Monday, June 23, 2008

Perspectives on Storing and Aging Pu'er Teas (i)

by CORAX & Co.

EDITOR'S NOTE: Recently I read a provocative article by Jinghong Zhang on storing pu'er tea (with a link to an earlier piece by the same author). Zhang brings up a number of interesting points about the nature of pu'er tea, and the thorny question of how best to store and age it.

Because there is so much controversy on the subject -- and because the purchase and collecting of pu'er tea can often represent a sizeable investment of both time and money -- I thought it would be well worth our while to consult some knowledgeable figures in the global tea-drinking community, and to assemble their thoughts on the matter. Opinions differ across the world, of course, about what happens to pu'er teas as they age, and about how to protect one's stash and optimize the aging results; and I knew that the opinions even of these tea mavens would not be identical. But indeed that was one reason why I thought it important that we take note of a broad spectrum of ideas.

So here for your information and delectation, gentle reader, is a collection of observations (listed alphabetically by contributor) on various aspects of storing and aging pu'er teas: the first in what I hope will be a series of CHA DAO posts on the topic. (I should mention that none of these contributors has seen the comments of the others, prior to the publication of the entire composite post here.) Your own comments and queries are, as always, welcomed to further the conversation.

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» Stéphane ERLER, resident of Taiwan and master of the well-known TEAMASTERS blog, writes the following:

By now, I think that most people are aware that puerh ages faster in an environment with a rather high humidity level and high temperature. I can clearly smell this, as summer approaches in Taiwan, from my own puerh stash. It feels much more active than during winter.

I would like to offer a few new perspectives on the subject:

1. Why store puerh or what kind of puerh is worth storing by individuals in the West?

There is a myth that almost any bitter and astringent raw puerh will turn into a wonderfully mellow and fragrant tea if you give it enough time (and proper conditions) to age. This myth has helped fuel the interest and speculation in puerh in recent years, as it promises big returns on small investments. The myth also helps a lot of buyers to feel less bad about their purchases: if it's not good now, there's a good chance that it will be better in a few years. However, these low-grade puerhs are probably those that need the most transformation, the most humid and hot environment possible, in order to become drinkable. In that regard, hot and humid Hong Kong, Taiwan, and Malaysia offer better conditions for this than most places in the US or in Europe. So I don't see much justification for tea drinkers in the west to age such puerhs by themselves.

High-grade puerhs, on the other hand, don't offer a perspective just to become drinkable (they already are very good), but to become exceptional. I see some parallels to red wines here: when a collector purchases wine for the long term (for the birth of a baby, with the intention to give or drink it when the baby is adult), then he would choose a grand cru classé, a top grade. A medium grade wouldn't do and certainly not a low grade. A slower maturation isn't a problem if you already enjoy the puerh as it is today!

For a fast maturation, critical mass (a big quantity) is another advantage that merchants have. But for slow and careful maturation, a smaller quantity can become an advantage (see below) for individuals.

Storing is ultimately a question of what will stand the test of time. There are two kinds of items worth collecting: very personal or top-quality items. And even if, as a parent, you collect your kids' drawings, you will focus on the nicest ones. Or, for your photo album, you will only select the best shots. As a tea drinker, the aim of storing is to remember the best about your tea discoveries. It shouldn't be about remembering the bitter experiences you underwent 20 years ago.

2. How to judge what young puerh is worth keeping?

There should be some sweetness, purity in the mouth, and a throat that doesn't shrink when the tea flows throw. Then, the yun, the aftertaste, should be very long. The whole experience should already be a pleasure. (A lot has been written on that subject already).

3. Storage advice.

Not all puerh warehouses are very clean. Many merchants simply store their puerh in an old, damp basement. The risk of mold is quite high, and the fragrance of puerh stored this way is not always nice. This is where home storage has the potential to be better than mass storage. Keep you puerh away from bad smells, in a clean environment. That also means that raw and cooked puerh should be kept separately. You don't want your puerh to be contaminated by other smells, but to keep its original purity.

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» GERALDO, a stalwart among CHA DAO contributors, provides these observations:

Neither I nor any of my friends has stored a teacake for twenty years. I’ve met one or two older Chinese gentlemen who have stored pu’er for decades, but I’m not in communication with them. My knowledge of storing pu’er, therefore, results from the too-often contradictory mandates gleaned from Internet sources -- blogs and forums. And I doubt those authors have held onto a cake from manufacture to maturity. I suspect that some rules for storing pu’er are rather like urban legends: We repeat what we’ve heard, regardless of the absence of empirical data. This is the great pu’er conundrum, the conshengdrum.

