GABA and related tea processing, what is it
It was discovered some time ago that by restricting air contact with tea during processing it is possible to increase the content of a chemical compound that helps regulate brain function, GABA (gamma-aminobutryic acid). On-line research turned up an old blog post by the Tea Nerd that goes into this compound background a bit more than I intend to, and Wikipedia goes into brain chemistry even further.
GABA synapse receptor model (source: Wikipedia)
Another immediate concern might be the effect of the processing, how it works, and how it changes the tea. In discussing this with an on-line tea acquaintance Michael Coffey commented:
"my understanding is that during the oxidation process, oxygen is the preferred compound to bind with in various chemical interactions, but if oxygen is replaced with nitrogen, then the reaction has no "choice" but to use nitrogen instead of oxygen. So it's not the absence of air, but essentially forcing certain chemical reactions that wouldn't end up happening if oxygen were present."
So essentially the tea is processed similarly to the normal methods, but in contact with nitrogen instead of air. Since nitrogen is the primary component in air the end effect is a greater change than one might initially expect. The process makes you question "oxidation level" as one of the main standard descriptions of this tea, a subject I'll revisit. More could be said about these concepts but for now I'll skip ahead to how the actually tea tastes.
Alishan Gaba Oolong tasting:
I obtained the tea from the May Zest Tea Company in Taiwan, a local supplier of a number of specialty teas from there. This link goes to the product description, which focuses on both the effect and the unconventional taste of the tea. Note this supplier usually deals in higher tea quantities than retail sales amounts, but they were very kind about supplying tasting sample quantities instead.
Alishan GABA oolong (source: May Zest)
The Tea Nerd blog post mentioned earlier described that other reviewed tea as very sweet, fruity, a bit one-dimensional, with an unusual mouth-feel, so quite different. These teas struck me as earthy, with an unusual taste element similar to malt, yeast, or even cork. It brewed to a brownish red color of tea, not a pale yellow or gold.
The main flavor of the tea was not bad, interesting, perhaps hard to appreciate for being so unconventional. "Malt" elements are a current favorite of mine but I've not experienced them paired with this type of background, and often teas that exemplify such flavors are unusually complex, not so simple in flavor profile. The taste of the tea was consistent throughout both the process of tasting it (initial flavor, finish, all taste elements just that one limited set--see last blog about related taste methods), and consistent across infusions, maybe with the earthy "cork" aspect fading a little as the malt picked up later.
One other side-note raises a sensitive subject: I tried a little of the tea with sugar in it. Most typically that would make sense for cutting the effect of astringency in tea, and there was essentially none in these teas, or maybe just for a taster hooked on sweetness, which I'm not. A little more sweetness did improve the tea by allowing those unusual flavors to make slightly more sense, in a way that an example might help illustrate.
Once on a family restaurant outing to a Mongolian grill place my niece and I both erred in adding too much spicing to the ingredients. During cooking you add seasoning over time, tasting in the middle, but it's harder to guess it out into a bowl at the outset. We tried adding salt to the dish later, which couldn't possibly affect the spice or "heat" level, but the taste made more sense when balanced with more of another flavor element. In a similar way a little more sweetness seemed to make the unusual taste of tea balance better, although I still drank most of it unsweetened out of habit.
tea effect; does it "work"?
I'm really not the right person to gauge this. I drink tea for taste, and can notice it contains caffeine that isn't as jarring as from drinking coffee, but beyond that I really don't pick up the different "qi" effects some people describe. Of course I accept that there are other effective compounds in tea, so real aspects are being described; I just can't judge them in myself. I'm not sleeping well these days in general--my daughter is 7 weeks old--so I'm probably even less tuned in to being relaxed or sleepy just now, always a bit groggy.
I noticed no difference from the normal effects of tea, but then I accept that some of the other conventional calming effects related to various active compounds are valid and I'm just not sensitive enough to notice them. It is possible the compound in these teas could enhance relaxation, or it really may not.
various types of GABA processed tea
The different grades of the tea were noticeably different but only moderately so. The one described flavor element was consistent and dominated the teas, so variations in body and complexity were minor. This may be one case where a drinking lower grade of tea makes sense since anyone drinking the tea would be likely be doing so for the effect, or perhaps for a preference for the taste element common to the various grades.
As I drink tea primarily for taste even though I like teas with some similarity the limitations of the tea offset that (slight "sourness," lack of complexity, unusual tea body). It would seem most would try the tea for the effect, which may or may not actually occur due to this additional compound. As the Tea Nerd blog post pointed out, "L-theanine causes the brain to produce more GABA itself." So the most active calming effects of these teas could be tied to a compound that is much more familiar and universal.