What is GABA tea?

Standing before my cupboard, I spy an unopened packet, an Assam GABA tea (Tailor Made Teas) I got from a tea swap I did a few months ago. I have not had it before but it came with the promise of a story, and that was enough.

My starting brew for any tea is almost always the same: 2-3g ( 1-2 tsp) of leaves, boiling water, steeping time of 3-4 minutes. Based on how this tastes, I make any further adjustments—more tea, longer or shorter steeping times or water temperature. This has always worked for me, unless it’s a green tea, which needs less steeping time and lower water temp. I brewed the GABA Assam oolong in my usual way. As oolong, it is semi-fermented but had dark well rolled leaves. But the flavours reminded me of a yellow tea, nutty/grassy flavours. It was smooth and enjoyable.

GABA is an acronym for gamma-aminobutyric acid, an inhibitory neurotransmitter which is said to have a calming effect. It’s also found in tomatoes, potatoes and some citrus fruit. Given that, it’s surprising how under-sold this tea is, seeing its entire premise is based on its amino acid levels, a natural fit for the growing wellness beverage space.

In the mid 1980s, while researching the ways to make green tea more “functional” or basically accentuate its beneficial properties, Prof. Tojiro Tsushida and Prof. Toshinobu Murai of the Japanese National Institute of Advanced Food Research stumbled upon a peculiar development. While researching L-theanine, one of tea’s most celebrated antioxidants, they discovered that when the tea leaves were exposed to nitrogen before steaming (Japanese green teas use steaming to arrest oxidation as opposed to roasting in the Chinese style), the production of gamma-aminobutyric acid increased. And so a new style of processing was born, named gabaron tea, in Japan.

A later study (2022) from Tokyo University of Agriculture, builds on it, with an additional step to offset the “offensive odour” that the fermentation produced. By Japanese standards, for a tea to qualify as a GABA tea, it should have 150mg GABA per 100g of tea.

In the decades that followed the discovery of GABA tea, Taiwanese tea producers took this style and processing methods to apply to their own teas. While the process can be applied to green, black or the oolong, the Taiwanese oolong and Ruby Black tea have been especially favoured to make this style of tea, where the extended fermentation and later roasting, took care of the above-mentioned offensive odour.

Still, here’s the thing: there simply aren’t sufficient studies to back the health claims it comes with.

The GABA tea seems to have pockets of loyal fans, but it’s precisely the sort of thing the wider industry should be paying attention to and investing in more research to substantiate the tea’s nutritional aspects. That’s one more way to bring more tea to people. The GABA may not find the cult following matcha has now, but as tea, it’s well deserving of a second cup.

1001 Teas is a fortnightly series about the many stories hidden in the world of tea. Aravinda Anantharaman (@AravindaAnanth1) is a tea drinker, writer and editor.