''Pu-erh'' tea can be purchased as either ''raw/green'' or ''ripened/cooked'' , 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 variant 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'' .
Introduction and history
''Pu-erh tea'' is traditionally made with leaves from old wild tea trees of a variety known as "broad leaf tea" or ''Camellia sinensis var. assamica'', which is found in southwest China as well as the bordering tropical regions in Burma, Vietnam, Laos, and the very eastern parts of India. The shoots and young leaves from this varietal are often covered with fine hairs, with the pekoe larger than other tea varietals. The leaves are also slightly different in chemical composition, which alter the taste and smell of the brewed tea, as well as its desirability for aging. Due to the scarcity of old wild tea trees, ''pu-erh'' made using such trees blended from different tea mountains of Yunnan are highly valued, while more and more connoisseurs are seeking ''pu-erh'' with leaves taken from a single tea mountain's wild forests. The history of ''pu-erh'' tea can be traced back to the Eastern Han Dynasty.
''Pu-erh'' is well known for the fact that it is a compressed tea and also that it typically ages well to produce a pleasant drink. Through storage, the tea typically takes on a darker colour and mellower flavour characteristics. Often ''pu-erh'' leaves are compressed into tea cakes or bricks, and are wrapped in various materials, which when stored away from excessive moisture, heat, and sunlight help to mature the tea. Pressing of ''pu-erh'' into cakes and aging the tea cakes possibly originated from the natural aging process that happened in the storerooms of tea drinkers and merchants, as well as on horseback caravans on the Ancient tea route that was used in ancient Yunnan to trade tea to Tibet and more northern parts of China. Compression of the tea into dense bulky objects likely eased horseback transport and reduced damage to the tea.
All types of ''pu-erh'' tea are created from máochá（), a mostly un green tea processed from a "large leaf" variety of ''Camellia sinensis'' found in the mountains of southern Yunnan. ''Maocha'' can undergo "ripening" for several months prior to being compressed to produce ripened pu-erh , or be directly compressed to produce raw pu-erh.
While unaged and unprocessed ''raw pu-erh'' is technically a type of green tea, ''ripened'' or ''aged raw pu-erh'' has occasionally been mistakenly categorised as a subcategory of black tea due to the dark red colour of its leaves and liquor. However, ''pu-erh'' in both its ripened or aged forms has undergone secondary oxidization and caused both by organisms growing in the tea as well as from free-radical oxidation, thus making it a unique type of tea.
In China, where fully-oxidised tea is known as "red tea," ''pu-erh'' is indeed classified as a "black tea" , something which is resented by some who argue for a separate category for ''pu-erh'' as most other black teas tend to be of low standard and status.
Raw ''pu-erh'' and ''Máochá''
After picking appropriate tender leaves, the first step in making raw or ripened ''pu-erh'' is converting the leaf to ''máochá'' . Plucked leaves are handled gingerly to prevent bruising and unwanted oxidation. Weather permitting, the leaves are then spread out in the sun or a ventilated space to wilt and remove some of the water content. 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-erh''. The wilting process may be skipped altogether depending on the tea processor.
The leaves are then dry pan-fried using a large wok in a process called "kill green" , which arrests enzyme activity in the leaf and prevents further oxidation. With enzymatic oxidation halted, the leaves can then be rolled, rubbed, and shaped through several steps into strands. The shaped leaves are then ideally dried in the sun and then manually picked through to remove bad leaves. Sometimes maocha is aged uncompressed and sold at its maturity as aged loose-leaf raw ''pu-erh''.
''Raw pu-erh tea'' , also known as "''uncooked pu-erh''" or "''green pu-erh''," is simply ''máochá'' tea leaves that have been compressed into its final form without additional processing.
Ripened ''pu-erh'' tea is pressed ''maocha'' that has been specially processed to imitate aged raw ''pu-erh''. Although it is more commonly known as "''cooked pu-erh''," the process does not actually employ cooking to imitate the aging process. The term may come about due to inaccurate transliteration due to the dual meaning of "shoú" as both "''fully cooked''" and "''fully ripened''" .
The process used to convert ''máochá'' into ripened ''pu-erh'' is a recent invention that 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 ''wòdūi'' , which involves piling, dampening, and turning the tea leaves in a manner much akin to composting.
