This article is intended to act as a somewhat brief (though it's still pretty long) introduction to one of the most mysterious, ancient, complex and collectible tea genres--Pu-erh, the compressed tea cakes or bricks that have potential to improve with age. Although it is gradually becoming known in the West, this enigmatic tea genre is still subject to a lot of misunderstanding and misinformation. Hopefully, this entry will clear up some potential questions about pu-erh and provide you with enough general knowledge and tools to begin exploring pu-erh from an informed perspective.
In terms of processing, pu-erh (pronounced "poo-air," or "poo-er") is a living fossil--the practice of compressing teas into bricks or cakes was widespread and industry-standard hundreds of years ago, but today, in terms of popularity, it has been replaced by tea in loose form. Pu-erh tea is named for a county in the Yunnan province of China; Yunnan is generally regarded as the primary source for best pu-erh tea leaves because the province's high mountains receive more sunlight than most areas of China, making for ideal strong, large leaves. The "traditional" pu-erh processing methods that today's production emulates were threatened during the Cultural Revolution of the late 1960's and 1970's--during this time, much of the country's stock of antique pu-erh was destroyed. Since then, pu-erh from the 50's and 60's has become especially rare (and extremely expensive), and the techniques used to produce it have been pursued by modern pu-erh producers who hope to recapture the tea's past glory. Today, pu-erh production is split between teas produced by plantations and teas sourced from semi-wild, old-growth, overgrown ancient tea plantations on difficult-to-access mountains. Since the late 20th century, pu-erh has seen an explosive increase in interest both in China and abroad, resulting in rapid price inflation of aged pu-erh, new pu-erh, and the highest quality tea leaves used to produce pu-erh.
What separates pu-erh from the other tea types is its processing--it's not important which tea plant cultivar produces the leaves. Depending on how the teas are processed, the result will either produce sheng (or raw, uncooked, or green) pu-erh, or shu (ripened, cooked or black) pu-erh. Regardless of the end result, the first ingredient is mao cha--"rough tea"--the loose leaves that will eventually be compressed into sheng or shu pu-erh.
Mao Cha (pictured left, click to enlarge; thanks to Guang at http://www.houdeasianart.com for these pictures) consists of buds, tender leaves, stems, and whole semi-mature leaves. In general, a good mix of these elements produces good pu-erh (i.e. not ALL buds or ALL mature leaves). The processing is outwardly simple, but the finer points of making mao cha are touchy and require fine skills and experience. After plucking, the tea leaves are briefly wilted on bamboo mats to slightly reduce moisture content. Next, the leaves go through the "killing green" process, during which the leaves are pan-fired, de-enzyming the leaves and preventing any oxidization or fermentation. The killing green process is extremely important--the liquor of pu-erh teas that have not undergone correct or complete killing green is often cloudy or murky, and it denotes low quality craftsmanship. After killing green, the leaves are carefully bruised to release flavor without breaking leaves or buds, then dried in the open air or by the sun to the ideal low-moisture (bud not brittle) content. From this point, the mao cha is transported to either large or small factories to become sheng or shu pu-erh. We'll start with shu.
Shu, or ripened pu-erh (pictured right), was invented mid-20th century in an effort to approximate the flavors and character of aged sheng pu-erh, without the years of aging and usual high price commanded by aged sheng pu-erh. This effect is achieved through a rigorously-controlled process involving moisture and heat. The loose mao cha is moistened with water and stacked into piles. In these conditions (similar to skilled compost production), the wet leaves increase in temperature by themselves (autothermally), which quickly increases the rate of post-fermentation (since the leaves are being fermented after the initial killing green process), simulating the process of aging. Of course, the process is delicate and the piles must be turned and monitored to ensure that the leaves don't get too hot and that moisture and oxidation levels are equivalent. Since this precisely-controlled process includes increased temperature, shu pu-erh is often referred to as "cooked," but this term is inaccurate because no cooking actually takes place. Finally, the post-fermented leaves are compressed into different shapes--usually disc-shaped cakes (called "bing cha" or "beeng cha"), but also often large and small bird's nest-shaped forms (tuo cha). Shu pu-erh processing recipes differ from factory to factory, so it is likely that flavor and quality standards will be well-controlled or recognizable for a particular factory.
