thumb|A lump of royal tribute pu'er tea produced during the [[Guangxu Emperor period (1875–1908) was collected in Forbidden City and moved to Pu'er City Museum in 2007.]]
thumb|Shú pu'er tea, shúchá, brewed from a brick
Pu'er or pu-erh<!--Chinese in infobox; see WP:MOS-ZH.--> is a variety of fermented tea traditionally produced in Yunnan Province, China. Pu-erh tea is made from the leaves of the Yunnan tea plant Camellia sinensis var. assamica,which is a specific variety of tea plant that is native to Yunnan. It differs from Yunnan tea (dianhong) in that pu'er tea goes through a complex fermentation process. In the context of traditional Chinese tea production terminology, fermentation refers to microbial fermentation (called 'wet piling'), and is typically applied after the tea leaves have been sufficiently dried and rolled. As the tea undergoes controlled microbial fermentation, it also continues to oxidize, which is also controlled, until the desired flavors are reached. This process produces tea known as hēichá (黑茶), literally "black tea", though the term is commonly translated to English as "dark tea" to distinguish it from the English-language "black tea" (紅茶/红茶 hóngchá, lit. "red tea" in Chinese), which it is not.
Most teas, although described as fermented, are actually oxidised by enzymes present in the tea plant. Pu'er is instead fermented microbially by molds, bacteria and yeasts present on the harvested leaves of the tea plant, and thus is truly fermented.
There are two main styles of pu'er production: a traditional, longer production process known as shēng ("raw") pu'er; and a modern, accelerated production process known as shóu ("ripe") pu'er. Pu'er traditionally begins with a raw product called "rough" (máo) chá (毛茶, lit. fuzzy/furry tea) and can be sold in this form or pressed into a number of shapes and sold as shēng chá (生茶, lit. raw tea). Both of these forms then undergo the complex process of gradual fermentation and maturation with time. The wòduī (渥堆) fermentation process developed in 1973 by the Kunming Tea Factory created a new type of pu'er tea. This process involves an accelerated fermentation into shóu (or shú) chá (熟茶, lit. ripe tea) that is then stored loose or pressed into various shapes. The fermentation process was adopted at the Menghai Tea Factory shortly after and technically developed there. The legitimacy of shóu chá is disputed by some traditionalists when compared to the traditionally longer-aged teas, such as shēng chá.
Pu'er can be stored and permitted to age and to mature, like wine, in non-airtight containers before consumption. This is why it has long been standard practice to label all types of pu'er with the year and region of production.
Name
Pu'er is the pinyin romanization of the Mandarin pronunciation of Chinese Pu-erh is a variant of the Wade–Giles romanization (properly p'u-êrh) of the same name. In Hong Kong, the same Chinese characters are read in Cantonese as Bo-lei, and this is therefore a common alternative English term for this tea. The tea got its name from the ancient tea-trading town of Pu'er (普洱), which is modern Ning'er Town (宁洱镇) in Ning'er Hani and Yi Autonomous County, Pu'er City, Yunnan Province. Pu'er County had its name changed to Simao, after Simao Town, the new county seat in 1950 following the proclamation of the People's Republic of China. The county of Simao became a prefecture-level city and had its name changed to Pu'er in 2007. Although the urban center of the modern Pu'er City remained in Simao, the whole Pu'er region is now sometimes considered the appellation for Pu'er proper.
History
Fermented tea leaves have had a long history among ethnic groups in southwest China. These crude teas were of various origins and were meant to be low cost. The Bulang and Dai people of Yunnan Province have produced pu'er tea at Jingmai Mountain since at least the 10th century. Traditionally, the tea trees would be planted in the forest understory after some larger trees were removed. On the border of these old tea forests, a partition forest would be planted to protect against the spread of pests and diseases, with cultivated land for crops and vegetables at lower altitudes. This new process produced a finished product in a matter of months that many thought tasted similar to teas aged naturally for 10–15 years, so this period saw a demand-driven boom in the production of hēichá by the artificial ripening method.
In recent decades, demand has come full circle and it has become more common again for hēichá, including pu'er, to be sold as the raw product without the artificial accelerated fermentation process.
