Regarding long term storage

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Re: Regarding long term storage

by Drax » Nov 10th, '12, 11:59

I recommend checking out this wiki description on mold growth (see the "causes and growing conditions" section).

Although it does mention that air flow "might" help lower the chance of mold growth, the primary requirements for mold growth are temperature and humidity. It's unclear how much air flow will help in an area that's really humid and hot.

Still, it does suggest for those of us with pumidors (or even in summer months) that we should be really careful of the combination of temperature and humidity -- again, regardless of air flow.

I would assume that you have mold everywhere, and that's it just waiting for the right conditions to grow.

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Re: Regarding long term storage

by shah82 » Nov 10th, '12, 12:34

I think the air flow is about ensuring no pockets of drastically higher humidity.

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Re: Regarding long term storage

by theredbaron » Nov 10th, '12, 13:00

Drax wrote:I recommend checking out this wiki description on mold growth (see the "causes and growing conditions" section).

Although it does mention that air flow "might" help lower the chance of mold growth, the primary requirements for mold growth are temperature and humidity. It's unclear how much air flow will help in an area that's really humid and hot.

Still, it does suggest for those of us with pumidors (or even in summer months) that we should be really careful of the combination of temperature and humidity -- again, regardless of air flow.

I would assume that you have mold everywhere, and that's it just waiting for the right conditions to grow.
Interesting article. It says that ventilation is important as a first step remedy for a mold problem (and i assume prevention as well), and that anything above 60 percent humidity is dangerous.
I would therefore be very careful with these pumidors indeed.

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Re: Regarding long term storage

by tst » Nov 10th, '12, 15:00

theredbaron wrote:I am neither a biochemist, nor a physicist, or anything related. But i have to say that some of the humidity cabinets shown in this discussion here do scare me.
I live in a wooden house in hot and high humidity climate where mold, especially in the rain season is a constant worry. In days of strong monsoon rains the humidity jumps to insane levels, and wood and leather is quickly covered in a thin layer of mold. It's especially bad in enclosed spaces, such as in closed cupboards, boxes, etc., where trapped moisture can't escape easily. That can happen within a day or so.
I have once discovered a few cakes of Pu Erh that i have forgotten in a wooden box for about ten years, most were OK, after airing them out for a while, but one in particular was completely off, and had a very musty smell/taste.
I think I understand what you're saying Baron. Perhaps, though it would almost defeat the purpose of the custom wood cabinets being made, having small air holes (approx. 1") for improved circulation would address the issues you bring up. Positioning the internal fans to circulate air in on one side and out on another would improve circulation too.
Open water and heat in an enclosed space without airflow, creating a tropical micro climate, can be a recipe for disaster. I think the numbers game here is a bit misleading, looking at exact levels of humidity, or temperature. Pu Erh's are aged successfully in many different climates. Hongkong, KL, or Singapore have quite different climates, but each has a history of excellent aged teas. But especially in KL and Singapore, being hotter and more humid, care has to be taken regarding mold (i have seen and drunken quite a bit of Pu Erh from there that was a bit too musty for my taste).
I'm curious what the specific values for temperature and humidity you're referring to. You're right ... open water and heat in an enclosed space without airflow could be a recipe for disaster, but it really depends on the numbers. It sounds as though you're main point is that air circulation is a larger factor for mold growth than the humidity and temperature levels (or are you just saying it is only an additional factor and not more important?). Too hot and humid, regardless of airflow, will cause mold growth if spores are present, and the link from Drax states that increased circulation will actually increase the circulation of spores, possibly causing increased mold growth.
I believe that in a more dry climate it would be more important, and much safer, to find ways to raise humidity in the entire room the tea is stored in, than just in a small enclosed space, to enable more airflow and ventilation (that doesn't mean a heavy fan, just natural air circulation). That means in a tea storage room not to have aircondition, have a humidifier, and regularly air the room (as one should anyhow do).

Open bowls of water combined with heat, all in closed proximity to tea and hardly any air circulation might turn into a breeding ground for mold. I think that a healthy amount of air circulation is more important than desperately keeping humidity levels up to a specific number (and 70% is rather high humidity, and dangerous), especially when that number is reached only by having not enough air circulation in an enclosed space.
If there is some airflow in the pumidor, I'm not sure what difference having an entire room pumidor or a small, enclosed pumidor. The general consensus of having a high tea:space ratio in the storage area means that the majority of the space is tea. To achieve this for home storage without hundreds of kgs of tea, I assumed the space would need to be reduced to achieve an optimal tea:space ratio.