The piling, wetting, and mixing of the piled ''máochá'' ensures even fermentation. Poor control in fermentation/oxidation process can result in bad ripened ''pu-erh'', characterized by badly decomposed leaves and an aroma and texture reminiscent of compost. The ripening process typically takes anywhere from half a year to one year after it has begun. As such, a ripened ''pu-erh'' produced in early 2004 will be pressed in the winter of 2004/2005, and appear on the market between late 2005 or early 2006.
This process was first developed in 1972 by Menghai Tea Factory and Kunming Tea Factory to imitate the flavor and color of aged raw ''pu-erh''. This technique was an adaptation of "wet storage" techniques that were being used by merchants to falsify the age of their teas. Mass production of ripened ''pu-erh'' began in 1975. It can be consumed without further aging, though it can also be stored to "air out" some of the less savory flavors and aromas acquired during fermentation. The tea is often compressed but is also common in loose form. Some collectors of ''pu-erh'' believe that ripened ''pu-erh'' should not be aged for more than a decade.
To produce ''pu-erh'' many additional steps are needed prior to the actual pressing of the tea. First, a specific quantity of dry ''máochá'' or ripened tea leaves pertaining to the final weight of the bingcha is weighed out. The dry tea is then lightly steamed in perforated cans to soften and make it more tacky. This will allow it to hold together and not crumble during compression. A ticket, called a "''Nèi fēi''" or additional adornments, such as coloured ribbons, are placed on or in the midst of the leaves and inverted into a cloth bag or wrapped in cloth. The pouch of tea is gathered inside the cloth bag and wrung into a ball, with the extra cloth tied or coiled around itself. This coil or knot is what produces the dimpled indentation at the reverse side of a tea cake when pressed. Depending on the shape of ''pu-erh'' being produced, a cotton bag may or may not be used. For instance, ''brick'' or ''square'' teas often are not compressed using bags.
Depending on the desired product and speed, from quickest and tightest to slowest and loosest, pressing can either be done by:
* A ''hydraulic press'', which forces the tea into a metal form that is occasionally decorated with a motif in sunken-relief. Due to its efficiency, this method is commonly used to make all forms of pressed ''pu-erh''. Tea can be pressed in the press either with or without it being bagged, with the latter done by utilizing a metal mould. Tightly compressed bing, formed directly into a mould without bags using this method are known as ''tié bǐng'' due to its density and hardness. It is believed that the taste of densely compressed raw ''pu-erh''s can benefit from careful aging for up to several decades.
* A ''lever press'', which was operated by hand for tight pressings and has largely been replaced by the modern hydraulic press.
* A ''large heavy stone'', carved into the shape of a short cylinder with a handle, simply weighs a bag of tea down onto a wooden board. The tension from the bag and the weight of the stone together gives the tea its rounded and sometimes non-uniformed edge. Due to the manual labour involved, this method of pressing is often referred to as: "''Hand''" or "''Stone-pressing''," and is how many artisanal ''pu-erh bing'' are still manufactured.
Pressed ''pu-erh'' is removed from the cloth bag and placed on latticed shelves where they are allowed to air dry, which depending on the wetness of the pressed cakes may take several weeks or months. In ancient times, ''tuocha'' cakes may have had holes punched through the center so that they could be tied together on a rope for easy transport.
| A thick rectangular block of tea, usually in 100g, 250g, 500g, and 1000g sizes. ''Zhuancha'' bricks are the traditional shape that was used for ease of transport along the Ancient tea route by horse caravans.
| A flat square of tea, usually in 100g or 200g sizes. They often contain words that are pressed into the square.
| Literally meaning "tight tea," the tea is shaped much like ''túocha'', but with a stem rather than a convex hollow. This makes them quite similar in form to a mushroom. Pu-erh tea of this shape is generally produced for Tibetan consumption, and is usually 250g or 300g.
| ''Melon, or Gold melon''
| A shape similar to ''tuóchá'', but larger in size with a much thicker body that is decorated with pumpkin-like "stripes". This shape was created for the famous "Tribute tea" that was made expressly for the Qing Dynasty from the best tea leaves of Yiwu Mountain. Larger specimens of this shape are sometimes called "Human-head tea" due in part to its size and shape, as well as the fact that in the past it was often presented in court in a similar manner to severed heads.