Processing
Pu'er tea processing, although straightforward, is complicated by the fact that the tea itself falls into two distinct categories: the "raw" shēngchá and the "ripe" shóuchá. All types of pu'er tea are created from máochá (毛茶), a mostly unoxidized green tea processed from Camellia sinensis var. assamica, which is the large leaf type of Chinese tea found in the mountains of southern and western Yunnan (in contrast to the small leaf type of tea used for typical green, oolong, black, and yellow teas found in the other parts of China).
Máochá can be sold directly to market as loose leaf tea, compressed to produce "raw" shēngchá, naturally aged and matured for several years before being compressed to also produce "raw" shēngchá or undergo wòduī ripening for several months prior to being compressed to produce "ripe" shóuchá. While unaged and unprocessed, Máochá pǔ'ěr is similar to green tea. Two subtle differences worth noting are that pǔ'ěr is not produced from the small-leaf Chinese varietal but the broad-leaf varietal mostly found in the southern Chinese provinces and India. The second is that pǔ'ěr leaves are picked as one bud and 3-4 leaves whilst green tea is picked as one bud and 1-2 leaves. This means that older leaves contribute to the qualities of pǔ'ěr tea.
Ripened or aged raw pǔ'ěr has occasionally been mistakenly categorized as a subcategory of black tea due to the dark red color of its leaves and liquor. However, pǔ'ěr in both its ripened and aged forms has undergone secondary oxidization and fermentation caused both by organisms growing in the tea and free-radical oxidation, thus making it a unique type of tea. This divergence in production style not only makes the flavor and texture of pu'er tea different but also results in a rather different chemical makeup of the resulting brewed liquor.
The fermented dark tea, hēichá (黑茶), is one of the six classes of tea in China, and pǔ'ěr is classified as a dark tea (defined as fermented), something which is resented by some who argue for a separate category for pǔ'ěr tea. As of 2008, only the large-leaf variety from Yunnan can be called a pǔ'ěr.
Pu'er is typically made through two steps. First, all leaves must be roughly processed into maocha to stop oxidation. From there it may be further processed by fermentation, or directly packaged. Summarising the steps: On overcast or rainy days, the leaves will be wilted by light heating, a slight difference in processing that will affect the quality of the resulting maocha and pu'er.
upright=0.68|thumb|Relatively young raw pu'er; note the grey and dark green tones
The leaves are then dry-roasted using a large wok in a process called "killing the green" (殺青; pinyin: shā qīng), which arrests most enzyme activity in the leaf and prevents full oxidation.
Pressing can be done by:
- A press. In the past, hand lever presses were used, but were largely superseded by hydraulic presses. The press forces the tea into a metal form that is occasionally decorated with a motif in sunken-relief. Due to its efficiency, this method is used to make almost all forms of pressed pu'er. Tea can be pressed either with or without it being bagged, with the latter done by using a metal mould. Tightly compressed bǐng, formed directly into a mold without bags using this method are known as tié bǐng (鐵餅, literally "iron cake/puck") due to its density and hardness. The taste of densely compressed raw pu'er is believed to benefit from careful aging for up to several decades.
- A large heavy stone, carved into the shape of a short cylinder with a handle, simply weighs down a bag of tea on a wooden board. The tension from the bag and the weight of the stone together give the tea its rounded and sometimes non-uniform edge. This method of pressing is often referred to as: "hand" or "stone-pressing", and is how many artisanal pu'er bǐng are still manufactured.
Pressed pu'er is removed from the cloth bag and placed on latticed shelves, where they are allowed to air dry, which may take several weeks or months, depending on the wetness of the pressed cakes.
Pu'er undergoes what is known as a solid-state fermentation where water activity is low to negligible. Both endo-oxidation (enzymes derived from the tea-leaves themselves) and exo-oxidation (microbial catalysed) of tea polyphenols occurs. The microbes are also responsible for metabolising the carbohydrates and amino acids present in the tea leaves. Although the microbes responsible have proved highly variable from region to region and even factory to factory, the key organism found and responsible for almost all pu'er fermentation has been identified in numerous studies as Aspergillus niger, with some highlighting the possibility of ochratoxins produced by the metabolism of some strains of A.niger having a potentially harmful effect through consumption of pu'er tea. It is apparent that this species does not have the gene sequence for coding ochratoxin and thus pu'er tea should be considered safe for human consumption.