You say 70% is high and dangerous. Is the Rh in your location above this? Below this? Can you provide us with the numbers for your location? Where I'm at in Northern California outside is supposedly 8.9C (48F) and 71%Rh. Inside is maybe 15C (60F) and 65%Rh. We never have to worry here about mold growth in the house regardless of the circulation because it is just too cold. But in order for tea to age at all, I will need to raise the temperature and humidity to levels at least remotely close to the numbers in SE Asia.

Thanks for adding to the discussion. I know many value any input and opinions given, and I do think it is good advice to monitor closely while adjusting temp and humidity. I try to remind myself by reading posts from this now-extinct blog often to remind myself of the very points you bring up ...

http://thegreenteareview.blogspot.com/2 ... ution.html

http://thegreenteareview.blogspot.com/2 ... pdate.html

and the disaster that ensued ...

http://thegreenteareview.blogspot.com/2 ... rn-to.html

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Re: Regarding long term storage

by theredbaron » Nov 10th, '12, 15:54

tst wrote: You say 70% is high and dangerous. Is the Rh in your location above this? Below this? Can you provide us with the numbers for your location? Where I'm at in Northern California outside is supposedly 8.9C (48F) and 71%Rh. Inside is maybe 15C (60F) and 65%Rh. We never have to worry here about mold growth in the house regardless of the circulation because it is just too cold. But in order for tea to age at all, I will need to raise the temperature and humidity to levels at least remotely close to the numbers in SE Asia.

Thanks for adding to the discussion. I know many value any input and opinions given, and I do think it is good advice to monitor closely while adjusting temp and humidity. I try to remind myself by reading posts from this now-extinct blog often to remind myself of the very points you bring up ...

http://thegreenteareview.blogspot.com/2 ... ution.html

http://thegreenteareview.blogspot.com/2 ... pdate.html

and the disaster that ensued ...

http://thegreenteareview.blogspot.com/2 ... rn-to.html
In Bangkok during the rain season on really rainy days the humidity can jump up massively. I have no numbers, but believe me - hot and really sticky.
There are of course many factors, but warm temperature is important for Pu Erh aging, and a certain amount of humidity. I tried Kunming stored cakes, and i saw very little change. But when you have high humidity, then of course mold is a worry. So it's a bit of a balancing act.

The reason why i would suggest instead of just a small enclosed space with high humidity a whole room with moderately raised humidity is that you anyhow air a room at least once or twice a day, leading to natural airflow, exchange of air, etc.

I don't think that Pu Erh needs a constant level of high humidity, and high temperature, certain numbers biblicaly adhered to. You said yourself that you need to somehow create a climate somewhat similar to SEA. But don't forget that on occasion here in SEA teas do rot, or get musty in a bad way in sticky places.

Micro climate is very important. I come from Europe, from a city with many old buildings. While generally humidity is quite low it is still though advised if one lives especially in such old buildings to keep bathroom doors open to air them out after a shower to avoid build up of mold in the walls. Mold can happen in low humidity countries as well, in enclosed and badly ventilated spaces.

Many people say that Pu Erh needs to be closed together to age properly, if possible massive amount of cakes, with not much space in between. I am not so sure about that. I have started with a few cakes, and just left them on a shelf for the first years. Only after a few more years i got a few more cakes, and then again a few more. Now i have quite a lot of Pu Erh. But the first few cakes aged by themselves really well.
People say this, and others say the opposite. Suddenly this way gets fashionable, and then something completely different again.

There is a school of though as well that says that Pu Erh needs seasons, as it needs dormant periods as well, and that it is actually conductive to also expose Pu Erh to the natural climate instead of keeping it in artificially created climates. I kind of believe that this makes a lot of sense. But what do i know?

The only thing i can say is that aging Pu Erh isn't really exact science. A few quite clear factors all agree upon: relatively high humidity and temperature accelerates the aging process. To much can destroy the tea.
Less humidity and temperature slows the process, too little can destroy it as well.
And in between is a large room for experimentation.

A thing i notice here in this forum is that a lot of numbers are always thrown around - exact temperature of the water, exact weight of leaves, exact volume of pots. And now exact percentage of humidity, exact this and that.

Would you believe me that i live entirely without scales, without barometer, without thermometer (actually - the first thermometer in my life i bought when my son had a high fever, a few years ago, when he was a baby)? I still live, and my tea is very nice ;)

I was told by my teacher, when i first started getting into Pu Erh more than ten years ago to just keep it on a shelf, well ventilated, away from direct sunlight, away from kitchen smells, and not to worry too much. Which i didn't. And it worked out fine.