Process and oxidation
Although ''pu-erh'' teas are often collectively classified in Western and East Asian tea markets as ''post-fermentation'' or ''black'' teas, respectively, ''pu-erh'' teas in actuality can be placed in three types of processing methods, namely: ''green tea'', ''fermented tea'', and ''secondary-oxidation/fermentation tea''.
''Pu-erh'' can be green teas if they are lightly processed before being pressed into cakes. Such ''pu-erh'' is referred to as ''maocha'' if unpressed and as "green/raw ''pu-erh''" if pressed. While not always palatable, they are relatively cheap and are known to age well for up to 20 or 30 years. ''Pu-erh'' can also be a fermented tea if it undergoes slow processing with fermenting microbes for up to a year. This ''pu-erh'' is referred to as "ripened/cooked ''pu-erh''", and has a mellow flavour and is readily drinkable. Aged ''pu-erh''s are secondary-oxidation and post-fermentation teas. If aged from green ''pu-erh'', the aged tea will be mellow in taste but still clean in flavour.
According to the production process, four main types of ''pu-erh'' are commonly available on the market:
*''Maocha'': Green ''pu-erh'' leaves that are sold in loose form. The raw material for making pressed ''pu-erh''s. Badly processed maocha will result in an inferior pu-erh.
*''Green/raw pu-erh'': Pressed ''maocha'' that has not undergone additional processing. Quality green ''pu-erh'' is highly sought by collectors.
*''Ripened/cooked pu-erh'': Pressed ''maocha'' that has undergone fermentation in the ripening process for up to a year. Badly fermented maocha will create a muddy tea with fishy and sour flavours indicative of inferior aged pu-erhs.
*''Aged raw pu-erh'': A tea that has undergone a slow secondary oxidation and a certain degree of microbial fermentation. Although all types of ''pu-erh'' can be aged, it is typically the pressed raw ''pu-erh''s that are most highly regarded, since aged ''maocha'' and ripened ''pu-erh'' both lack a "clean" and "assertive" taste.
Yunnan province produces the vast majority of ''pu-erh'' tea. Indeed, the province is the source of the tea's name, Pu'er Hani and Yi Autonomous County. ''Pu-erh'' is produced in almost every county and prefecture in the province, but the most famous ''pu-erh'' areas are known as the Six Famous Tea Mountains
Six famous tea mountains
The six famous tea mountains are a group of mountains in Xishuangbanna that are renowned for their climates and environments, which not only provide excellent growing conditions for ''pu-erh'', but also produce unique taste profiles in the produced ''pu-erh'' 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-erh , the oldest historically designated mountains were said to be named after six commemorative items that were left in the mountains by Zhuge Liang, These mountains are all located northeast of the Lancang River in relatively close proximity to one another. The mountains' names, in the Standard Mandarin character pronunciation are:
#''Gedeng'' : The term for "leather stirrup"
#''Mansa'' : The term for "seed sowing bag"
#''Mangzhi'' : The term for "copper cauldron"
#''Manzhuan'' : The term for iron brick"
#''Yibang'': The term for "wooden clapper"
#''Yōulè'' : The term meaning "copper gong"
Southwest of the river there are also six famous tea mountains that are lesser known from due to their isolation by the river.
In addition to China, border regions touching Yunnan in Vietnam, Laos, and Burma are also known to produce ''pu-erh'' tea, though little of this makes its way to the Chinese or international markets.
Perhaps equally or even more important than region or even grade in classifying ''pu-erh'' is the method of cultivation. ''Pu-erh'' tea can come from three different cultivation methods:
*''Plantation bushes'' : 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 considered inferior due to the used of pesticides and in cultivation, and the lack of pleasant flavours, and the presence of harsh bitterness and astringency from the tea.
*''"Wild arbor" trees'': Most producers claim that their ''pu-erh'' is from wild trees, but most use leaves from older plantations that were cultivated in previous generations that have gone feral due to the lack of care. These trees produce teas of better flavour due to the higher levels of secondary metabolite produced in the tea tree. As well, 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 not as prized as the truly wild trees.
