Caffeine in roasted vs. unroasted oolong?

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Jun 11th, '10, 23:58
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Caffeine in roasted vs. unroasted oolong?

by teashionista » Jun 11th, '10, 23:58

I know the topic of caffeine in different types of teas has been discussed several times here. But I couldn't find the answer to this: does roasting reduce levels of caffeine in oolong?
Since houjicha has significantly less caffeine than bancha (which is removed, I assume, by roasting), would the same theory apply to oolongs? I.e. would a heavily roasted TGY have less caffeine than its unadulterated sibling?

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Jun 12th, '10, 00:58
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Re: Caffeine in roasted vs. unroasted oolong?

by Chip » Jun 12th, '10, 00:58

That is an interesting question ...

I had read that it is more when green bancha is slowly roasted into bancha that its caffeine is reduced ... which I would then extrapulate that fast roasting would not.

So, perhaps the way it is roasted would also have some effect in oolong?

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Jun 17th, '10, 17:52
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Re: Caffeine in roasted vs. unroasted oolong?

by OchameTaiken » Jun 17th, '10, 17:52

Yes, indeed roasting is one of the factors that has a concrete effect on caffeine content.

Just as with the houjicha, oolong tea that is roasted or baked will also see a reduction in caffeine. When tea is roasted it gives off a bitter, white powder (guess what it is!) Mr. Kaiser from Rishi shared this photo of him in a tie guan yin roasting room. :lol:

When aged oolong is repeatedly baked periodically, it leaves behind more caffeine with each baking. So, if you assume all else equal between two like teas, the more roasted can be safely assumed to have less caffeine.
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Re: Caffeine in roasted vs. unroasted oolong?

by Chip » Jun 17th, '10, 18:08

Interesting, so this white powder just drops off the leaf during roasting? Somehow I just thought or assumed the caffeine was simply altered in roasting.

But, I honestly have no clue ...

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Re: Caffeine in roasted vs. unroasted oolong?

by teashionista » Jun 17th, '10, 20:04

Thanks for the info, OchameTaiken!

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Re: Caffeine in roasted vs. unroasted oolong?

by OchameTaiken » Jun 17th, '10, 22:29

Chip wrote:Interesting, so this white powder just drops off the leaf during roasting? Somehow I just thought or assumed the caffeine was simply altered in roasting.
Certainly some caffeine is actually liberated from the leaf. Granted the circumstances here are on a much larger scale, but you could try roasting your own green tea into houjicha at home, and see if you notice a little bit.

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Re: Caffeine in roasted vs. unroasted oolong?

by Chip » Jun 17th, '10, 22:34

Actually I do make my own Houjicha ...

I guess my point is, if the white powder is still on the leaf, the caffeine is still present in the brew?

It seems to me that something happens to the caffeine as in it is neutalized in the roasting. Either that or Houjicha and roasted oolong are not really that low in caffeine?

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Jun 21st, '10, 02:28
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Re: Caffeine in roasted vs. unroasted oolong?

by OchameTaiken » Jun 21st, '10, 02:28

Not affixed to the leaf. The caffeine is found left behind in the baking drum/oven. (Or dispersed in the air, as the case may be seen above!)

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Re: Caffeine in roasted vs. unroasted oolong?

by DJ3riple » Jun 21st, '10, 19:36

Cool, thanks for the info OchameTaiken :)
Last edited by DJ3riple on Mar 29th, '11, 02:12, edited 1 time in total.

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Re: Caffeine in roasted vs. unroasted oolong?

by Dresden » Jun 22nd, '10, 00:09

Now that you mention it, I did notice a small amount of white powder in the pan after home-firing some houjicha.

Interesting!

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