Ripe and raw pu'er
"Ripened" Shu Cha (熟茶) tea is pressed maocha that has been specially processed to imitate aged "raw" Sheng Cha tea. Although it is also known in English as cooked pu'er, the process does not actually employ cooking to imitate the aging process. The term may be due to inaccurate translation, as shóu (熟) means both "fully cooked" and "fully ripened".
The process used to convert máochá into ripened pu'er manipulates conditions to approximate the result of the aging process by prolonged bacterial and fungal fermentation in a warm humid environment under controlled conditions, a technique called wò duī (渥堆, "wet piling" in English), which involves piling, dampening, and turning the tea leaves in a manner much akin to composting. Poor control in fermentation/oxidation process can result in bad ripened pu'er, characterized by badly decomposed leaves and an aroma and texture reminiscent of compost. The ripening process typically takes between 45 and 60 days on average.
The wò duī process was first developed in 1973 by Menghai Tea Factory and Kunming Tea Factory
Classification
Aside from vintage year, pu'er tea can be classified in a variety of ways: by shape, processing method, region, cultivation, grade, and season.
Shape
Pu'er is compressed into a variety of shapes. Other lesser seen forms include: stacked "melon pagodas", pillars, calabashes, yuanbao, and small tea bricks (2–5 cm in width). Pu'er is also compressed into the hollow centers of bamboo stems or packed and bound into a ball inside the peel of various citrus fruits (Xiaoqinggan) or sold as nuggets (Suiyinzi 碎银子 or fossilized tea 茶化石) or bundles made from tea at the center of wet piles (Laotoucha 老头茶).
{| class="wikitable"
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! rowspan="2" ; | Image
! rowspan="2" ; | Common name
! colspan="2" ; | Chinese characters
! rowspan="2" ; | Pinyin
! rowspan="2" ; | Description
|-
!S
!T
|-
| 150px|upright=0.68
|Bing, Beeng, Cake, or Disc
| 饼茶
| 餅茶
| Bǐngchá
| A round, flat, disc or puck-shaped tea, the size ranges from as small as 100 g to as large as 5 kg or more, with 357 g, 400 g, and 500 g being the most common. Depending on the pressing method, the edge of the disk can be rounded or perpendicular. It is also commonly known as Qīzí bǐngchá (七子餅茶, Chi Tsu Ping Cha, Chi Tse Beeng Cha, literally "seven units cake tea") because seven of the bing are packaged together at a time for sale or transport.
|-
| 150px|upright=0.68
|Tuocha, Bowl, or Nest
| 沱茶
| 沱茶
| Tuóchá
| A convex knob-shaped tea, its size ranges from 3 g to 3 kg or more, with 100 g, 250 g and 500 g being the most common. The name for tuocha is believed to have originated from the round, top-like shape of the pressed tea or from the old tea shipping and trading route of the Tuo River. In ancient times, tuocha cakes may have had holes punched through the center so they could be tied together on a rope for easy transport.
|-
| 150px|upright=0.68
| Brick
| 砖茶
| 磚茶
| Zhuānchá
| A thick rectangular block of tea, usually in 100 g, 250 g, 500 g and 1000 g sizes; Zhuancha bricks are the traditional shape used for ease of transport along the ancient tea route by horse caravans.
|-
| 150px|upright=0.68
| Square
| 方茶
| 方茶
| Fāngchá
| A flat square of tea, usually in 100 g or 200 g sizes. Characters are often pressed into the square, as in the example illustrated.
|-
| 150px|upright=0.68
| Mushroom
| 紧茶
| 緊茶
| Jǐnchá
| Literally meaning "tight tea," the tea is shaped much like a 250 g to 300 g túocha, but with a stem rather than a convex hollow. This makes them quite similar in form to a mushroom. Pu'er tea of this shape is generally produced for Tibetan consumption.
|-
| 150px|upright=0.68
| Dragon Pearl
| 龙珠
| 龍珠
| Lóngzhū
| A small ball-shaped or rolled tea, convenient for a single serving. Generally balls contain between 5 and 10 grams of compressed material. The practice is also common among Yunnan black tea and scented green teas.