Like any tea, there are premium grades of shu pu-erh and there are types that are extremely low-grade. For many Westerners, "pu-erh" refers to very low-grade shu pu-erh (often served at dim sum restaurants) that tastes extremely earthy--often to the point of tasting like dirt. In reality, high quality shu pu-erh can make for a very refined tea experience--it's usually incredibly smooth, rich, and abounding in flavors that can range between earthy, spicy, woody, mushroomy and chocolaty. Like sheng pu-erh, shu pu-erh's flavor can be improved with aging, but to a lesser extent (see below for aging-related information). Regardless of its quality, though, shu pu-erh is generally regarded as subordinate in quality to aged premium sheng pu-erh, which is unparalleled for its complexity and reputation. Aged sheng pu-erh is rare, expensive, and sometimes difficult to verify as authentic, though, and shu pu-erh potentially offers a similar high-quality experience at a fraction of the cost and time commitment.
The undisputed king of the pu-erh world, sheng pu-erh's processing is less mysterious but no less delicate than that of shu pu-erh. For sheng pu-erh (pictured left), the finished mao cha is weighed and re-hydrated using steam. This step often separates high-quality sheng pu-erh from mid-grade; if the source of the steam isn't pure, the tea leaves will acquire a smoky flavor and character. Although smokiness doesn't mean a pu-erh is inferior (light smokiness will diminish with a few years of aging), the absence of smokiness in young sheng pu-erh is a hallmark of quality production and attention to detail. After rehydration, the more moisturized mao cha is placed in a cotton bag and gently formed into a ball. The ball/bag is then compressed using either a large, cylindrical stone (traditional) or via a special press (modern). Both methods produce top-grade pu-erh, though stone molding generally compresses the tea slightly less, which is better for aging. The mao cha can also be pressed into other shapes, including rectangular or square bricks, birds nest (tuo cha, pictured right top), mushroom (jing cha, pictured right bottom), or even giant melons. After compression, the cakes are sun-dried, wrapped in paper, and sun dried again before being packaged for sale. Bing cha are traditionally sold by the tong, a bamboo or banana leaf-wrapped stack of 7 cakes. Bing cha usually weigh between 350 grams and 400 grams, with 357 grams being an industry standard. When packaged, each pu-erh cake will have a Nei Fei (an embedded inner ticket) and a Nei Piao (an inner ticket) which provide more information about the tea cake's production, the factory, and the quality of the product. The dimensions and appearance of these items are especially important in aged pu-erh, since forgery is common and careful inspection of the tickets can verify a pu-erh's authenticity.
The flavor of recently-produced sheng pu-erh can vary widely--depending on how the leaves were steamed during re-hydration, and especially on they type of mao cha used to produce the pu-erh, the flavor can vary widely to encompass floral notes, fruitiness, woodiness, flavors similar to green tea, honey-like sweetness, and many other elements. Most young pu-erhs possess a distinct bitterness; some people find pu-erh's bitterness to be too strong, or overpowering, but it should be noted that it's not the same type of bitterness as, say, an oversteeped green tea. Bitterness in high quality young pu-erh should transform during swallowing or in the aftertaste, taking on sweeter and more complex notes. As the pu-erh ages, its bitterness will decrease, and bitterness in young pu-erh is by no means a sign of inferiority.
Be they produced by large, state-run companies or private producers, all pu-erhs are produced in some sort of factory. Menghai (also the name of a county in Yunnan) is by far the most popular pu-erh factory in China; it is unmatched in its brand name recognition and standard of quality. Factories like Menghai often produce teas every year based on a specific "recipe." In Menghai's case, each recipe has a number--for example, Menghai's 7542 recipe is an industry standard for quality and age-ability--the first two digits in the recipe stand for the year that the recipe was created (1975) and the second two digits (usually tougher to decode) refer to the types of leaves and quality used in the blend. In essence, a recipe is the percentage of each cake that comes from a given leaf type--buds, large leaves, small leaves, stems, and quality of each type are all factors. Therefore, a given recipe can be reproduced year after year with similar results (although, of course, harvest quality and climate conditions can affect a given year's harvest). In recent years, a number of pu-erh factories (such as San Ho Tang, whose Xi-Zhi Hao [Double Happiness] line has set the standard for premium pu-erh) have begun producing boutique-quality pu-erhs based on leaves picked from specific mountain old-growth plantations in Yunnan. These unblended productions often feature the highest quality, largest, and most beautiful pu-erh leaves available, and produce flavor that puts many plantation-sourced cakes to shame. However, blended and unblended single-region pu-erhs both have their merits; blends tend to have a larger breadth of flavors, while unblended pu-erhs tend to be more subtle and possess a more distinct character.
