mao cha vs beeng cha

[gingkoseto]

but I'm not 100% sure that "fermentation" is such a clear-cut term.

In any event, I try to use "oxidation" when I mean oxidation.

Chemically speaking, fermentation is a form of oxidation - anaerobic oxidation or oxidation that doesn't use oxygen. So if sticking to the science jargon, I feel calling both oxidation and fermentation "oxidation" is safe, although people usually specify it when they talk about each of them.

And as you said, the word for fermentation has its root in agricultural culture. The word in both Chinese (related to booze) and English (related to yeast) reflect it. So I feel we can't argue with a farmer about how to use the word

[gingkoseto]

gingkoseto, the example of that jingmai (although poor fermentation is a serious hazard for all smaller-leaf puerh--good leaf and good process is even more important) is why I don't do puerh made with aged maocha. Virtually all of them have a stereotypically "dark" and simplified taste.

"Simplified" is what I feel from my Jing Mai as well! But I would still collect one or two if they come to my way.

Puerh is made from a variety of decay processes. If steaming was all that, at the very least, the japanese greens would age. They don't.

Actually I've been wondering about it for a while too. I have little knowledge of Japanese green but have wondered what's up with the aged gyokuro. I've got a box of 2010 Yunnan steamed green, which seem to last well through the two years. So I've been wondering if it's going to last well for a long time, or sort of "aging" with time being. But I don't think I'm enthusiastic enough to get more of it and conduct experiment. [/quote]

However...

http://mattchasblog.blogspot.com/2010/0 ... k-cha.html

This green tea does age after steaming. Therefore, as the post illustrates, caking allows for a higher quality kind of aging, and different shapes, with different processed leaf, ages differently.

I've seen a few Chinese "teachatters" reporting about their aged green tea, even including aged longjing (must be accidentally aged, instead of intentionally, I guess). Usually a lot of other Chinese tea drinkers would sneer at it and make fun of it. But if it doesn't cost much to keep the tea and then observe it, I would say, why not. Without trying, nobody can be sure what will happen. It's actually good to see things out of people's expectation.

[David R.]

Very interesting explanations and theories, thank you.

[Drax]

Wikipedia is your friend, or at least the first stop.

http://en.wikipedia.org/wiki/Tannins

As for enzymes..., think of them as running construction equipment, and BOOM, a leaf is bruised and the equipment escapes the construction site! OH NOs, the equipment is tearing chunks out of cars and buildings! A growing leaf using many enzymes to modify and place proteins where they are supposed to be. A few more specialized enzymes build chromatic complexes, aromatic chemicals, and stores carbohydrates created from the chlorophyl complexes. Lots of things happening, with many different enzymes doing different things. When we make hongcha or oolong, we're taking advantage of the destructive potential of various enzymes that are now out of place to create a certain mix of chemicals that pleases our noses and mouths when prepared properly.

Your link is good for learning what a tannin is. I asked for clarification on how a tannin is transformed, as was stated in the earlier definition, and more specifically, what was doing the transformation.

And out of morbid curiosity, could you please define "chromatic complexes?" I'm curious to hear what you think it means. I'm well-versed in the field, so please get as technical as you like.

[gingkoseto]

how a tannin is transformed, as was stated in the earlier definition, and more specifically, what was doing the transformation.

There are some Chinese studies showing that some microbes in puerh fermentation have tanninase to degrade some tannins into benzoic acid. Those microbes are some "typical" microbes in puerh, Aspergillus niger guys whose names give me a headache by just looking at them

Bezoic acid is responsible for the liquor color of aged puerh or shu puerh. It seems to have some potential health benefits. But I didn't see any mentioning whether tannin tannin degradation contributes to the flavor. The papers I glance through all switch to talking about other chemicals when they talk about flavors of puerh.

If organic chemistry doesn't make you dizzy as it makes me you may find some papers on PubMed about tannin degradation due to microbial tanninase activities (none of them is about puerh though). I only took a brief search and don't think I can bear with more of them but the microbial processes might be similar to those in puerh.

[Drax]

Thanks, gingko, one of these days when I have a lot more spare time, I'd love to read further into papers and books on this topic. I still have the book you gave me, but just haven't had a lot of time to explore it further.

From what I understood, that brownish-red color comes from the tannins (benzoic acid is itself a colorless solid), and the tannins also contribute to the astringency.

In any case, getting back to the original question of mao cha vs beeng -- is there a common pu'erh that is sold as both loose and compressed (from the same production)?

[TomVerlain]

in thinking that bings are "recipes", I would think there are no loose and compressed teas that are identical. (there being no mix of leaf grades in mao cha). I was also under the impression that mao cha was leaves before the whole compression process, which leaves them unchanged by the additonal steaming a cake or toucha gets.