|-
| 150px|upright=0.68
| Gold Melon
| 金瓜
| 金瓜
| Jīnguā
| Its shape is similar to tuóchá, but larger in size, with a much thicker body decorated with pumpkin-like ribbing. This shape was created for the "Tribute tea"(貢 茶) made expressly for the Qing dynasty emperors from the best tea leaves of Yiwu Mountain. Larger specimens of this shape are sometimes called "human-head tea" (人 頭 茶), due in part to its size and shape, and because in the past it was often presented in court in a similar manner to severed heads of enemies or criminals.
|}
Process and oxidation
Pu'er teas are often collectively classified in Western tea markets as post-fermentation, and in Eastern markets as black teas, but there is general confusion due to improper use of the terms "oxidation" and "fermentation". Typically black tea is termed "fully fermented", which is incorrect as the process used to create black tea is oxidation and does not involve microbial activity. Black teas are fully oxidized, green teas are unoxidized, and Oolong teas are partially oxidized to varying degrees.
All pu'er teas undergo some oxidation during sun drying and then become either:
- Fully fermented with microbes during a processing phase which is largely anaerobic, i.e. without the presence of oxygen. This phase is similar to composting and results in Shu (ripened) pu'er
- Partly fermented by microbial action, and partly oxidized during the natural aging process resulting in Sheng (raw) pu'er. The aging process depends on how the sheng pu'er is stored, which determines the degree of fermentation and oxidization achieved.
According to the production process, four main types of pu'er are commonly available on the market:
- Maocha, green pu'er leaves sold in loose form as the raw material for making pressed pu'er. Badly processed maocha will produce an inferior pu'er.
- Green/raw pu'er, pressed maocha that has not undergone additional processing; high quality green pu'er is highly sought by collectors.
- Ripened/cooked pu'er, maocha that has undergone an accelerated fermentation process lasting 45 to 60 days on average. Badly fermented maocha will create a muddy tea with fishy and sour flavors indicative of inferior aged pu'er.
- Aged raw pu'er, a tea that has undergone a slow secondary oxidation and microbial fermentation. Although all types of pu'er can be aged, the pressed raw pu'er is typically the most highly regarded, since aged maocha and ripened pu'er both lack a clean and assertive taste.
Flavour
Ripe pu'er is often described by its multiple layers of aroma: duiwei (堆味) or fermented flavour, cangwei (仓味) or storage flavour, xingwei (腥味) or fish flavour and meiwei (霉味) moldy flavour. The storage locations (Yunnan, Canton or Hong Kong) and storing conditions (wet versus dry storage) will result in distinct flavours. The aromas can be annotated as camphora (樟香), ginseng (参香), jujube (枣香), costus (木香), minty (荷香) or very aged (陈香). Raw pu'er is often distinguished by its floral (花香), grassy (草香), fresh (清香), herbal (药香), fruity (水果), or honey (蜜香) aroma.
Some pu'er are flavour-infused. Sticky rice pu'er (nuomixiang, 糯米香) is infused with leaves of Strobilanthes tonkinensis, native to Mengla, which gives it a young rice flavour. Bamboo-roasted pu'er is encased in bamboo tubes and undergoes a smoking process. Tangerine pu'er (xiaoqinggan, 小青柑) is made with small green tangerines stuffed with tea. Flower-infused pu'er is made in the form of tea balls (龙珠) or tea cakes.
Cultivation
The method of cultivation can have as much of an effect on the final product as region or grade. There are three widely used methods of cultivation for pu'er:
- Plantation bushes (guànmù, 灌木; taídì, 台地): Cultivated tea bushes, from the seeds or cuttings of wild tea trees and planted in relatively low altitudes and flatter terrain. The tea produced from these plants are often considered inferior due to the use of pesticides and chemical fertilizer in cultivation, the lack of pleasant flavors, and the presence of bitterness or astringency.
- "Wild arbor" trees (yěfàng, 野放): Though often conflated with wild tree especially by producers, this method involves trees from older plantations that were cultivated in previous generations that have gone feral due to the lack of care. These trees are said to produce teas of better flavor due to the higher levels of secondary metabolites produced in the tea tree. Additionally, the trees are typically cared for using organic practices, which includes the scheduled pruning of the trees in a manner similar to pollarding. Despite the good quality of their produced teas, "wild arbor" trees are often not as prized as truly wild trees.