Pu-erh does have somewhat of an "acquired taste" for many people, but brewing it correctly can aid in enjoyment. First, you've got to get some leaves--using a knife or pick, break some leaves off of the cake as gently as possible, preferably from the side. The fewer broken leaves, the better the tea will taste. Traditional Chinese Gong Fu (to be described in a future post) preparation is ideal for pu-erh, since it brings the tea's flavor out little by little in a less overpowering way. For this method, you'll want to get your gaiwan or clay teapot about 1/3 full with leaves, rinse with boiling water for about 20 seconds, and discard the water. For future infusions, steep the tea for a short amount of time (20 sec or even less) with boiling water, gradually increasing the steeping time as the flavor decreases.
Brewing Western style, it's a good idea to use roughly 1 tsp of leaves per 8 oz cup, pouring slightly cooler than boiling water for sheng pu-erh (since you'll be brewing fewer leaves in a larger amount of water), and steep the leaves for 2-5 minutes the first time, depending on your taste. Like any tea, it's all a matter of taste, and you should experiment to find out how you like it best.
Pu-erh's ability to improve with age is probably the quality that has made it especially popular with wine-drinking Westerners in the recent past. Both sheng and shu pu-erhs can improve in flavor with a few years of aging: sheng pu-erh improves the most dramatically and can be aged for over 50 years(!) with continuing flavor improvement, while the usefulness of aging shu pu-erh usually peaks at around 15 years. Within 10 years of aging (different pu-erhs age at different rates), the flavor of sheng pu-erh will mellow considerably--bitterness and smokiness will subside (if not disappear completely), the mouth feel will become smooth, the liquor will darken, and the tea will last for more infusions. The leaves of the cake will also change in appearance (compare the leaves in the picture on left of a 1980's with the young sheng pu-erh cake pictured above, then compare it with the shu pu-erh). For shu pu-erh, aging generally results in the reduction of "off" flavors, like slight dirtiness or mustiness, but it's never as dramatic as the flavor transformation seen in sheng pu-erh. It's also important to note that aging an inferior quality pu-erh won't turn it into a superior one! Although it will mellow out, inferior sheng pu-erh is likely to produce somewhat bland or shallow aged pu-erh. Not necessarily bad, but also not magical transmutation. What's the best way to know if a pu-erh is age-able? Taste it! Complexity and delicious flavors in young sheng pu-erh is a good measure of aging potential, and it's a great idea to taste your aging pu-erh as time progresses to see if your decision was a good one. There's no substitute for experience, though, so it's a great idea to experiment and try both un-aged and aged pu-erhs--you'll start to recognize flavors from young pu-erhs in old pu-erhs, and it will all start to click!
If you plan to age pu-erh yourself, here are a few basic guidelines: pu-erh should be stored in a relatively cool, dark, dry (very important) place with exposure to airflow (airtight conditions will eventually kill the microorganisms responsible for the pu-erh's aging) and an absence of strong odors, particularly food odors, since the pu-erh leaves will absorb strong smells. In general, if it's comfortable climate for a person, the pu-erh should be okay. A good closet or cupboard usually does the trick.
In Asia, pu-erh is sometimes stored in very humid environments. This type of storage is sometimes referred to as "wet" storage or more euphemistically as "traditional" or "Hong Kong" storage. The reasons for wet storage are multiple: unscrupulous vendors may be attempting to artificially "age" sheng pu-erh via a moist environment, or they just may not have access to a humidity-controlled warehouse. In any case, approach these pu-erhs with caution--although this type of storage can speed the aging of pu-erh, it can also result in unsafe growth of mold and other non-ideal "life" on your pu-erh.
Generally, I recommend sampling a pu-erh before buying an entire cake whenever possible--this way, you'll get tasting experience and you'll know firsthand if you like the pu-erh or not. Most high-quality vendors offer samples, and I'd only recommend buying a cake without sampling if you've already dealt with the vendor and trust their quality control. Also, rather than shelling out big money for a lot of aged pu-erh, I recommend buying either premium young or premium mid-aged pu-erh; you'll save a load of money, and if you buy high-quality, you'll be enjoying your tea more within a few years or even when it's young than if you bought mediocre aged pu-erh (or worse--faked aged pu-erh!) at an expensive price.
At Miro, we're committed to offering a broad range of pu-erh; our selection includes both sheng and shu pu-erhs in loose and cake forms, and we carry a range of ages from recently-produced to around 10 years old. We offer premium pu-erh as well as great value-for-price pu-erhs, and we're happy to let you sample the pu-erh before you buy! If you made it through this entire article, thanks for bearing with me--I hope you feel more familiar with pu-erh and educated to make smart buying decisions. Questions are always welcome, and stay tuned for in-depth tasting notes for some of Miro's recently-acquired premium pu-erhs!