Wednesday, December 5, 2018

Storage Issues: “Shelf Fatigue”

Recently, James of TeaDB published an excellent article on storage comparisons.  He compared 3 of the same Yang Qing Hao cakes from different storage conditions.  One of his findings is something that is already well understood among puerh drinkers.  It’s something I refer to as “shelf fatigue”.

“Shelf Fatigue” refers to a cake that decreases in quality as it sits on the shelf waiting to be consumed, usually alone in a sealed plastic Ziploc/ Mylar bag or in the open air out of its regular storage conditions.  Many people will have some other more intricate storage system for larger qualities of puerh that is not always super easy or convenient to access but that keeps the puerh much better.  So for convenience, they bring a few cakes of puerh out of this deeper storage into a more accessible drinking storage set up close to their tea table.  The most common are in a tea caddy, ziplock/ mylar, or open shelf storage.

Of course, one way to prevent this in the first place is to limit how long your drinker puerh is exposed to shelf storage.   You can do this two ways.  The first way is to have less cakes available to drink at once.  For me I don’t like this option because I feel that “variety is the spice of life” and I commonly have 5 or 6 cakes going at once.  The second method is to just take smaller portions of puerh from the deeper storage.  This has its downside as well as it as it takes more time and energy to access my deeper stored puerh and it is pretty inconvenient for me.  Also, it exposes the deeper stored puerh to the natural climate on a more frequent basis which is not the purpose of most storage setups.

I have found that tea caddies are the best way to prevent shelf fatigue in puerh.  I remember trying experiments from teamasters in Korea using Korean ceramics comparing shelf, ceramic tea caddy (see some beauties here and here), and Ziplock bags.  The tea caddy was the clear winner in that climate and I believe it would also be a possible good solution in Western climates.  I think it’s also a beautiful esthetic that adds to the tea drinking experience.  The clay reconnects the qi of the leaf to the earth once again… So harmonious... Wilson also is a fan of the tea caddy for this purpose .

However, there are many practical considerations which prevents me from using this type of everyday/accessible storage.  First, is a space consideration, those caddies do take up a lot of surface space (x6) which I don’t have in my modest living space.  Second, is a price consideration, as these caddies can be a bit pricey.  The third consideration is that I keep the puerh on the cake and pry it off just before consuming it.  Others like to break up a whole cake or portion of a puerh cake for consumption, the caddy would be maybe better fit for them.  In the desolate climate I age puerh in nowadays, I am more uncertain about the benefits of a tea caddy.  This is the reason why I don’t own a large enough one to store puerh.  Some people in very very humid and warm climates might find open shelf storage adequate but most in the west will find this to be the worst for shelf fatigue.

I choose to go the route of the Ziplock/ Mylar bag.  This method works for the above reasons also because the sealed storage of the Ziplock works along with theory that sealed storage is superior.  However, shelf fatigue in this type of drinker storage is common as evidence by James’ findings.  I postulate that shelf fatigue of puerh is due to two possible factors. 

The first possible theory of shelf fatigue is that, with repeated opening and closing of the Ziplock/ Mylar, the puerh cake eventually loses moisture and dries out.  The dried out puerh tastes less dynamic compared to the more humidly stored puerh.  To remedy this, I have experimented with just wiping the plastic ziplock with a moist cloth or paper towel.  This seems to help a bit but I find it not as effective as using the steam from the kettle to add warm moisture to the bag.  I have experimented with actually holding the paper wrapped cakes over the steam at a distance as well, this works alright because really it is just the paper wrapping that gets hit with the steam but I have settled with steaming the bag instead these days.  I have been doing this for a few years now and think it is the most effective way of maintaining the puerh when in shelf storage.

I usually put my hand a few feet above the steam of the kettle so that the steam is not scalding and will not melt the plastic but is just warm.  Then I tip the bag on its side and let the steam collect in the Ziplock.  It will fog up the plastic. Then I press out the air and seal up the zipper seal on the bag.  Use caution here people, and air on the side of safety else you will get a steam burn or melt the plastic.  This technique adds both humidity and a touch of heat and doesn’t add any plastic smells if the steam is cool enough.

