It is a well-known fact that tea should be drunk fresh, and lovers of the drink insist on respecting this. However shops selling tea often display huge caddies on the shelves, brimming with tea but with no indication of the season, or even the year, inwhich it was harvested.
Although an exception can, to some extent, be made in the case of black tea, which has undergone oxidation during the production process and therefore lasts longer, the same does not apply to green tea. This type of tea is usually consumed in the year of production, and all possible means are used to impede the inevitable ageing process which makes it stale.
Green tea is the most widely consumed type of tea in Japan, Korea and most of China, and the difference between “old” and “new” teas is just as important now as it was in the past. In trade, the arrival of “new” tea on the market marks the depreciation of the previous year’s tea.
However there are exceptions to every rule and tea is a commodity that comes in many different types and forms. In fact, with regard to the recognised precept that freshness equals quality, there are those who state the opposite. Let’s take a look at Hong Kong, the “perfumed port” on the south China sea, and important centre of eastern Asian trade.
Hong Kong is definitely not known for tea production, but a great deal of it is drunk there. Apart from the widely used jasmine tea, favourite varieties of tea in the ex-British colony include the excellent wulong (oolong) and white teas grown in the neighbouring Guangdong province, and in the province of Fujian. But Hong Kong residents have become especially fond of a type of tea grown in the far-off province of Yunnan – Pu’er tea. This type of tea astonishes everyone who tries it, including the Chinese, because its colour, aroma and flavour are definitely “old”.
The term Pu’er (P’ou-lei in Cantonese) denotes a large family of teas including loose leaf varieties and (more typically) those compressed into bricks or cakes. The leaves are picked from large-leaved tea plants growing on the uplands of Simao and Xishuang Banna in the south of Yunnan, on the border with Laos and Burma. This is believed to be the area where the tea plant first originated and many ancient, tall tea trees still grow there (the oldest is estimated to be 1700 years old).
The Pu’er production process is initially the same as that of green tea, including fixation (treatment at high temperatures), rolling and sun drying. The semi-processed product is then steamed and shaped in moulds, and air-dried. The cakes vary greatly in size and shape, from square or rectangular bricks to round flat loaves, from the small bowl-shaped Tuocha (weighing only a few grams) to huge masses of compressed tea weighing dozens of kilograms, shaped like a pumpkin or tree-trunk.
Although it is something of a rarity today, compressed tea used to be the most commonly-used form in ancient China. As drinking loose leaf tea became more popular, cakes of compressed tea were still made in the south west of the country, almost exclusively for trade with Mongolia, Tibet and other nations on the borders of the empire. Pu’er tea was also drunk China itself, due to its recognised medicinal properties. Traditional pharmacopoeias attribute eupeptic properties to this type of tea (aiding digestion and relieving stomach trouble) as well as claiming it can loosen catarrh, favour circulation of bodily fluids and help with a hangover from over-indulgence in alcohol. Modern medicine also adds the properties of removing fat and reducing cholesterol.
The long journey that took the convoys from Pu’er to their various destinations, the warm, damp climates caused the cakes of tea to undergo a natural transformation which may have been the original cause of its now-typical “aged” flavour, and the functional maturing process now adopted to obtain the same flavour.
During ageing (known as post-fermentation, as distinct from the fermentation undergone by fresh leaves in the production process of black and wulong tea) – resulting from the oxidation and fermentation processes – the original green colour of the tea changes to a dark greyish brown, and the drink itself is a deep, hazy dark brown in colour. Green tea grassy fragrance give way to complex, mature aromas with hints of musk and earth, while the rough, bitter and astringent flavour typical of fresh Pu’er tea leaves is mellowed and becomes sweeter and more full-bodied. Chinese medicine claims that tea removes heat from the body, while ageing actually reduces its cooling properties and it is therefore especially suited to elderly people and those with a delicate stomach. “The older the better” would certainly seem to hold good in this case.
Pu’er tea is traditionally matured in a dry, airy place for several years. According to the guidelines it should be aged for at least twenty years, and only tea aged for over forty years would merit the title of an “exceptional” product. Unfortunately such long ageing periods do not meet the demands of the market, and therefore an artificial ageing technique has been invented to obtain tea with the aroma and flavour characteristics described above, in a much shorter time. The technique consists of wetting the cakes of fresh tea and leaving them in a closed room at a high temperature in order to accelerate the fermentation process. The final result is not necessarily inferior to that of natural ageing: at the end of the treatment the tea loses its astringent flavours and becomes sweet and mellow, and the aromas become appreciably “old”, although they may sometimes be excessively musty or mouldy.
Pu’er purists say that the main difference between “raw” (untreated) cakes of tea, which have been naturally aged, and those “ripened” artificially consists in the differing disposition to flavour development over time. The flavour of untreated tea becomes sweeter and fuller as the years pass and continues to change with natural ageing. Artificially aged teas are ready to drink but only develop to a certain extent, after which further maturing serves no useful purpose.
In Hong Kong Pu’er tea is mainly consumed in restaurants specialising in the preparation of dimsum and other Cantonese delicacies, and low quality, artificially aged tea is usually used, often blended with sweet white chrysanthemum flowers from Hangzhou. Higher quality tea that has been aged naturally is available in many specialised shops or in the Tea Art Houses. Here you often see large quantities of cakes of Pu’er tea, wrapped in their original bamboo leaf packaging, left for years to improve while they gather dust on the shelves.
This particular passion for Pu’er in Hong Kong has spread to tea lovers in Taiwan and other countries in the region. It is curious to note that the mania for ageing Pu’er in the typical way is now extending to other varieties. Tea houses and tea lovers are becoming more interested in aged “rock” teas (yancha) from the Wuyi mountains, such as Dahongpao and Shiuxian. These deep toasted wulong teas are made in the province of Fujian and their original strong and pungent character seems to be softened and improved by a few years’ ageing.
Livio Zanini, sinologist and tea connoisseur, honorary director of China International Tea Culture Institute. He teaches Chinese translation at Ca’ Foscari University, Venice
Photo: a tea shop in Canton (L. Zanini)