- Wild trees (gŭshù, 古树; literally "old tree"): Teas from old wild trees, grown without human intervention, are typically the highest valued pu'er teas. Such teas are valued for having deeper and more complex flavors, often with camphor or "mint" notes, said to be imparted by the many camphor trees that grow in the same environment as the wild tea trees. Young raw pu'er teas produced from the leaf tips of these trees also lack overwhelming astringency and bitterness often attributed to young pu'er. Pu'er made from the distinct but closely related so-called wild species Camellia taliensis can command a much higher price than pu'er made from the more common Camellia sinensis.
Determining whether or not a tea is wild is a challenging task, made more difficult through the inconsistent and unclear terminology and labeling in Chinese. Terms like yěshēng (野生; literally "wild" or "uncultivated"), qiáomù (乔木; literally "tall tree"), yěshēng qiáomù (野生乔木; literally "uncultivated trees"), and gǔshù are found on the labels of cakes of both wild and "wild arbor" variety, and on blended cakes, which contain leaves from tea plants of various cultivations. These inconsistent and often misleading labels can easily confuse uninitiated tea buyers regardless of their grasp of the Chinese language. As well, the lack of specific information about tea leaf sources in the printed wrappers and identifiers that come with the pu'er cake makes identification of the tea a difficult task. Pu'er journals and similar annual guides such as The Profound World of Chi Tse, Pu-erh Yearbook, and Pu-erh Teapot Magazine contain credible sources for leaf information. Tea factories are generally honest about their leaf sources, but someone without access to tea factory or other information is often at the mercy of the middlemen or vendor. Many pu'er aficionados seek out and maintain relationships with vendors who they feel they can trust to help mitigate the issue of finding the "truth" of the leaves.
Even in the best of circumstances, when a journal, factory information, and trustworthy vendor all align to assure a tea's genuinely wild leaf, fakes teas are common and make the issue even more complicated. Because collectors often doubt the reliability of written information, some believe certain physical aspects of the leaf can point to its cultivation. For example, drinkers cite the evidence of a truly wild old tree in a menthol effect ("camphor" in tea specialist terminology) supposedly caused by the Camphor laurel trees that grow amongst wild tea trees in Yunnan's tea forests. As well, the presence of thick veins and sawtooth-edged on the leaves along with camphor flavor elements are taken as signifiers of wild tea.
Grade
Pu'er can be sorted into ten or more grades. Generally, grades are determined by leaf size and quality, with higher numbered grades meaning older/larger, broken, or less tender leaves. Grading is rarely consistent between factories, and first grade tea leaves may not necessarily produce first grade cakes. Different grades have different flavors; many bricks blend several grades chosen to balance flavors and strength.
Season
Harvest season also plays an important role in the flavor of pu'er. Spring tea is the most highly valued, followed by fall tea, and finally summer tea. Only rarely is pu'er produced in winter months, and often this is what is called "early spring" tea, as harvest and production follows the weather pattern rather than strict monthly guidelines.
Regions
Yunnan
Pu'er is produced in almost every county and prefecture in the province. Proper pu'er is sometimes considered to be limited to that produced in Pu'er City.
Six Great Tea Mountains
The best known pu'er areas are the Six Great Tea Mountains (), a group of mountains in the north of Mengla County, Xishuangbanna, Yunnan, renowned for their climates and environments, which not only provide excellent growing conditions for pu'er, but also produce unique taste profiles (akin to terroir in wine) in the produced pu'er tea. Over the course of history, the designated mountains for the tea mountains have either been changed or listed differently.
In the Qing dynasty government records for Pu'er (普洱府志), the oldest historically designated mountains were said to be named after six commemorative items left in the mountains by Zhuge Liang, These mountains are all located northeast of the Lancang River (Mekong) in relatively close proximity to one another. The mountains' names, in the Standard Chinese character pronunciation are:
- Gedeng (革登山)
- Yiwu (易武山)
- Mangzhi (莽枝山) after the '60s the cakes featured a blend of Yunnan and Guangdong máochá, and the most recent production of these cakes contains mostly from the latter.
In late 2008, the Chinese government approved a standard declaring pu'er tea as a "product with geographical indications", which would restrict the naming of tea as pu'er to tea produced within specific regions of Yunnan province. The standard has been disputed, particularly by producers from Guangdong. Fermented tea in the pu'er style made outside of Yunnan is often branded as "dark tea" in light of this standard.
Other regions
In addition to China, border regions touching Yunnan in Vietnam, Laos, and Burma are also known to produce pu'er tea, though little of this makes its way to the Chinese or international markets.
