Taiwan Ruby #18 (Hong Yu)
Taiwan Ruby #18 (Hong Yu, red jade) is a named-cultivar black from around Sun Moon Lake in Nantou, a 1999 release crossing Burmese large-leaf assamica with a native Taiwanese wild tea. Its signature is unmistakable: a natural cooling menthol-and-cinnamon aroma over a smooth, sweet, low-astringency black. It is one of the most distinctive blacks in the world and Taiwan's flagship hongcha.
Long, dark, wiry leaves; the real giveaway is the aroma, a natural minty-wintergreen and cinnamon-spice character with no astringency. The cup is smooth, sweet, and full with that cooling finish. Sun Moon Lake (Yuchi) origin is the benchmark, and the cultivar is grown elsewhere in Taiwan with a slightly milder expression. Be wary of blends that cut Ruby 18 with cheaper black to stretch the aroma.
TRES cultivar number 18, bred by Taiwan's Tea Research and Extension Station and released in 1999, crossing Burmese Assam with a native Taiwanese wild tea (Camellia formosensis). The Sun Moon Lake area in Nantou is the historic and benchmark growing region, where black tea was developed during the Japanese colonial era. Related cultivars include Ruby 21 and older Assam plantings, but number 18's menthol-cinnamon signature is its own.
Western: 90-95°C, 3 g per 200 ml, 3 minutes. Gongfu: 4-5 g per 100 ml, 90°C, 15-20 seconds ascending, 6-8 infusions; the aroma holds across many steeps. Drunk plain, because milk masks the cultivar's whole point.
Solid Ruby 18 runs €15-40 (about $16-43) per 100 g. Traceable Sun Moon Lake estate lots reach €40-80 (about $43-86) per 100 g.
Prices reviewed June 2026
Dianhong (Yunnan)
Another assamica-derived black, but malt-and-honey rather than menthol-and-cinnamon.
Taiwan Black Tea (Hong Cha)
The broader Taiwanese black category this cultivar sits at the top of.
Oriental Beauty
Taiwan's other signature export, an oolong, for contrast in how the island builds natural aroma into a leaf.
Keemun
A small-leaf aromatic Chinese black, opposite in leaf size and in the source of its fragrance.
The menthol-wintergreen and cinnamon aromas of Ruby 18 are inherited from its native Taiwanese wild-tea parent and are entirely natural. The cultivar was bred specifically to express them, making it one of the few black teas whose signature scent is a genetic trait rather than a processing or scenting effect.