Sad irony: Unless we begin collecting pu’er in our twenties, we cannot actually use what experience teaches us. Before my first sheng teacakes age, more then twenty-five percent of my life will have elapsed.

When vendors refer to five-year-old teacakes as “aged,” who can we trust? Sheng ages at glacial rates. Buying nascent sheng is an expression of optimism.

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Words change. My hero Samuel Johnson wrote of this in his preface to his great Dictionary. New words spring to birth and their definitions morph at light-speed. In the context of pu’er, a prime and apropos example is “wet.” Just four years ago here in the West, “wet” referred to young pu’er that had been speed-aged so it could be foisted upon the unwary in the guise of aged pu’er. Unscrupulous antique dealers hang new chairs from ropes and dangle them in the surf for a week or two, and then sell the “antique” chairs for huge profit. Wet-stored pu’er was an all-or-nothing construct, like a light switch, on or off, wet or dry.

Today, “wet” has a far different meaning. In current usage, all aged pu’er is to some extent wet-stored. According to today’s parlance, if it were truly dry-stored, it would be desiccated, mummified. Now “wet” is any point along a big defining continuum, and we consider it in terms of the relative humidity at far-flung storage locations. We think about degrees of "wet" based upon prevailing weather in cities like Guangzhou, Kunming, Shanghai, Hong Kong, Taipei, Kuala Lumpur, San Francisco, Paris, Houston, and New York. We also consider it in terms of airflow in storage locations, 1988 Ching Beeng being a famous example of airflow in the aging process.

When I first drank aged sheng, "dry-stored pu’er" was any pu’er that had not been nefariously speed-aged. By today’s definition, that wonderful sheng was more or less wet-stored--depending upon the relative humidity and airflow in the storage location. Much is written now about westerners’ strange aversion to perfectly good wet-stored pu’er, but that perception of western taste stems from semantic change rather than aesthetics. Let us put this subject to rest. Westerners have an aversion to wet-stored pu’er under the old definition, not the new. No one likes pu’er that has been ruined for the sake of profit through fraud. Words change faster than sheng matures.

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In ten or fifteen years, we will see, I’m certain, a rather large amount of home-stored sheng appear. This will be an exciting time! I am very curious to know how pu’er aged in air-conditioned homes will have matured. Remember that regional humidity will not really apply to the extent some might suppose. Given how most of us live, humidity (or lack of it) outside is not reflected by conditions inside. My part of the world is quite humid in the winter, but my windows are closed because it’s cold. My part of the world is somewhat drier in the summer, but my windows are closed because it’s hot. I grew up in Iowa where the summertime relative humidity outside would often approach one-hundred percent. I’d wager that most pu’er collectors living in Iowa today have air conditioners. Even when heaters and air conditioners are not switched on, interior and exterior relative humidity do not really coincide. Nevertheless, places in the tropics will be more humid inside. My pu’er-collecting friend in Singapore worries about removing water from the air. I worry about adding water to the air. I humidify; he dehumidifies. But we both have air conditioning, and that ameliorates the biggest effects.

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At my age (and I’m far younger than ancient Corax), I’d be crazy to spend much money collecting nascent sheng. Further, I’m an impoverished teacher, so I ride a Yamaha rather than a Harley. I can no longer afford to buy good sheng from the seventies. I now and again will split an eighties cake with a friend or friends. For the most part, I roll the dice and buy nineties cakes, and those arrive in various states of wetnitude. Sometimes I am a lucky little pu’er-head, and mildly wet-stored pu’er emerges from the SAL parcel. More often, though, the nineties pu’er arrives rather wetter than I prefer.

My tea-teacher has long advised that I expose newly-arrived pu’er to the air for at least two weeks prior to tasting it. I have learned that shu is incredibly better when aired. I flake some of it into a bowl and cover it with a paper towel. Then I tap my foot for fourteen days. When nineties sheng arrived with the leaves somewhat the worse for wetnitude, I used to despair. I’d consider my money ill-spent. But I have learned now not to judge nineties pu’er until it has aired for two months. I flake some of it up and leave it in a bowl as I do with shu, but for sixty days rather than fourteen. I’ve witnessed some truly tremendous evolutions. I cannot overstate this recommendation. There is but one problem: Too often a vendor’s supply sells out before I can judge it. C'est la vie.

