GABA Oolong
GABA oolong is a modern oolong processed under nitrogen instead of oxygen, which converts the leaf's glutamic acid into gamma-aminobutyric acid (GABA), the compound it is named and marketed for. The anaerobic step also reshapes the flavor, pushing toward a distinctive tangy, dried-fruit, caramel-and-sour-cherry character quite unlike a conventional oolong. To carry the name it must contain at least 150 mg of GABA per 100 g.
Usually a rolled, semiball oolong similar in appearance to other Taiwanese oolongs; the giveaway is in the cup, a tangy, sour-sweet, dried-fruit and caramel profile rather than clean florals. A stated GABA content (the 150 mg per 100 g threshold or higher) on the label indicates genuine anaerobic processing. The distinctive tangy note is intrinsic to the method, so a completely conventional oolong flavor suggests the GABA processing was minimal.
The nitrogen-processing technique was developed by Japanese researchers in the late 1980s and was adopted and popularized in Taiwan, now the main source of GABA oolong. It is a processing category rather than a region or cultivar, so it can be made from various oolong base leaves at different oxidation and roast levels. The health framing, GABA as a relaxation and blood-pressure aid, drives much of its marketing.
Gongfu: 6-7 g per 100 ml, 95-100°C, 30-45 seconds ascending, 6-8 infusions. Western: 4 g per 250 ml, 95°C, 2-3 minutes. Brewed like any rolled oolong, with the tangy character most pronounced in the early steeps.
GABA oolong runs €15-40 (about $16-43) per 100 g, with premium high-mountain or carefully made lots reaching €40-70 (about $43-76) per 100 g.
Prices reviewed June 2026
Ali Shan
A conventional high-mountain oolong, useful for tasting exactly what the anaerobic processing changes.
Dong Ding
A roasted oolong, another route by which the base leaf is transformed after picking.
Oriental Beauty
Another oolong defined by an unusual transformation, insect bites rather than nitrogen processing.
GABA tea was discovered as a byproduct of research into food preservation under nitrogen, when scientists found the anaerobic treatment dramatically raised the leaf's gamma-aminobutyric acid content. The 150 mg per 100 g figure is the conventional minimum used to label a tea as GABA, and the actual content varies considerably between producers.