be purchased as either raw/green (sheng) or ripened/cooked (shou), depending on processing method or aging. Sheng pu-erh can be roughly classified on the tea oxidation scale as a Green Tea, and the shou or aged-green variants as post-fermented tea. The fact that pu-erh fits in more than one tea type poses some problems for classification. For this reason, the “green tea” aspect of pu-erh is sometimes ignored, and the tea is regarded solely as a post-fermented product. Unlike other teas that should ideally be consumed shortly after production, pu-erh can be drunk immediately or aged for many years; pu-erh teas are often now classified by year and region of production much like wine vintages.
While there are many counterfeit pu-erhs on the market and real aged pu-erh is difficult to find and identify, it is still possible to find pu-erh that is 10 to 50 years old, as well as a few from the late Qing Dynasty. Indeed, tea connoisseurs and speculators are willing to pay high prices for older pu-erh, upwards of thousands of dollars per cake.
Pu-erh tea is available as loose leaf or as cakes of compacted tea (see Tea brick).
Preparation of pu-erh involves first separating a well-sized portion of the compressed tea for brewing. This can be done by flaking off pieces of the cake or by steaming the entire cake until it is soft from heat and hydration. A pu-erh knife, which is similar to an oyster knife or a rigid letter opener, is used to pry large horizontal flakes of tea off the cake such as to minimize leaf breakage. Steaming is usually performed on smaller teas such as tuocha or mushroom pu-erh and involves steaming the cake until it can be rubbed apart and then dried. In both cases, a vertical sampling of the cake should be obtained since the quality of the leaves in a cake usually varies between the surface and the center of the cake.
Pu-erh is generally expected to be served Gongfu style, generally in Yixing teaware or in a type of Chinese teacup called a gaiwan. Optimum temperatures are generally regarded to be around 95 degree Celsius for lower quality pu-erhs and 85-89 degree Celsius for good ripened and aged raw pu-erh. Steeping times last from 12-30 seconds in the first few infusions, up to 2-10 minutes in the last infusions. The prolonged steeping techniques used by some western tea makers can produce dark, bitter, and unpleasant brews. Quality aged pu-erh can yield many more infusions, with different flavour nuances when brewed in the traditional Gong-Fu method.
Because of the prolonged fermentation in ripened pu-erh and slow oxidization of aged raw pu-erh, these teas often lack the bitter, astringent properties of other tea types, and also can be brewed much stronger and repeatedly, with some claiming 20 or more infusions of tea from one pot of leaves. On the other hand, young raw pu-erh is known and expected to be strong and aromatic, yet very bitter and somewhat astringent when brewed, since these characteristics are believed to produce better aged raw pu-erh.