Monday, October 13, 2008

Perspectives on Storing and Aging Pu'er Teas (iv): How to Store (and Not to Store) Pu'er


[[EDITOR'S NOTE: The series continues with this, Niisonge's second instalment. Parts i, ii, and iii of the series can be read here, here, and here.]]

What’s the Best Way to Store Pu'er?

People always ask: “What’s the best way to store pu'er?” But that perhaps isn’t the question to be asking. Maybe the question to ask is really: “In what ways should you not store pu'er?” Let’s take a moment to look at some dos and don'ts of storing pu'er.

Storage Environment

What kind of an environment is not good for pu'er? I currently live in Fuzhou (Fujian Province, People's Republic of China) and I have also lived in Longyan, in southwest Fujian. Both areas are tea-producing areas, by the way. And the climates of the two places are similar. Summers are very hot and humid. In the house, the relative humidity often tops 90% -- day in and day out. In the autumn and winter, it rains quite often, though it’s drafty and cold in the house. But still, the humidity in the house is quite high, usually around 80%.

Mr. Pu'er

You know, I’m quite famous in Fujian now. Everyone calls me Mr. Pu'er. Just looking at me, total strangers know me well -- but from smell rather than from sight. See, all my clothes smell of pu'er. They all have that characteristic scent reminiscent of an aged pu'er. But I didn’t get this moniker because I know a lot about pu'er. In fact, my knowledge of pu'er is as infinite as the Yellow River as it flows into the sea. Ok, maybe I made all of that up. People don’t really call me Mr. Pu'er, but I swear, all of my clothes really do smell like aged pu'er! (And in case you didn’t catch that, the Yellow River sometimes does not flow, or even trickle into the sea. The water gets all used up before it reaches its destination.)

I store my clothes in a wardrobe. And some are stored in suitcases; and others are just hanging in the bedroom. After only a week, they all smell like pu'er. But I never actually store pu'er in my bedroom (well, maybe I did briefly -- for a month or so -- but that’s it). No, that distinctive pu'er fragrance (and we all love that fragrance, don’t we?) comes from the fact that both the humidity and the temperature are high in Fujian (as they would also be in Guangdong, Guangxi, parts of Yunnan, Hong Kong, Taiwan, etc.). Because of this combination of high temperature and high humidity, things get moldy quickly.

Here are some examples:
• My nice suit got moldy. (stored six months in a wood cabinet)
• This white cotton shirt was stored under a few other clothes, in another cabinet. It’s not white anymore. (Stored six months)
• We have a healthy spore population in the bathroom -- which is quite exciting. (Over one year of growth). OK, nobody ever cleans that area of the bathroom -- it’s too darn scary!
• Some flecks of mold in the cupboards. This was post-cleaning; it was much worse before. (Six months)

I would have to point out that time is not really much of a factor here. I stored a seldom-used briefcase for just three months, after which it was fully enveloped in white mold.

Under these conditions, in this environment, if this is what’s happening to my other belongings, then it is also happening to my pu'er.

Is this a good thing? Ok, maybe some kinds of fungi are delicious, like tea mushrooms (Agrocybe aegerita) -- 茶樹菇 (cha shu gu) as they’re called in Chinese, which grow on tea-oil trees (油茶樹, you cha shu or Camellia oleifera) -- and these are some of my favorite fungi to eat. This kind of tea fungus is good; but not the kind of fungi that tend to grow on top of pu'er.

If there are fungi growing on my things, and this quickly, think about what they can be doing to pu'er stored under the same conditions. Kind of scary, isn’t it? How is that kind of growth -- at that speed -- going to affect those bing chas? And how, especially, is it going to affect the flavor and aroma of pu'er? Of course, the tea will have a moldy flavor, and a moldy aroma, but how pronounced or strong that mold flavor and scent are, in comparison to the delicate flavors and scent of the tea leaf, is something to be considered.

Pu'er stored in this type of environment (high-humidity, high-temperature) is known as wet-storage. In natural environments where this occurs naturally, such as in Fujian or Hong Kong, sheng pu'er will tend to age relatively quickly. But the downside is that this quick aging, like the quickly aged factory processed post-fermented pu'er (shu pu'er) just won’t have the flavor and aroma and quality of a pu'er that has been stored properly and slowly aged over a number of years.

