How long will Tie Guan Yin stay fresh? How does it age?

Ever since people realized that people were making a great deal of money on aged puerh tea there has been a movement to age other teas. While I am not saying that no oolong has been successfully aged it is not like aging puerh and I do not think that it has virtually no limit on how long you age it like puerh. I think maybe you can age certain oolongs for a few years. But I do not think it is as simple as putting it away in a jar and letting it sit. I think usually aged oolongs are roasted oolongs and are reroasted every year for the aging process. Liquid Proust could tell you more about aged oolongs.

Green oolongs will only go stale if you try to age them. Oolongs need to be roasted and re-roasted periodically to age successfully.

Ive been told even a few months can impair the flavour of jade oolongs, hence why they are sealed.

Mine dont seem to last much longer than that anyway, I buy in smaller batches & wait for the seasons to come back round again. I have noticed them not tasting quite the same after 6 months compared to my notes when fresh

The more roasted the teas are the better they age. I’ve had green oolongs that are Ok after a year or two but they lost that something special. On the other hand, I had some Teavivre medium roast TGY that seemed good after a year and only lost a bit after two years. And some 2-4 year old dark roast that seem more or less the same (though not as interesting initially as the medium roast).

I’ve been trying intentionally aged oolongs as well, but haven’t had a lot of luck with them. A few good ones, but most are over-roasted and not all that great, and a couple were just terrible.

Wulongs do not age.
Aging is a factor of enzymes slowly metabolizing over time. Any tea that has gone under a sha qing (kill green step) does not have this factor. This is every tea besides sheng pu, whites, and reds. (Reds already have the enyzmes broken down so they dont need this step). Since wulong have had their greens killed, they do not age.

I think it’s a stretch to call something age when every now and then you reroast something, I.E. change the flavor. The tea its self is not developing new flavors, like an aged sheng pu might, it is just mellowing out. This should more correctly be called rested teas.

I tried a 40 year old Tie Kuan Yin this year at a Chinatown shop, in Bangkok, where I live. It tasted unusual, a bit like coffee, beyond that just different, not easy to describe. I compared two other aged oolongs from Taiwan and Thailand that were around 20 and 30 years old and they’d been affected much differently by aging. The 20-year-old Thai version was quite pleasant, picking up a plummy sort of taste that seems typical of aged oolongs, per what I’ve heard of those. The tea from Taiwan was musty as could be, and after that wore off it was ok, but still a bit odd.

It’s my understanding that the bright green lightly oxidized oolongs aren’t well suited for aging, that more oxidized and roasted versions are suitable. If the changes are positive at all would relate to personal preference. It’s commonly expressed that heavily roasted oolongs loose some “char” effect over a year or two so these are most suitable for at least limited aging. The rest is even more hazy, and whatever I would add is just hearsay, but I’ll add it anyway.

I’ve heard that properly sealed oolongs don’t need re-roasting, but that practice isn’t uncommon either, seemingly related to removing moisture that wouldn’t be in the tea if it could have been sealed better. It seems best to not confuse aging, fermenting, and oxidizing. Aging is non-specific; it can relate to any changes that occur over time. Fermenting is used to designate changes caused by bacteria and fungus, often linked to processing differences and enzymes being present, and also affected by environmental factors, exposure to air and humidity, temperature, etc. It seems fair to say that oolongs don’t ferment in the same way pu’er can, but the background is probably not so simple. Teas do keep oxidizing over time, given contact with oxygen, but that’s not as simple as the simplest descriptions let on either. In that shop where I tried the old TKY they had been drinking a very old Longjing once, which had blackened, but I can’t imagine it became anything like a black tea.

John is right on. I’ll add that with sufficient humidity and oxygen, oolongs will break down and age like pu erh with a very similar flavor profile. I’ve had aged roasted baozhong like that and it was just like shu pu erh.

Oolongs, when stored well, oxidize a little and offgas. There is some degradation/decomposition over time, and the taste definitely changes (and the effect, too, in many cases). I notice a cinnamon-like flavor in many good aged oolongs.

Great input Jay; that definitely leads to a lot of other questions that most people would keep to themselves. There is a sort of standard, in-the-background take that Dylan mentioned, that a difference in pu’er tea processing allows it to age and ferment differently than other teas. I’m not so sure about that; it seems possible, but I’m not clear on the difference. Per my understanding even sheng goes through a heating step and a drying step, both of which would kill the enzymes that kill-green / fixing steps in green tea and oolong processing kills to stop that initial oxidation process. Or is that wrong?

It’s hard to get a clear take on what fermentation is, for sheng pu’er, to judge to what extent it could or couldn’t apply to oolong. We just went through this in another thread, and I mentioned a good research paper-oriented reference about that, but it only discussed which bacteria and fungus were involved with fermentation. None of that covered the degree to which the same could apply for another tea type, or reviewed a role played by initially present enzymes. This line of questioning seems to apply most directly to white teas, beyond pu’er and oolongs, since aging of those is also common. It’s a bit redundant since we just went through that for a pu’er question but I’ll mention the post and link here, starting with a citation from the first source about pu’er processing:

Pu-erh tea has been made from C. sinensis var. assamica since the Tang dynasty (AD 618–906). There are two types: naturally fermented (raw) and purposely fermented (ripened) (Figure A in S1 File). For raw Pu-erh, the initial processing starts with natural withering of fresh tea leaves to initiate their drying, roasting of leaves to continue drying and denature plant enzymes, rolling the leaves to remove additional moisture, and, finally, complete the drying process through direct exposure to the sun 8. The dry, raw Pu-erh is then aged for varying periods to promote natural, solid substrate fermentation.

http://journals.plos.org/plosone/article?id=10.1371%2Fjournal.pone.0157847

http://teaintheancientworld.blogspot.com/2016/09/puer-storage-and-fermentation.html