*''Wild trees'' : Teas from old wild trees, grown without human intervention, are the highest valued ''pu-erh'' 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-erh'' teas produced from the leaf tips of these trees also lack overwhelming astringency and bitterness often attributed to young ''pu-erh''.
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'' , ''qiáomù'' , ''yěshēng qiáomù'' , 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-erh'' cake makes identification of the tea a difficult task. ''Pu-erh'' 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 an unscrupulous vendor. Many ''pu-erh'' 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.
Sadly, 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 fill the market 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 supposedly caused by the 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 and taken as signifiers of wild tea.
''Pu-erh'' 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, and many bricks feature a blend of several grades chosen to balance flavors and strength.
Harvest season also plays an important role in the flavor of ''pu-erh''. Spring tea is the most highly valued, followed by fall tea, and finally summer tea. Only rarely is ''pu-erh'' 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.
Factories are generally responsible for the production of ''pu-erh'' teas. While some individuals oversee smaller higher-end productions, such as the Xizihao and Yanqinghao brands, enjoys a good reputation, as does 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-erh'' cake, the other being the year of production.
In past two years, a new generation of pu-erh tea factories has been established. For example,ChenSheng Tea Factory ,which is the only one manufacturer to supply the pest Puer tea that called LaoBanZhang ;and YPT Puerh Tea Factory, , already applies the most advanced technology to standardize its product and brands its product with Chinese ancient culture for marketing. High quality mass production and modern have transformed pu-erh tea from a regional traditional Chinese drink to a nationally widespread trend.
Tea factories, particularly formerly government-owned factories, produce many cakes by recipe, indicated by a ''recipe number''. Recipe numbers consists of four-digits. The first two digits represent the year the recipe was first produced, the third digit the grade of leaves used in the recipe, and the last digit represents the factory. 7542, for example, would be a recipe from 19''75'' using ''fourth''-grade tea leaf made by Menghai Tea Factory . There are also those who believe that the third number indicates a recipe for a particular production year. or Feng Qing Tea Factory It is argued whether tea quality is adversely affected if it is subjected to highly fluctuating humidity levels.
* ''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 flavours will develop. However at low temperatures, the aging of ''pu-erh'' 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.
Further to what has been mentioned it should be stressed that a good well-aged Puerh tea is not evaluated by its age alone. Like all things in life, there will come a time when a Puerh teacake reaches its peak before stumbling into a decline. Due to the many recipes and different processing method used in the production of different batches of Puerh, the optimal age for each age will vary. Some may take 10 years while others 20 or 30+ years. It is important to check the status of ageing for your teacakes to know when they peaked so that proper care can be given to halt the ageing process.
Over time, raw ''pu-erh'' 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-erh'' 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-erh'' gains value over time in the same way that aged roasted oolong does.
Raw ''pu-erh'' can undergo "wet storage" and "dry storage" , with teas that have undergone the latter being much more desirable.
''Pu-erh'' properly stored in different environments can develop different tastes at different rates due to environmental differences in ambient humidity, temperature, and odours.
Since the ripening process was developed to imitate aged raw ''pu-erh'', many arguments surround the idea of whether aging ripened ''pu-erh'' is desirable. Mostly, the issue rests on whether aging ripened ''pu-erh'' will, better or worse, alter the flavor of the tea.
It is often recommended to age ripened ''pu-erh'' to "air out" the unpleasant musty flavours and odours formed due to maocha fermentation. However, some collectors argue that keeping ripened ''pu-erh'' longer than 10 to 15 years makes little sense, stating that the tea will not develop further and possibly lose its desirable flavours. Others note that their experience has taught them that ripened ''pu-erh'' indeed does take on nuances through aging,
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''.
