The greening of gongfu

It's a really good question, one I've thought about too. Although I don't drink many green oolongs there have been times when an oolong I thought to be medium roasted and quite brown comes out a fairly verdant green at the end. The only two theories I had ever come up with in my mind were that either the oxidation/roasting was just very superficial and "wore off" during the repeated brewings or that the heating of the leaf somehow rejuvenates the leaf to become slightly green again.

Those two theories are about as scientific as my socks, though, so I'm sure one of the proper scientists will have the real story... I hope, because I'd like to know too.

- Dominic

Lew I've also noticed the same thing and wondered as well how something so brown could turn so green. I've found this happens for medium oxidized and/or medium roasted teas. For very roasted teas they usually stay pretty dark. I was wondering if the oxidized portion of the leaf is more water soluble since the liquor does turn brown. Hopefully someone will have a more scientific explanation.

My guess the depletion of chylophyll. Oxidation reduces chylophyll. I judge a green tea from the color of the spent leaf. Indian oolongs are essentially black. Chinese oolongs are essentially green.

Jim

Lewis Per> For quite a while I've noticed that for lots of teas (e.g. young raw

On Jun 27, 3:56 pm, TokyoB snipped-for-privacy@gmail.com wrote in response to Lew's question:

Here is a guess rather than an explanation, which would require a lab assay. Chlorophyll is insoluble in water (ref. Wikipedia, also my experience with cooking). So I don't suppose that the brown turns green but that the brown pigments are soluble, leach out, and leave only chlorophyll as a pigment. I note that most bright green tea leaves don't yield a green liquor. Now if you brew your tea in hot oil your results may be different.

Best,

Rick.

That makes sense to me as far as it goes. I think the red/brown water-soluble pigments would be thearubigens and theaflavins. But how would the green chlorophyll be either browned or masked in teas like reds/blacks and cooked and aged raw Pu'er?

/Lew