Tea factories
thumb|Pu'er tea from Yunnan, Menghai Tea Factory and Xiaguan Tea Factory
thumb|upright=0.68|A Menghai microprinted ticket, first appearing in 2006
Factories are generally responsible for the production of pu'er teas. While some individuals oversee small-scale production of high-quality tea, the majority of tea on the market is compressed by factories or tea groups. Until recently factories were all state-owned and under the supervision of the China National Native Produce & Animal Byproducts Import & Export Corporation (CNNP), Yunnan Tea Branch. Kunming Tea Factory, Menghai Tea Factory, Pu'er Tea Factory and Xiaguan Tea Factory are the most notable of these state-owned factories. While CNNP still operates today, few factories are state-owned, and CNNP contracts out much production to privately owned factories.
Different tea factories have earned good reputations. Menghai Tea Factory and Xiaguan Tea Factory, which date from the 1940s, have enjoyed good reputations, but in the twenty-first century face competition from many of the newly emerging private factories. For example, Haiwan Tea Factory, founded by former Menghai Factory owner Zhou Bing Liang in 1999, has a good reputation, as do Changtai Tea Group, Mengku Tea Company, and other new tea makers formed in the 1990s. However, due to production inconsistencies and variations in manufacturing techniques, the reputation of a tea company or factory can vary depending on the year or the specific cakes produced during a year.
The producing factory is often the first or second item listed when referencing a pu'er cake, the other being the year of production.
Recipes
Tea factories, particularly formerly government-owned factories, produce many cakes using recipes for tea blends, indicated by a four-digit recipe number. The first two digits of recipe numbers represent the year the recipe was first produced, the third digit represents the grade of leaves used in the recipe, and the last digit represents the factory. The number 7542, for example, would denote a recipe from 1975 using fourth-grade tea leaf made by Menghai Tea Factory (represented by 2).
- Factory numbers (fourth digit in recipe):
- Kunming Tea Factory
- Menghai Tea Factory aka Dayi
- Xiaguan
- Lan Cang Tea Factory or Feng Qing Tea Factory
- Pu-erh Tea Factory (now Pu-erh Tea group Co. Ltd )
- Six Famous Tea Mountain Factory
- unknown / not specified
- Haiwan Tea Factory and Long Sheng Tea Factory
Tea of all shapes can be made by numbered recipe. Not all recipes are numbered, and not all cakes are made by recipe. The term "recipe," it should be added, does not always indicate consistency, as the quality of some recipes change from year-to-year, as do the contents of the cake. Perhaps only the factories producing the recipes really know what makes them consistent enough to label by these numbers.
Occasionally, a three digit code is attached to the recipe number by hyphenation. The first digit of this code represents the year the cake was produced, and the other two numbers indicate the production number within that year. For instance, the seven digit sequence 8653-602, would indicate the second production in 2006 of factory recipe 8653. Some productions of cakes are valued over others because production numbers can indicate if a tea was produced earlier or later in a season/year. This information allows one to be able to single out tea cakes produced using a better batch of máochá.
Tea packaging
Pu'er tea is specially packaged for trade, identification, and storage. These attributes are used by tea drinkers and collectors to determine the authenticity of the pu'er tea.
Individual cakes
upright=1.13|thumb|Typical contents of a wrapped bǐngchá
Pu'er tea cakes, or bǐngchá (饼茶 or 餅茶), are almost always sold with a:
- Wrapper: Made usually from thin cotton cloth or cotton paper and shows the tea company/factory, the year of production, the region/mountain of harvest, the plant type, and the recipe number. The wrapper can also contain decals, logos and artwork. Occasionally, more than one wrapper will be used to wrap a pu'er cake.
- Nèi fēi (内飞 or 內飛): A small ticket originally stuck on the tea cake but now usually embedded into the cake during pressing. It is usually used as proof, or a possible sign, to the authenticity of the tea. Some higher end pu'er cakes have more than one nèi fēi embedded in the cake. The ticket usually indicates the tea factory and brand.
- Nèi piào (内票): A larger description ticket or flyer packaged loose under the wrapper. Both aid in assuring the identity of the cake. It usually indicates factory and brand. As well, many nèi piào contain a summary of the tea factories' history and any additional laudatory statements concerning the tea, from its taste and rarity, to its ability to cure diseases and effect weight loss.