Moldy pu'er is not synonymous with aged pu'er. Though some aged pu'er is moldy, and the mold growth on top of the pu'er can tell you something about how that pu'er was stored -- it was at one point wet stored, thus creating all the mold growth -- it is not indicative of a good, aged pu'er, because it wasn’t properly stored.

And if you were to break open that cake, and brew it up, you would know from the aroma and taste that it’s just not as good. How exactly would it taste? It would taste moldy! That cake of pu'er would taste better if it had not been wet-stored.

Yes, wet-storing pu'er can speed up the aging process, often dramatically. But the resulting “aged” pu'er is not the same. So storage in a high-humidity, high-temperature environment is NOT GOOD. And when you see a moldy bing cha, then you will immediately know: improper storage. Improperly stored = flavor won’t be as good = not a good buy.

Have Mold, Will Go ...

Ok, before you all go running off to the Gobi or the Taklamakan desert to store your cache of pu'er in the driest conditions possible, you should know that storing pu'er to age it in such a dry area is also not good. Of course, you could go to Death Valley too. But, unless you’re there because you’re into extreme tea drinking, too dry is not good for pu'er. So when you take your bings to the Burning Man, it’s not going to be beneficial to aging that pu'er. Neither is sunlight good for your sheng. So don’t take your pu'er along with you when you go for your fun in the sun. And no beach parties for the pu!

On the other hand, the microbes in sheng pu'er are oxygen-loving (just like you and me), so make sure you give them plenty of ventilation.

It’s Alive! It’s Alive!

Pu'er actually has quite a few organisms (fungi and bacteria) in it, like Aspergillus niger (黑麯黴, hei qu mei); 青黴 (qing mei) or blue mold -- actually a type of Penicillium; Penicillium chrysogenum (產黃青黴, chan huang qing mei); Aspergillus clavatus (棒麯黴, bang qu mei); Aspergillus glaucus (灰綠麯黴, hui lü qu mei); Rhizopus chinensis (根黴, gen mei); Lactobacillus thermophilus (乳酸菌, ru suan jun); Saccharomyces (酵母屬, jiao mu shu, a yeast); and other beneficial or benign organisms. These colonies of organisms live in the pu'er. So think of your pu'er as itself a living organism. And treat it as a living thing. Living things need conditions conducive to life, such as air, comfortable temperatures, comfortable humidity level, and so forth. So pu'er should be stored in an odor-free environment, yet be allowed to get some air. And pu'er ages best (ideally -- slowly) stored under the same conditions that people find comfortable for living in -- that is, similar room temperature, and comfortable humidity levels. Likewise, changes in seasons, changes in ambient temperatures, changes in humidity, and regular air flow all are beneficial to the organisms in pu'er. These all act to help pu'er to age and mellow gracefully. The colonies of organisms in pu'er will grow, expand, and die back; some microbe nations will rise, some will fall, some will dominate, etc. This is all a natural part of the aging process. So get with the cycle, and remember: your sheng pu'er is alive.

Now you know how to store your sheng pu'er. What to store your pu'er in -- that’s another question.

NOTE: 'Wet Storage' is not to be confused with the post-fermentation process, 渥堆 (wo dui, i.e. 'moist heap'), which is meant to speed up the processing of pu'er, or shu pu'er (熟普洱) in the factory.


Fida said...

Gee, now you did something to me:-) After reading that post I run to my pu'er and now I am really not sure wheter my pu'er is moldy or I am paranoid (or was modly at one point?). Some of the leaves look grayish. What's agirl to do?

Warren said...

Just remove it from the wrapper, and air it out on a shelf for a week or two. If it's moldy, that should clear it up.

darwin said...

i have the same condition here in manila, but our humidity levels are lower on the 65-85% range,

i do experience dampness on the tea cakes and they have a moldy or wet bamboo smell to it when i bring the cake near my nose to smell, i store all my shou puerh in a box in a place where there is regular change of air,
am i doing the right thing?

can you share with us how you "protect" your tea cakes from the humidity in your place?


