This tea was invented in the 1980s by Japanese researcher Tsushida Tojiro during his studies and experiments with various food preservation techniques. Since then, the technology for making GABA tea has been perfected in Taiwan and it is now also the main producer globally with production being almost entirely in the ball-rolled oolong style.
Natural chemical compound
GABA stands for gamma-Aminobutyric acid. Found naturally in mammals, this amino acid is the primary inhibitory neurotransmitter in the central nervous system and understood to help regulate excitability, stress and anxiety, as well as lower blood pressure and aid sleep quality. In more simple terms, GABA acts like the brakes of the brain helping it move into lower gear. Working in tandem with excitatory neurotransmitters, such as glutamate, it ensures the body’s physical and psychological homeostasis.
Production process for GABA tea
The production process for GABA tea has two crucial steps responsible for the elevated levels of this compound. First, prior to harvest, tea bushes will often be shade-covered for a period of 10-14 days. This helps boost the amount of glutamic acid in the tea leaves, a naturally occurring chemical and precursor to GABA. Second, following the outdoor and indoor withering stages, the tea leaves are loaded into steel tanks, oxygen vacuumed out and nitrogen flushed in, and then kept at a temperature of over 40°C for 8-10 hours. This process is usually repeated three times and it is during this step that glutamic acid is converted into GABA.
Going into a bit more detail specific to the making of Taiwanese GABA oolongs. In between keeping the tea leaves in steel tanks, they will be transferred into cylindrical bamboo tumblers for 3-4 hours. This alternating between anaerobic and aerobic conditions is said to increase the amount of catechins known as gallate esters and therefore enhance the aromatic qualities of the finished product. Finally, following the kill-green, rolling and drying stages, Taiwanese GABA oolongs are also often roasted and then left to settle for a period of 2-4 weeks in order to even out the flavour profile across the batch.
Although most GABA tea sold on the market is oolong, we should mention that green and black GABA teas are also produced. Strictly speaking, the only condition that needs to be satisfied in order to qualify as a GABA tea is that concentrations of this compound exceed 150mg per 100g of dry leaf. By way of comparison, this is approximately 25-30 times more than in conventionally processed teas.
Disclaimer re: health benefits
Despite the anecdotal evidence of various health benefits associated with drinking GABA tea, it is important to note that there currently is no scientific consensus as to whether exogenous GABA can cross the blood-brain barrier and therefore its effectiveness as a dietary supplement is still debated.
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What's next?
Want to be your own judge of whether GABA tea makes you feel any different? Our Jia Ye Long is a classic high-mountain oolong from the Alishan area, but processed according to GABA methodology and then finished off with a single light roast.
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