Quality of the tea can be determined through inspecting the dried leaves, the tea liquor, or the spent tea leaves. The "true" quality of a specific batch of ''pu-erh'' can ultimately only be revealed when the tea is brewed and tasted. Although, not concrete and sometimes dependent on preference, there are several general indicators of quality:
* ''Dried tea'': There should be a lack of twigs, extraneous matter and white or dark mold spots on the surface of the compressed ''pu-erh''. The leaves should ideally be whole, visually distinct, and not appear muddy. The leaves may be dry and fragile, but not powdery. Good tea should be quite fragrant, even when dry. Good pressed pu-erh often have a matte sheen on the surface of the cake, though this is not necessarily a sole indicator of quality
* ''Liquor'': The tea liquor of both raw and ripe ''pu-erh'' should never appear cloudy. Well-aged raw ''pu-erh'' and well-crafted ripe ''pu-erh'' tea may produce a dark reddish liquor, reminiscent of a dried jujube, but in either case the liquor should not be opaque, "muddy," or black in colour. The flavours of ''pu-erh'' liquors should persist and be revealed throughout separate or subsequent infusions, and never abruptly disappear, since this could be the sign of added flavorants.
**''Young raw puerh'':The ideal liquors should be aromatic with a light but distinct odours of camphor, rich herbal notes like , fragrance floral notes, hints of dried fruit aromas such as preserved plums, and should exhibit only some grassy notes to the likes of fresh sencha. Young raw ''pu-erh'' may sometimes be quite bitter and astringent, but should also exhibit a pleasant mouthfeel and "sweet" aftertaste, referred to as ''gān'' and ''húigān''.
**''Aged raw puerh'': Aged pu-erh should never smell moldy, musty, or strongly fungal, though some ''pu-erh'' drinkers considers these smells to be unoffensive or even enjoyable. The smell of aged pu-erh may vary, with an "aged" but not "stuffy" odour. The taste of aged raw ''pu-erh'' or ripe ''pu-erh'' should be smooth, with slight hints of bitterness, and lack a biting astringency or any off-sour tastes. The element of taste is an important indicator of aged pu-erh quality, the texture should be rich and thick and should have very distinct ''gān'' and ''húigān'' on the tongue and cheeks, which together induces salivation and leaves a "feeling" in the back of the throat.
* ''Spent tea'': Whole leaves and leave bud systems should be easily seen and picked out of the wet spent tea, with a limited amount of broken fragments. Twigs, and the fruits of the tea plant should not be found in the spent tea leaves, however animal hair, strings, rice grains and chaff may occasionally be included in the tea. The leaves should not crumble when rubbed, and with ripened ''pu-erh'', it should not resemble compost. Aged raw puerh should have leaves that unfurl when brewed while leaves of most ripened puerh will generally remain closed.
In culture, ''pu-erh'' is known as ''po-lay'' tea. Among the Cantonese long settled in California, it is called ''bo-nay'' or ''po-nay'' tea. It is often drunk during dim sum meals, as it is believed to help with digestion. It is not uncommon to add dried osmanthus flowers, pomelo rinds, or chrysanthemum flowers into brewing ''pu-erh'' tea in order to add a light, fresh fragrance to the tea liquor. ''Pu-erh'' with chrysanthemum is the most common pairing, and referred as ''guk pou'' or ''guk bou'' . ''Pu-erh'' is considered to have some medicinal qualities.
Drinking pu-erh tea is purported to aid in digestion, reduce blood cholesterol and lipid levels. It is also widely believed in Chinese cultures to counteract the unpleasant effects of heavy alcohol consumption. In traditional Chinese medicine, the tea is believed to invigorate the spleen and inhibit "dampness." In the stomach, it is believed to reduce heat and "descends qi".
Some ''pu-erh'' brick tea has been found to contain very high levels of fluorine, because it is generally made from lesser quality older tea leaves and stems, which accumlulate fluorine. Its consumption has led to fluorosis in areas of high brick tea consumption, such as Tibet.
Pu-erh tea can generally improve in taste over time . Teas that can be aged finely are typically:
#Made from high quality material
#Stored properly over the years
The common misconception is that all types of pu-erh tea will improve in taste -- and therefore get more valuable as an investment item -- as they get older. There are many requisite variables for a pu-erh tea to age beautifully. Further, the cooked pu-erh will not evolve as dramatically as the raw type will over time from the secondary oxidation and fermentation.
As in wine, only the finely made and properly stored ones will improve and increase in value. And as in wine, the percentage of those that will improve over a long period of time is only a small fraction of what is available in the market today.