In A Glossary of Chinese Puerh Tea, Chan Kam Pong (a.k.a. “Cloud”) classifies pu’er into three categories: “mildy wet storage,” “medium wet storage,” and “seriously wet storage.” I’ve learned from correspondents that Cloud has formulated a procedure for revivifying seriously wet-stored pu’er, and I’d like to learn the exact specifics of his procedure. But lacking that knowledge, I am happy my short-term solution has salubrious results, albeit that it requires the breaking-up of a cake or portion thereof. Not only does the sixty-days-flake-up-and-exposure procedure improve the taste, but it improves the appearance as well.

Even some good adolescent pu’ers will improve from airing. As a case in point, I purchased a number of Xia Guan Nan Zhao Brand Fu Lu Shou Xi fang cha cakes, vintaged 1999 and 2004. Some I purchased personally in Guangzhou’s teashops under the tutelage of my Guangzhou friends, and some over the Internet from Jing Tea Shop. Seb and Jing’s tea maestro sent word that I should break up one of the 1999 bricks and expose it to air for two months. The brick emerged from its box a dark olive-green, looking nominally aged and tasting pretty good. Two months later it had miraculously metamorphosed. The leaves were dark reddish-brown. The tea tasted fabulous.

To err is human, but to air divine.

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» TOKI, one of the original contributors to CHA DAO, and master of the classic blog The Mandarin’s Tea, offers us the following notes, links, and images (including a wonderful brief movie on stored Yiwu pu'er):

There are 2 purposes of aging in my opinion: 1. Aging for storage, or 2. Aging to refine taste and development of character. Storage aging comes simply because of: A. Overstock, B. Investment, or C. Unintentional.

For tea lovers, except perhaps tea vendors, overstock leads to storage. Dry storage and wet storage really depend on which climate zone you are living in. Let me use puerh as our topic of discussion, thinking of normal tea lovers:

Wet storage occurs if you are in the tropics with high humidity year round, e.g. Hong Kong, Malaysia, or Florida. Dry storage occurs in drier climates, e.g. Texas, Nevada or Kunming. Added to these is Seasonal storage, which includes places that have pronounced seasonal differences, e.g. New York, Beijing, or Korea.

I can only suggest areas I am most familiar with, since I've been living in NY for over 18 years. New York City is a very unusual area to age tea, not because of its location, but because of the popularity of drinking puerh. Weather here is extreme in every season: super-dry winters with the added factor of central heating; 80-95% humidity in springtime with spring showers like those in London; 100°F (and higher) summer heat, with high and low mixed humidity; and Kunming-like autumns, mild temperature and pleasant 60% humidity. These clear seasonal changes contribute to well-mixed changes in short periods.

Storage aging without refinement can prolong the aging process. Raw-cake storage in NY can take up 3 to 4 times longer than aging in Hong Kong. The main hazard period for tea here is wintertime. The humidity can drop to 20-30% if you have a heater. This critical four-month period is always my concern. Being too dry will certainly hurt your tea, if not "kill" them. If this period of dryness continues more than 6 months, the tea will be in serious hibernation: a long sleep, from which they might never wake.

I have previously discussed the topic of tea aging, dividing it up into three major maturation periods:

First Maturation: around 5 years
Second Maturation: 15-25 years
Third Maturation: 50 years and up

If it is a newly-harvested puerh, the first five years is fine, even if it's stored in a prolonged (5 months) dry climate. But the effect might be a less lively brew, or the taste might not be as promising as the aroma.

If this is prolonged to the second period of 5 to 10 years of continuous dryness, lower than 50% humidity, the tea will be permanently affected.

If tea is in its second period of aging, and was kept in a pretty fine first period, it will continue to develop excellent characteristics which might not be detected in the first period. But if the storage condition deteriorates, then all the work will be spoiled. I have tasted good mature tea in its second stage which was stored badly; the taste came to a standstill as of a 10 to 15 years aged tea, but without life or youth. Many vendors try other ways to make badly-stored tea alive by introducing wet/dry storage depending where the tea stands, for a short period of time, and then to resell them. That could be a desperate attempt which will add only the first few brews with a better soup, but after the couple of brews, the falsity cannot be hidden.

No matter how the tea is stored, there is always something to learn from it -- especially the ones we have stored ourselves. Bad judgment only leads to better techniques and knowledge. Learning from yourself will be a good benefit to judge what you are buying from vendors.