Of course in a drier climate almost the opposite factors have to be dealt with than here. I still though wouldn't worry too much, especially not about exact numbers.

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Re: Regarding long term storage

by tst » Nov 10th, '12, 16:18

I agree about exact numbers, but you have it easy. Living in areas with similar climates to the places puerh has always been aged allows you to just set it on the shelf and forget about it.

However, anyone living in starkly different climates are unable to do this. Perhaps we don't need numbers, however it makes sense to have an understanding of at least the ranges to be more certain that our tea is aging. I'm sure we all would love to be able to just buy the tea and forget about it, but for the majority, the tea would never age (many have worse conditions than Kunming).

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Re: Regarding long term storage

by theredbaron » Nov 10th, '12, 22:56

tst wrote:I agree about exact numbers, but you have it easy. Living in areas with similar climates to the places puerh has always been aged allows you to just set it on the shelf and forget about it.

However, anyone living in starkly different climates are unable to do this. Perhaps we don't need numbers, however it makes sense to have an understanding of at least the ranges to be more certain that our tea is aging. I'm sure we all would love to be able to just buy the tea and forget about it, but for the majority, the tea would never age (many have worse conditions than Kunming).

True.
During the rain season i do regularly smell my cakes, and shift them on occasion - fear of mold.

I do understand your problem. I personally do not like young sheng that much, especially not in larger quantities.

I want to move back to Europe though, and i will then face similar problems as most here do. I have been thinking quite a bit about what i will do with my Pu Erh then. I will have to accept slower aging, but that's not such a problem. One of thoughts was to use a normal room humidifier in the room i will store my Pu Erh then, especially in the winter months when heating will make the air inside really dry.

I guess it will be really problematic for people who live in desert climates, especially in some places in the US. But there is maybe the question if it would not be better to find a storage place in a better climate somewhere else, and keep just the teas you drink in your homes. There seem to be quite a few people from the US with similar issues about storage, maybe you can get together, share and rent a small space in Florida or another more tropical part of the US to store your tea?

Or buy semi-aged teas that have already a few years of storage in more humid climates? Yunnansourcing, for example, has several very nice teas that have been stored for some years in more humid parts of China, and which are not overly expensive.

Also - think about aging other kinds of tea as well. Semi-fermented teas are better to age in drier climates. Aged high quality Wu Yi teas, for example, are a dream.

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Re: Regarding long term storage

by gasninja » Nov 11th, '12, 09:44

Red Barron I think the idea with ageing a bunch of cakes together is that the cakes will all create a micro environment. The humidity will be some what regulated from the moisture content in all the cakes. There is also the idea of micro organism exchange between the cakes? It is also the thought that with a room filled with tea the combined odor of all the cakes will actually enhance the cakes smell, rather than having the smell disapate through excessive air exchange.

I don't see that it matters whether you have a room full of tea or a cabinet full of tea as long as there are a good amount of cakes relative to the space. It is much easier and inexpensive to keep a small area in an environment conducive to ageing than a whole room. I feel that opening my " pumidor" once a day is sufficient for air exchange. I personally don't keep the temp and humidity constant. I think your arguments against a pumidor are illogical. It is strange for you to to sit somewhere where you can leave your cakes out and they will age fine and say we are crazy for trying to create a similar environment.

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Re: Regarding long term storage

by theredbaron » Nov 11th, '12, 10:49

gasninja wrote: I think your arguments against a pumidor are illogical. It is strange for you to to sit somewhere where you can leave your cakes out and they will age fine and say we are crazy for trying to create a similar environment.
Maybe i am illogical...

...but then, if you go up a few posts, you can see a link to some blog posts that show how such a pumidor experiment went wrong.

Q.E.D.

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Re: Regarding long term storage

by Drax » Nov 11th, '12, 11:17

theredbaron wrote:Q.E.D.
:roll:

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Re: regarding long term storage.

by yanom » Nov 11th, '12, 12:35

theredbaron wrote: Maybe i am illogical...

...but then, if you go up a few posts, you can see a link to some blog posts that show how such a pumidor experiment went wrong.
if you go up a few posts, you can see how natural storage went wrong. :mrgreen: But that's not an argument that natural storage must be wrong, right?
theredbaron wrote:I have once discovered a few cakes of Pu Erh that i have forgotten in a wooden box for about ten years, most were OK, after airing them out for a while, but one in particular was completely off, and had a very musty smell/taste.