The second possible theory of shelf fatigue is that, as a puerh cake is consumed in a bag and the bing gets smaller and smaller, more surface area is exposed to air and less to other puerh.  The idea is that puerh tastes better when aged with other puerh.  To remedy this I suppose you could put the puerh in increasingly smaller Ziplock bags.  I tired that but didn’t notice as much difference in maintaining the puerh and it was a little annoying to me to have all these little baggies around.  What I do, and seems to work much better, is that when my puerh cake is about 1/3 to 1/4 consumed, I throw it in with a bunch of other puerh that are about 1/3 or more consumed.
I wonder if you have ever experienced shelf fatigue and I wonder what you do to remedy this storage issue? I hope these little tips help you in consuming better tasting puerh.  After all, what is the point of all the storage fuss if you end up consuming less optional puerh in the end?



marco said...

Nice to hear these real-life puerh experiences -- with my mind's eye, I see Mattcha steaming his bings, very vivid!

I have a drawer full of small ziploc mylar bags which I use to keep portions of my cakes in progress, so that I can leave the main cake alone in storage. Shelf fatigue is something I have definitely experienced, and for me I think it correlates with cakes/samples drying out or getting too cold. This is why I think it's very important how good the bag seal is. Most normal transparent ziploc bags do not seal well at all, and lose moisture very quickly. Thicker is also not necessarily better -- it's all about the actual seal. Test out your bag by sealing it and squeezing it -- put the seal up to your ear. If you can hear the hiss, and you're heating your home in winter, then you will have shelf fatigue :)

a bad pasty said...

I steam in the ziplock as well. Kinda assumed I was the only vagrant doing that :). Even went through the same progression of first steaming the cakes, then later just steaming inside the bags. I think breaking up and storing in a caddy may be prefferable, but ziplock steaming is easier.

Matt said...


Ensuring the Ziploc has a proper seal in the first place is something I don't always do- very good advice! I often check my older used ones or if I suspect holes or a bad seal but I rarely check new ones.

There is currently some discussion on Mylar bags in TeaDB's article I linked to here:

What bags would you recommend Marco?

A bad pasty,

Hahahaha.... awesome! I agree about the convenience of the Ziploc steaming.


Ho Go said...

Greeting Matt,

It's been years since I've posted on any blog and glad to see you are going full steam ahead. I see you've changed addresses since I last checked in.

Shelf fatigue is also exacerbated by the natural progression of a cake in its aging process. Sometimes my cakes go through a period of tastelessness which is very disconcerting. After some time, voila, as if by magic, the flavor profile resurrects and goes on to become what I'm hoping for. Of course, some cakes just don't age well.

I would never steam a cake and put it back in storage. Too dangerous in my neck of the woods. But I do use ziplocks for all my cakes. Hojo seems to have uncovered this technique of storage and it works very well here in SE Asia. I would be loathe to comment on it working the same way in western climates. So many different opinions on 'how to' floating around.

Good luck to all on finding the optimum way to store their cakes.

marco said...

I recommend the 1 gallon (for 1 or 2 cakes) 2 gallon (for 5-8 cakes depending, without tong shell) and 5gallon (for two tongs) 5mil thick bags with ziploc closure made by shieldpro/discountmylarbags -- they have a website and are available on ebay. In canada there is which also has excellent 5mil thick quality ziploc mylars. Cheers!

Matt said...

Ho Go,

I think you are referring to what is know as a “quiet period” in puerh aging. This is also well documented by puerh drinkers and is a bit different than shelf fatigue. But none the less, worth mentioning here.

Shelf fatigue more refers to puerh that is destined to be consumed and not put back into long term storage.

There are few blogger commentors that could bring about debate and insightful discussion here on MattCha’s blog better than you. Your commenting style has always acted as a meaningful counterpoint to my own- thanks for this.


Nice, should order soon.