Thursday, May 31, 2012

Aging Under Sealed Conditions

I ran across hojotea's minority view on pu-erh storage of which I have included the juicy bits below.  What hojotea is saying is ringing all sorts of bells in my head:

"We however think that pu-erh must be kept without oxygen. Therefore our tea is packed without oxygen even if we need to spend extra effort in packing. First of all, the primary reason why pu-erh tea is compressed is to ensure that there is no oxygen inside the tea leaves. Those ancient people in Yunnan has known that in order to get tea matured nicely, it is essential to remove oxygen. Similarly, Taiwan oolong is sometimes kept without oxygen. With this method, the original floral flavor of the high mountain oolong becomes a distinctive peachy flavor after being kept for 3-5 years. For pu-erh tea, the same theory is also feasible."

This goes against all expert advice which recommends the cakes need to breath to age- not too much but a modicum amount of airflow.  Experts also recommend putting beengs in airtight storage to stop further process of fermentation.

I tend to buy kimchi in vacuum sealed bags from Korea and I can tell you first hand serious fermentation continues to occur.  Actually if you have ever experienced an exploding jar of kimchi which was packed and sealed tight, you know what hojotea has to say is not untrue.  Bioactivity in pu-erh probably requires only thimblefuls of air.  I feel this could be a way for me to beat the low humidity in Berkeley.  I'd somehow have to wait until it's about 60% humidity when the cakes are at an ideal level, then put them in airtight heat sealed mylar bags maybe using nitrogen preservation.  Well, I had better just start with the used resealable mylar bags I have for my other teas.

Following hojotea's argument, storing shengs in airtight packaging with sufficient moisture should solve the lack of ambient humidity no?   I must experiment for myself but if anyone has any experimental results already, please let me know.


  1. My friend in Beijing stores tea in plastic bins using a double bag method - the inner bag (plastic or some other water repellent substance) holds the tea, and a little water is sprinkled in the space between the inner and outer bag. Bags are kept open, while the bin is shut close. This seems to keep moisture sufficiently high. It's a lot of work and there's always a risk of spills.

  2. I have been religiously replacing a bowl of water on the tea shelf after I read your tip when you were living in Beijing. The bowl definitely puts the humidity a few notches but I guess it's not enough for triggering aging- just stops reverse aging... Your friend's setup scares me- always the potential for mold if you are not paying attention. I'd rather risk slow over ruin.

  3. Exciting Blog hster. Agreed with MarshalN. Living in drying area, the double bag method is always a good start. As long as you let the tea breath every spring time for a month so to 'soak up' enough spring moisture and 'wake-up' from hibernation.

    Open air storages are just for eager vendors or noobs with no patience. ~ Toki

    1. Toki,

      So good to see you! A few months ago when I tried to return to my favorite tea haunts, I saw that chadao had gone sadly silent and I wondered where the old gang had gone.

      I still have your vacuum sealed tea from the Live Journal tasting unopened- I'm saving that treasure for at least 2016 to test aging under sealed conditions.


      (I just finally figured out that Toki=토끼. That would be two 꿀 밤 for my denseness. I had assumed Toki was Japanese.)