Country
Thailand
Thai tea comes almost entirely from the far northern hills, and it holds two traditions that have nothing to do with each other. One is an oolong industry built by Chinese diaspora communities and Taiwanese technique, making rolled oolong that can pass for Taiwanese because it is made from Taiwanese cultivars in the Taiwanese way. The other is miang, an indigenous fermented tea from wild forest trees that is chewed rather than brewed.
What grows here
Rolled oolong is the export product, principally from Doi Mae Salong and Wawee in Chiang Rai, with green and black teas made alongside it. Miang is the older and more local tradition, made across the northern hills from mature leaf off large forest trees. Some producers also make green and sun-dried teas from those same old assamica trees, aimed at buyers who recognise the material from Yunnan.
The ground
The northern highlands of Chiang Rai and Chiang Mai, roughly 800 to 1,600 m, are the same mountain system that continues into Shan State and southern Yunnan, which is why the same wild tea trees grow on all three sides of the border. The planted oolong gardens sit on cleared upper slopes; the miang trees grow in standing forest, often on land that has been harvested rather than farmed for generations.
The bushes
Two entirely separate populations. The forest trees are native assamica-type, seed-grown, old and locally variable, the same broad-leaf plant that Yunnan works with. The plantations are an import: Jin Xuan, Si Ji Chun and Ruan Zhi, the soft-stem type Taiwan usually calls Qing Xin, brought from Taiwan along with the equipment and the processing knowledge. Thai sellers often write Ruan Zhi as 'No. 17', which is not a Taiwanese cultivar number: Tai Cha 17 is Bailu, and Ruan Zhi is an old Fujianese landrace that was never numbered. Worth knowing before buying, since a Thai oolong is not a distinct varietal tradition so much as a Taiwanese one relocated south.
Harvest seasons
The latitude allows picking through most of the year on the plantations, which is part of why Thai oolong is cheap. Cool-season lots are the ones to prefer, for the usual reason that slower growth gives denser leaf. Miang follows a different logic entirely, taken from mature leaf rather than young shoots, so its harvest is not organised around a spring flush at all.
How it is made here
The plantations run the Taiwanese sequence: withering, a tossing-and-resting oxidation, kill-green and repeated cloth-bag rolling into pellets. Miang is the genuinely local craft. Mature leaves are steamed and then packed tight into bundles and left to ferment anaerobically for weeks or longer, producing a sour, savoury leaf that is chewed with salt rather than infused. It is one of the few surviving traditions where tea is eaten rather than drunk.
What to look for
The mislabelling here runs the opposite way to most places: Thai oolong turns up sold as Taiwanese, which means a Thai oolong bought honestly is often the better value of the two. Do not expect a distinctively Thai character from it, since the cultivar and the method are imported. For teas sold as wild or ancient Thai assamica, treat the age claim as you would in Yunnan, and note that miang leaf and brewing-grade leaf are different products from the same trees.
How it got here
The oolong industry has an unusual origin: Doi Mae Salong was settled by remnants of Chinese Nationalist forces who left Yunnan after 1949 and were eventually resettled in northern Thailand, and their descendants brought Chinese and later Taiwanese tea knowledge with them. Royal development projects from the 1970s onward promoted tea as a substitute crop for opium poppy in the same hills, which is how much of the planted area came to exist. Miang predates all of it by centuries.
Places in Thailand
Named places inside Thailand. The ones with a page of their own are links.