- Bǐng (饼 or 餅): The tea cake itself. Tea cakes or other compressed pu'er can be made up of two or more grades of tea, typically with higher grade leaves on the outside of the cake and lower grades or broken leaves in the center. This is done to improve the appearance of the tea cake and improve its sale. Predicting the grade of tea used on the inside takes some effort and experience in selection. However, the area in and around the dimple of the tea cake can sometimes reveal the quality of the inner leaves.
upright=1.13|thumb|A tǒng of recipe 7742 tea cakes wrapped in bamboo shoot husks
Recently, nèi fēi have become more important in identifying and preventing counterfeits. Menghai Tea Factory in particular has begun microprinting and embossing their tickets in an effort to curb the growth of counterfeit teas found in the marketplace in the late 1990s and early 2000s. Some nèi fēi also include vintage year and are production-specific to help identify the cake and prevent counterfeiting through a surfeit of different brand labels.
Counterfeit pu'er is common. The practices include claiming the tea is older than it actually is, misidentifying the origin of the leaf as Yunnan instead of a non-Yunnan region, labeling terrace tea as forest tea, and selling green tea instead of raw pu'er. The interpretation of the packing of pu'er is usually dependent on the consumer's knowledge and negotiation between the consumer and trader.
Wholesale
When bought in large quantities, pu'er tea is generally sold in stacks, referred to as a tǒng (筒), which are wrapped in bamboo shoot husks, bamboo stem husks, or coarse paper. Some tongs of vintage pu'er will contain a tǒng piào (筒票), or tong ticket, but it is less common to find them in productions past the year 2000. There is an ongoing argument as to whether high fluctuations in humidity negatively impact tea quality.
- Sunlight: Tea that is exposed to sunlight dries out prematurely, and often becomes bitter.
- Temperature: Teas should not be subjected to high heat since undesirable flavors will develop. However at low temperatures, the aging of pu'er tea will slow down drastically. It is argued whether tea quality is adversely affected if it is subjected to highly fluctuating temperature.
When preserved as part of a tong, the material of the tong wrapper, whether it is made of bamboo shoot husks, bamboo leaves, or thick paper, can also affect the quality of the aging process. The packaging methods change the environmental factors and may even contribute to the taste of the tea itself.
Age is not the sole factor in determining pu'er quality. Similar to aging wine, the tea reaches a peak with age and can degrade in quality afterwards. Due to the many recipes and different processing methods used in the production of different batches of pu'er, the optimal age for each tea will vary. Some may take 10 years while others 20 or 30+ years.
Raw pu'er
Over time, raw pu'er acquires an earthy flavor due to slow oxidation and other, possibly microbial processes. However, this oxidation is not analogous to the oxidation that results in green, oolong, or black tea, because the process is not catalyzed by the plant's own enzymes but rather by fungal, bacterial, or autooxidation influences. Pu'er flavors can change dramatically over the course of the aging process, resulting in a brew tasting strongly earthy but clean and smooth, reminiscent of the smell of rich garden soil or an autumn leaf pile, sometimes with roasted or sweet undertones. Because of its ability to age without losing "quality", well aged good pu'er gains value over time in the same way that aged roasted oolong does.
Raw pu'er can undergo "wet storage" (shīcāng, 湿仓) and "dry storage" (gāncāng 干仓), with teas that have undergone the latter ageing more slowly, but thought to show more complexity. Dry storage involves keeping the tea in "comfortable" temperature and humidity, thus allowing the tea to age slowly. Wet or "humid" storage refers to the storage of pu'er tea in humid environments, such as those found naturally in Hong Kong, Guangzhou and, to a lesser extent, Taiwan.
The practice of "Pen Shui" 喷水 involves spraying the tea with water and allowing it dry off in a humid environment. This process speeds up oxidation and microbial conversion, which only loosely mimics the quality of natural dry storage aged pu'er. "Pen Shui" pu'er not only does not acquire the nuances of slow aging, it can also be hazardous to drink because of mold, yeast, and bacteria cultures.
Pu'er properly stored in different environments can develop different tastes at different rates due to environmental differences in ambient humidity, temperature, and odors.
Preparation
Preparation of pu'er involves first separating a 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.
See also
- List of Chinese teas