Storage in bulk is the best way: (click on the image for a larger view)

I have seen a warehouse with over 30 years’ aged mao cha storage. Stacks piled up to the ceiling, in a space thousands of square meters in size. This was the best way of storage, I was told. The microclimate that these tons of tea leaves have created will manage the temperature and humidity, and will improve the aging process of the tea. But who, beside the factories, can achieve this? My suggestion is to buy at least a tong if you plan on storage. The more of the same kind of tea to age you have, the better the result will be.

[[Click on the circle in the center of the image, then click the 'play' button on the viewer. Note: the sound-track is not subtitled! :) ]]

I also have an entry on my blog about refining storage; it's a bit of a labor of love. But I do believe it is the ideal way to a better system.

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» Scott Wilson, proprietor of Yunnan Sourcing LLC, brings a Kunming-based pu'er vendor's perspective to the topic:

1. 'How was this tea stored?' as a criterion for buying

Most of the time I am buying teas in whole-case quantities as they are released into the market. Occasionally, I do buy teas that have been aged by others, and this is one of the first questions that I ask. Of course, looking at the tea and already knowing its age can often tell me that it was not aged in Kunming. After brewing teas stored in places like Guangdong or Fujian, it is often quite obvious to me that the tea was stored there due to the unique smell and slightly moldy taste that it has. I also tend to notice a dry or scratchy throat after a drinking session of wet-stored raw Pu-erh.

A few months ago I bought some 1998 Xiaguan tuos that had been stored in Lanzhou (Gansu) since that time. Visually there was very little change to the tuo, and even the brewed leaves were still quite green after ten years of storage. The taste of the tea itself was aged, but the intense cha qi was still present. Lanzhou is drier and colder than Kunming, so after my experience with this Xiaguan tuo stored there I knew that there are places even slower than Kunming for aging Pu-erh.

I would always prefer even a very dry storage condition over teas stored in wetter conditions like Guangzhou, Taiwan and Fujian. This is just my own bias, but I don't like the taste and feeling of most the teas stored in these areas.

2. Wet storage: Different meanings of the term

Wet storage typically refers to teas stored in more humid conditions. These are natural conditions that cause a speedier post-fermentation of the tea. The traditional Guangzhou and Taiwan storage of Pu-erh was not designed to speed up post fermentation; it is just due to the climate in those areas. People from these areas tend to "be OK" with the wetter taste, and will often complain when served dry-stored Pu-erh from the same factory/vintage.

However, in recent years -- as aged Pu-erh has become more sought-after -- the creation of intentionally wet-stored Pu-erh intended to simulate aged pu-erh has become a problem. This method of creating an aged pu-erh is typically done by spraying water on "mao cha" and then drying it out, making it wet again and then drying it out (sometimes with ovens or electric heat). This mao cha is then compressed into cakes or bricks that look aged, but when it is brewed, it will give off strange odors and taste that would fool only those who had never drunk properly aged pu-erh. Cakes are also stored in intentionally wet conditions and sprayed with water, until they mold through and through. Then to remove the visual evidence of mold, they are baked in oven rooms at very high temperatures to break down the mold. As you can imagine, this kind of tea is bad for health.

3. Wet storage: Good or bad?

Until there are medical studies that can prove that the molds present in traditional wetter stored Pu-erh are harmful, I think this will be a question of personal preference.

On the other hand, intentional wet storage to simulate aged Pu-erh is definitely bad for health! I have met scores of people sickened by this type of tea. While anecdotal, I do strongly believe that simulated aged Pu-erh is dangerous to drink!

4. The interplay of time and climate as storage

The interplay of time and climate as the catalyst for aging Pu-erh is practically unlimited! I think the question on everyone's mind is: Where is the best place to store Pu-erh? I don't think there is really a single answer. If you are like me, and revel in young raw Pu-erhs that deliver a punch in the gut and an energetic high, you won't be worried about getting your Pu-erhs on the fast-track to old age. But if you did want find a place where your raw Pu-erh would mellow faster, where would that be?

I have long considered the idea of regional Pu-erh banks situated in ideal locations for storage. The one located in Yuanjiang (Yunnan) takes advantage of consistently warm weather and a higher humidity level. It seems that these two conditions are the biggest factors in aging Pu-erh. Too much humidity is not good, as you want to preserve the natural qualities of the tea without introducing molds or spores. You want it change, but not too fast. Too fast, and you lose the natural qualities of the tea!

