Aging and storage of Pu'er

Pu’er teas of all varieties, shapes, and cultivation can be aged to improve their flavour, but the tea's physical properties will affect the speed of aging as well as its quality. These properties include:

·    ·  Leaf quality: The most important factor, arguably, is leaf quality. Maocha that has been improperly processed will not age to the level of finesse as properly processed maocha. The grade and cultivation of the leaf also greatly affect its quality, and thus its aging.

·    ·  Compression: The tighter a tea is compressed, the slower it will age. In this respect, looser hand- and stone-pressed Pu’ers will age more quickly than denser hydraulic-pressed Pu’er.

·    ·  Shape and size : The more surface area, the faster the tea will age. Bingcha and zhuancha thus age more quickly than golden melon, tuocha, or jincha. Larger bingcha age slower than smaller bingcha, and so forth.

Just as important and the tea's properties, environmental factors for the tea's storage also affect how quickly and successfully a tea ages. They include:

·    ·  Air flow: Regulates the oxygen content surrounding the tea and removes odours from the aging tea. Dank, stagnant air will lead to dank, stale smelling aged tea. Wrapping a tea in plastic will eventually arrest the aging process.

·    ·  Odours: Tea stored in the presence of strong odours will acquire them, sometimes for the duration of their "lifetime." Airing out Pu’er teas can reduce these odours, though often not completely.

·    ·  Humidity : The higher the humidity, the faster the tea will age. Liquid water accumulating on tea may accelerate the aging process but can also cause the growth of mold or make the flavour of the tea less desirable. 60-85% humidity is recommended. 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’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.

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.

 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 being much more desirable. Dry storage involves keeping the tea in "comfortable" temperature and humidity, thus allowing the aging process to occur slowly. Wet storage 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. Wet storage 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 odours.

 For instance, similar batches of Pu’er stored in the different environments of Taiwan and Hong Kong are known to age very differently. Because the process of aging Pu’er is a lengthy one and teas may change owners several times, a batch of Pu’er may undergo different aging conditions, even swapping wet and dry storage conditions, which can drastically alter the flavor of that tea. Raw Pu’er should not be stored at very high temperatures, or be exposed to direct contact with sunlight, heavy air flow, liquid water, or unpleasant smells, since such poor storage conditions can ruin even the best quality Pu’er.

Although low to moderate air flow is important for producing a good quality aged raw Pu’er, it is generally agreed by most collectors and connoisseurs that raw Pu’er tea cakes older than 30 years old should not be further exposed to "open" air since it would result in the loss of flavours or degradation in mouthfeel. The tea should instead be preserved by wrapping or hermetically sealing it in plastic wrapping or ideally glass.

Ripened Pu’er

Since the ripening process was developed to imitate aged raw Pu’er, many arguments surround the idea of whether aging ripened Pu’er is desirable. Mostly, the issue rests on whether aging ripened Pu’er will, better or worse, alter the flavor of the tea.

It is often recommended to age ripened Pu’er to "air out" the unpleasant musty flavours and odours formed due to maocha fermentation. However, some collectors argue that keeping ripened Pu’er 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’er indeed does take on nuances through aging, and point to side-by-side taste comparisons of ripened Pu’er of different ages. Though the storing period increases the value of the tea, it is not often that such actions will be taken as it is not economically efficient.