Topic: Tea Continues to darken after the tea leaves are removed.

Hello there,

I am pretty new to the world of tea and so far I am in love with it.

I have noticed that even after I remove the leaves the color of the tea continues to darken. I have googled the subject and have come up with no answers. Does anyone know why?

Thanks so much.

Re: Tea Continues to darken after the tea leaves are removed.

breathin1982 wrote:

I am pretty new to the world of tea and so far I am in love with it.

I have noticed that even after I remove the leaves the color of the tea continues to darken. I have googled the subject and have come up with no answers. Does anyone know why?

Can you explain what you're seeing again a little better? I'm not quite sure I understand the question.
If you mean why does the color of the brewed tea change when the leaves are no longer in it, well, it doesn't.

Re: Tea Continues to darken after the tea leaves are removed.

william wrote:
breathin1982 wrote:

I am pretty new to the world of tea and so far I am in love with it.

I have noticed that even after I remove the leaves the color of the tea continues to darken. I have googled the subject and have come up with no answers. Does anyone know why?

Can you explain what you're seeing again a little better? I'm not quite sure I understand the question.
If you mean why does the color of the brewed tea change when the leaves are no longer in it, well, it doesn't.

Does too!  (Sometimes, at least.)  I've noticed this from time to time if I leave a cup of tea undrunk for 10-15 minutes.  Certainly when you separate the leaves from the liquor there's still water, heat, and hundreds of chemical compounds, so it doesn't seem strange to me that something could be happening to change the color of the liquor.  But what is it? - I've no clue.

/Lew
---
Lew Perin | perin@acm.org | http://www.panix.com/~perin/babelcarp.html

Re: Tea Continues to darken after the tea leaves are removed.

Isn't that oxidation? Any good de-oxidant can be oxidized fairly fast themselves. I didn't notice the darkening happening as fast as breathin1982 describes, but for tea water (without leaves in) sitting over night, I've seen some tea (not some others though) water changed into dark brown. As I remember, almost everyone with this phenomenon is Taiwan greener style oolong. I wonder if it's because in the very green style oolong, the enzyme is not really killed.

門前塵土三千丈,不到薰爐茗碗旁

Re: Tea Continues to darken after the tea leaves are removed.

If you really want to see it, leave a cup of sencha around for a few hours. It will turn from yellow or green to brown.

Re: Tea Continues to darken after the tea leaves are removed.

I have heard different versions:
1) Oxidization of Theophyllines in tea causes color to change.
2) Oxidization of catechins in tea causes color to change.
3) Personally, I think both are right.

Re: Tea Continues to darken after the tea leaves are removed.

Let's not forget that there are still tiny leaf particles in your brew that have slipped through the filter. This is especially true with choppy sencha.

Re: Tea Continues to darken after the tea leaves are removed.

kingstonlam wrote:

I have heard different versions:
1) Oxidization of Theophyllines in tea causes color to change.
2) Oxidization of catechins in tea causes color to change.
3) Personally, I think both are right.

Third answer is correct, I think as well.

Re: Tea Continues to darken after the tea leaves are removed.

kingstonlam wrote:

I have heard different versions:
1) Oxidization of Theophyllines in tea causes color to change.
2) Oxidization of catechins in tea causes color to change.
3) Personally, I think both are right.

I agree, it must be the oxidation of some of the compounds in tea. I guess you could test this by brewing two control infusions, then sealing one in a bag and keeping another exposed to open air.