Making a decision about what the ideal climate would be for aging Pu-erh might be decided after getting Pu-erh stored for 5 to 10 years in different areas. Ideally if you could get the same factory/vintage/recipe tea that was stored in Kunming, Shanghai, Guangdong, Xishuangbanna, and Malaysia, you could see how each areas unique climates have aged the tea.

It will be exciting to taste North American and European stored aged Pu-erh in the years to come. We will all learn a lot as Pu-erh becomes a long-term resident in places all over the world!

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Anonymous said...

fantastic. thank you for compiling this - an excellent compilation, and more in common than i imagined there'd be between the various perspectives.

informative - can't wait for (ii)


~ Phyll said...

Thank you so much for all the perspectives! I do have an immediate question: I store a good part of my pu'er collection in a wine cellar. They are stored in a pitch dark, wooden cabinet that is closed (not air tight...there are gaps on the edges of the doors that allow minimal air movement), constant 57 - 58' F and 65% humidity, year round. The teas are 95% sheng from 1998 onwards.

Is this a good thing? Or do you think there may be potential problems in the long or in the short term?



toki said...

Phyll-If your cellar is not a cedar room, that will be a perfect climates for fine aging. If not, you might end up with cedar instead of camphor in your brew... might be a good favor to have : P - Toki

David Lesseps, LAc said...

Humidity-wise, Phyll's cellar sounds ideal. What do you think about the temperature? Does 58F sound too low? How much does temperature play into the equation?

Corax -- thank you very much for this pulling together this compilation. One question I would like to pose to the experts is the variable of air content. I live in San Francisco which is known for sour breads made from wild starters -- the product of some lovely yeasts that are abundant in our region. How much does regional variation in micro-organism populations affect the long term aging of teas? Is the fermentation of puer more a result of what is inherent to the leaf or of what is introduced?

~ Phyll said...

Thank you, Toki. No, it's not cedar. I can hardly afford another expensive hobby of puffing Montecristo's. :) The wooden cabinets are pretty much odorless to the best of my senses. Had it given off any odor, pleasant or otherwise, I would not have placed my teas there.

My concern is if it is better to let the teas experience seasonal fluctuations rather than to the constants of a cellar.

Re: temperature...I would think that it would affect teas the same way as it would wine -- i.e. it slows down the aging process. In pu'er, therefore, it slows down the speed of post-fermentation. But I honestly am just drawing a conjecture based on what I've learned about wine storage.

Thanks for all your advise (and any forthcoming ones).


corax said...

[david] Corax -- thank you very much for this pulling together this compilation.

[corax] david, you are most welcome. thanks for your comments and questions -- and ditto to all of you, our CHA DAO readers! [and stay tuned for the next instalment(s) of this fascinating conversation ...]

Anonymous said...

I live in HOT, DRY, Nevada and have thought long and hard about this subject. Unfortunately I don't have most of the options that others have and storage for me is a challenge. Maybe it's a blessing is disguise though... hopefully some day I'll have good results and be able to share them with the rest of the world... Hopefully...

The solution I've been trying is to store them in ziplock Mylar bags (I DO NOT use oxygen absorbers or suck the air out). I get them to a decent humidity in a sealed container for a few weeks and then put them into ziplock mylar bags and seal them up. I then keep the bags stored in thick ceramic crocks to keep the temperature consistent and to keep severe temperature fluctuations and drafts to a minimum. They're stored indoors in a climate controlled environment where the temps rest from the high '60s in the winter to high '80s in the summer.

I check on them once or twice a year to air them out a little and to make sure the humidity is at a decent level (60's) and that there isn't any mold.

And I know... "airflow, airflow, airflow". But the air here is DRY and sucks the moisture right out of everything. It's just not option; even in the cool seasons. When the moisture gets sucked out, it has to go back in. I do this by putting them into a tupperware container or large tin with a humidor button soaked in spring water. I also use moistened cotton balls that I'll put into a discarded lid or an unused tea-lite holder. I NEVER spray my tea down... (shakes head).

And from what I understand, many "iron cakes" turned out just fine. They were pressed TIGHTLY with only microscopic amounts of air getting through to the center of the cake. I tend to think much of the fermentation process has to do with enzymes and bacteria as much as air flow. Sure, air will speed up the process, but does faster always mean better? Maybe slow and steady wins the race?

As long as there is a little air, a little moisture and the right steady temperature present (and no "off" smells around), I think it's going to go good. Of course I could be wrong.

Only time will tell I guess...