Oolong grown on Taiwan's Alishan mountains, then put through an unusual step: fermentation in a high-nitrogen, oxygen-free chamber that converts the leaf's natural glutamate into gamma-aminobutyric acid, or GABA. The leaves are picked in spring and autumn from the same cool-climate, fertile-soil growing regions that produce Taiwan's better-known high-mountain oolongs.
The method traces back to Japan in the 1980s, where Dr. Tsushida Tojiro and colleagues at the National Institute of Tea Science were investigating ways to raise the levels of naturally occurring compounds in tea. They found that fermenting leaves without oxygen, in a nitrogen-rich environment, sharply increased GABA content. The technique was first applied to Japanese green teas and caught on for its relaxing reputation; Taiwanese producers, already known for their oolong, later adapted and refined the process for their high-mountain leaf, grafting a modern Japanese innovation onto an older Taiwanese craft.
In the cup, expect a smooth, rich body with earthy, woody undertones edged with something almost coffee-like, and a warm aroma carrying a hint of sweetness. The first sip is mellow, opening into ripe fruit notes reminiscent of apricot, with a touch of floral lift and a silky, lingering sweetness on the finish. Drunk plain, the fruit and floral character comes through most clearly; a little honey or a slice of lemon makes for a fair variation if you'd rather.
Brew it with water cooled to 80-90°C rather than a full boil, using about a teaspoon of leaf per cup, and steep for two to three minutes. Kept in an airtight container away from light, moisture and strong odours, the leaf holds its character well. This particular batch is sold by The Kent and Sussex Tea and Coffee Company. GABA itself has long been used in traditional contexts for its calming qualities, associated with easier focus, steadier sleep, and general relaxation — worth taking as folk wisdom rather than established fact.
