Tuesday, June 28, 2011

Efficiency of partial storing 2

A: Opened almost every day
G: Not opened

A looked darker and greener, and G was brighter and brownish. It was not a huge difference but we found that A was slightly better in condition of appearance.

There was no big difference for brewed tea. However, we found G to give a poor flavor.

A had a darker color.

Prepared Tea A was also a little darker. Hiro and I both found A better than G. G tested bitter. The difference was more obvious on matcha than sencha.

This is a very surprising result. I expected that G would be better or at least we would not find much difference. However, the result is totally opposite. I have to say that A is better. I don’t find any good explanation about this but what I can only think that has caused it is moisture. It was rainy and very humid on the day when I packed these samples three weeks ago. So I think the moisture would have gone into the packages. This is only my assumption; by opening Package A every day, it helped reduce the moisture instead of gaining. G kept the moisture from the beginning and it made G worse than A. I think the two advantages of the parcel storing are avoiding oxidation and block humidity. If my guess is correct, you could say that the moisture has much worse impact than oxidation. Again this is just my assumption and nothing to be sure.

I’m dissatisfied with the result and I still believe the theory of the partial storing is correct. So I want to re-try this test sometime. I’m sorry that I could not give you any good advice from this test. But, why don’t you avoid opening a new package on a rainy day till I find out the cause. Jah!


  1. Hi Kohei,
    very interesting post! I agree with you and also think there is a high chance this was caused by humidity of air - from my experiences, I try to avoid opening new packs of tea on rainy days. Even though it may seem that if we are inside it's okay and the air is dry enough, tea is often more sensitive to outer factors than we can possibly imagine. Therefore, when we expose the leaves to such air and then move it into can (or any other storing device), seal it and won't open it in the near future, tea can be seriously damaged even by only a little humidity it got. After all, when it's in the can, it doesn't have any possible way to get rid of the moisture or, in other words, "breath it out" and it therefore starts to affect the tea faster.
    So, if you plan to repeat the test, definitely try storing the tea on a sunny warm day, I believe the result will be different. :-) If that won't work, than it seems like all my theories and beliefs about storage are wrong, haha!

  2. Hi, Michal-san,
    Thank you for your thought. I agree with you. I think I need to re-try this test on a dry day. Now I’m thinking to buy a hygrometer^^

  3. Hi Kohei, This is very interesting :) I'd also be interested in the daily storage in sakura bark caddys as they apparently help keep tea dry.

    Thanks for taking the time to make all your posts they're all very interesting and helpful!

  4. Hi Kohei,
    Very interesting post indeed. One thing that could have alleviated the humidity problem is a dessicant pouch. I always find one in new airtight containers. Altought it can be saturated in water (i.e. not efficient), it could be worth a try.
    Thank you for the post!

  5. Hi, Guillaume TR-san,

    Desiccants! That makes sense, but I have never thought about them for tea storing, or never heard that any tea shops recommend them in tea caddy? I wonder why. I’ve just done a quick search for “tea storing and desiccants” on the internet. I found that a few shops recommend them, but it seems that desiccants for tea storing are not so common in Japan. I really want to know the reason. I’ll ask some opinions at local teashops. Thank you for raising an interesting issue.