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Re: Regarding long term storage

by theredbaron » Nov 11th, '12, 12:45

Drax wrote:
theredbaron wrote:Q.E.D.
:roll:

Would you prefer if i would have used a more colloquial vernacular, such as maybe: "hey dude, are you blind or what, calling me illogical when a a few posts up you read about some other dude letting his tea rot in his cupboard sauna?"
Last edited by theredbaron on Nov 11th, '12, 12:51, edited 1 time in total.

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Re: regarding long term storage.

by theredbaron » Nov 11th, '12, 12:50

yanom wrote:
theredbaron wrote: Maybe i am illogical...

...but then, if you go up a few posts, you can see a link to some blog posts that show how such a pumidor experiment went wrong.
if you go up a few posts, you can see how natural storage went wrong. :mrgreen: But that's not an argument that natural storage must be wrong, right?
theredbaron wrote:I have once discovered a few cakes of Pu Erh that i have forgotten in a wooden box for about ten years, most were OK, after airing them out for a while, but one in particular was completely off, and had a very musty smell/taste.
That is basically what i wanted to show here, too much humidity in enclosed spaces can go terribly wrong. For me it was just a cheap cake i bought ages ago in China, no loss. I would dread though the thought that this would happen to the teas i care about.

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Re: Regarding long term storage

by Drax » Nov 11th, '12, 13:25

theredbaron wrote:
Drax wrote:
theredbaron wrote:Q.E.D.
:roll:

Would you prefer if i would have used a more colloquial vernacular, such as maybe: "hey dude, are you blind or what, calling me illogical when a a few posts up you read about some other dude letting his tea rot in his cupboard sauna?"
Yes, actually, because QED is usually reserved for thorough proofs of theorems. You have pointed out one case of a problem among an unknown quantity.

I could give an example of somebody getting hit when they cross the street, and state that, therefore, nobody should ever cross a street. That's not QED. That's over-reacting.

Instead of over-reacting and condemning all cabinet-type storage, perhaps we can learn something from this particular blogger. For example, perhaps it's not such a good idea to have large, open vats of water near your tea? And perhaps it's not such a good idea to make it a sealed, stagnant environment (going back to your air-flow concerns)? It's a shame that said blogger hasn't updated in over two years. It would be interesting to see how things have progressed.

Clearly I am biased here, however. So let me share with you my bias. I have been storing most of my pu'erh in a large cabinet for over four years at a humidity from 65-70%, and with the temperature variations of southern (and now northern) Virginia (basically 55F in the winter, and up to 90F in the summer -- I kept the AC vent closed in the room with the tea). The humidifier system are plastic bins with water, and chimney-style wicks with little fans (like you see on CPUs) that blow out the moisture; another interior fan helps circulate air inside -- and a digital hygrometer that controls when the fans turn on or not (thus limited the max humidity).

Is this setup actually helping me age my tea better than if they were just sitting in the room? I have no idea! It's definitely great as a storage unit, and it looks really nice. But so far, no mold. Now, perhaps one day, I will be reporting, with tears streaming down my face, that my pu'erh has all molded. Maybe! But that day is not today.

In the meantime, yes, mold is always a concern, and we should always be on the watch.

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Re: Regarding long term storage

by theredbaron » Nov 11th, '12, 13:59

Drax wrote:
theredbaron wrote:
Drax wrote: Yes, actually, because QED is usually reserved for thorough proofs of theorems. You have pointed out one case of a problem among an unknown quantity.





In the meantime, yes, mold is always a concern, and we should always be on the watch.

And that was my point from the start - it is dangerous, it can happen, it has happened. And it will happen again.

It happened to the blogger, it happened to me (in a sense), and i have sampled many teas which may not have been covered in mold, but which have been stored in too much humidity and which turned rather musky, and which i would not call well aged teas, by any means.

Maybe your more sophisticated set up is safer, maybe not. You have stated that you have stored your tea for 4 years, and don't know if has aged the tea better than if you would have just let it sit in the room? Now you lost me. Have you not tried your tea? After 4 years there is already considerable change to notice, if stored in a humid climate. If you try tea that has been aged in Kunming, for example, you see very little change, as it would be if it would have been just sitting in your room.

I have neither advised to simply let your tea sit in the room in a dry climate, but that it is quite possibly safer to raise the whole room humidity by simply putting a room humidifier in your room.

http://en.wikipedia.org/wiki/Humidifier

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