Warren said...

Darwin, you might notice during the rainy season, mold growth is more pronounced; and then after the rains, the mold recedes. The same thing happens in Fujian or Guangdong. Some pu'er drinkers say it's natural, and they don't do anything about it.

Placing it in a box where there is airflow is ok.

But even better is to store them on shelves in a room with a dehumidifier.

In Fuzhou, there's not much I can do to change the conditions. So I just store them in cotton bags, and hang them up off the floor. And let them air naturally. And if it's sunny, I might hang them up outside (still in the bags) to get more air. That's the best I can do.

MarshalN said...

I think I disagree on your definition of "wet storage". Wet storage, or shicang in Chinese, generally refers to puerh that has been stored in ARTIFICIALLY enhanced environment -- high humidity, high temperature. If you store things at room temperature, even if it's in Fujian, it shouldn't be considered wet storage... moist storage, perhaps.

The key difference is whether or not you left it in an environment with artificially elevated levels of humidity and temperature. Given how much mould grows in your house, maybe that's a sign that your apartment is particularly wet. However, I think most people don't live with nearly as much mould around them.

Tuo Cha Tea said...

Those pictures were quite scary... mold on everything... brrr...

Warren said...

Marshall, there's wet storage and then there's wet storage. And of course, there's dry storage too.

Wet storage means conditions of high temperature, high humiidity, and to some degree, low air circulation that causes the puer to age quickly. Now, this kind of wet storage or "shi cang" (濕倉)happens naturally, as I have described in the article. But then, this can also be done artificially too - to speed up the aging process. But that's kind of scary, so I left that out.

So wet storage does happen naturally (thought not ideally) in the environment, as in Fujian, Guangdong, etc. Of course, I left out what that high temp./high humidity environment can do to fungal growth on human skin. You get all kinds of nasties like ringworm, athlete's foot (called Hong Kong foot in Chinese 香港腳), jock itch, etc.

Then, there is also dry storage or gan cang (乾倉), which is by far the best method to age puer naturally and slowly.

darwin said...

thanks warren,

i think so far, from all that i have researched and read, i think i'll just be storing my tea in a cardboard box during rainy season, and hopefully i'll be able to get big clay terracotta jars to put all my tea in and store them there, my living room (where i store my tea in) is really very very big and i dont think its practical to use a dehumidifier, so ill just leave them to age there, if it really gets very wet, then ill transfer them into a small room to get a dose from the dehumidifier, or perhaps out in the sun when the sun finally comes out...

a few questions thou...
isnt puerh "afraid" of the sun? will putting it under the sun affect the taste?

also, would you advice using clay terracotta jars to store my tea in?

thanks very much

Warren said...

You're right, sunlight is not good for pu'er. But when things get really moldy - clothes or whatever. We hang them up on the balcony to get some air and sun. Even dried herbal medicines are placed on large bamboo baskets (or even directly on the ground) to sun for a time to make sure they don't go bad with mold.

If you have a major mold problem, then they are going to need some airing out - take them out of the wrappers, scrape or brush off the mold. Then air them for a week or two on a shelf in the house. If you notice that they have a lot of moisture, then wrap them up and put them in the cloth bags and let the heat of the sun and airflow (not sunlight) dry them out for an hour or two.

And clay terracotta jars should be ok to use - they can breathe. Lots of people use those in China too. And in the next article, you will see about that.

darwin said...

thanks warren,

i'm eagerly waiting your article on the jars, mr cloud also said that he is planning on posting something about jar storage, horayyyy! =)

here in the philippines, we have "vigan jars." the technique used to make them came from early chinese immigrants from jin jiang fujian, which my grand parents are from also. they use a local clay which they say are of good quality and those jars are used to store and ferment vinegars and baci wine to name a few. as my research goes, they are quite porous and would be able to let the tea breath inside, and the best of all, they are very very inexpensive.

Warren said...


Yeah, experiment with those jars and see what happens. You will only know by trying. And then, you can all tell us how well those kinds of jars are suited for storing and aging pu'er.

Fida said...

Thank you Warren for all the good info.