How Does an Oolong Age?

[Maitre_Tea]

I know that there have been many topics addressing this, so please forgive me if I'm asking the same questions that have already been answered in a previous thread. I've poked around but have yet to find a "satisfactory" answer...

So with this preemptive apology for the possibility of wasting somebody's time, my question: what exactly causes an oolong to age?

We know, generally speaking, that pu-erh aging is a mixture of microbial activity, cell-break down, and other mysterious psuedo-science mystical voodoo. But what about in oolongs? There aren't any microbes that are intentionally added like in pu-erh, and aging oolongs usually takes place in more airtight conditions than with pu-erh. Is it just cell walls breaking down naturally over a really long period of time?

Related to that point, it's been established that high fired teas usually age well, and we have examples of aged high fired TGY, Shui Xian, Tie Luo Han, etc. but what role would oxidation levels play in the aging potential in oolong? I've read that higher oxidation levels are good for aging, and I think it was written in Hou De's blog about the Hong Shui Oolong.

Thoughts, anyone?

[AdamMY]

I had it explained to me whereas the puerh flavor changes in very major ways, I hear oolongs or at least high fired oolongs change only slightly but it is for a more complete flavor profile and most people find it to be a better taste.

But I think its the breaking down of cell walls slightly over time, but limited microb activity.

[Zanaspus]

I have no idea of the chemical mechanism. I just know it happens, and I love it.

[gingkoseto]

I can understand how some roasted oolongs "rest" from a few months to a few years, when they "fade fire" (my non-scientific interpretation: some smoky stuff from roasting evaporates, hence allow the best roasted flavors stand out; leaves absorb little bit of moisture and not as super-dry as newly roasted).

But I don't understand how oolong ages beyond a few years. I have a some teas that I believe they will last well in future several years. But whether they can be further sublimed by time, I very much doubt it.

In some Chinese provinces, aged oolong (>3 years) was traditionally used as herbal medicine because it retains many health benefits of tea but is generally milder (oxidation and reduced tea polyphenols). But at this stage, the oolong was regarded as more of an herbal medicine than an epicure beverage.

[Maitre_Tea]

it seems like this has even more mystery behind it than the mystery behind the aging of pu-erh

[gingkoseto]

Related to that point, it's been established that high fired teas usually age well, and we have examples of aged high fired TGY, Shui Xian, Tie Luo Han, etc.

I guess this really depends on what time scale "aging" means. I don't think aging oolong (especially for more than a few years) is ever a popular idea in mainland China (so far, not sure about future ). Some tea farmers in Fujian keep small amount of 3-30 years aged tea at home but it's never a hype in market. Aging oolong seems to be discussed more among Taiwan tea professionals, but I got the impression that even in Taiwan it's not a prevailing idea.

[ABx]

I don't know for sure, but I suspect that it's just oxidation. Wulong will turn into something quite like puerh if it's stored in open air (i.e., if it gets too much moisture), but kept sealed and/or re-roasted to get rid of excess moisture it seems to take on some characteristics of mild oxidation. That's really purely a guess, though (and I personally doubt that microbes really play much role in aging puerh, although it's possible that some enzymes may be involved).