Camellia sinensis Seeds | Tuo Tea
LATIN NAME: Camellia sinensis
COMMON NAME: Tuo Tea, Pu-erh Tuo Cha, Compressed Tea
Plant Profile
Tuo cha is a compressed tea from Yunnan, shaped like a small bowl or bird’s nest and weighing anywhere from a hundred grams to a quarter of a kilo. It is made from the large-leaf variety of the tea plant, Camellia sinensis var. assamica, steamed and pressed while the leaves are still soft.
The form dates to the caravan trade. Loose tea could not survive months on mule back to Tibet, so it was steamed, packed into cloth bags and pressed into shape, then wrapped in paper and stacked five high. Xiaguan has been pressing tuo cha since 1902, and the shape is still made on the same principle.
Science & Biotechnology
Most tuo cha is sheng, raw tea that ages slowly, though shou or ripe tea is also pressed. Ripe pu-erh depends on wo dui, a pile fermentation developed in 1973 in which leaves are heaped, watered and turned for forty to sixty days at 50 to 65°C, driven by Aspergillus niger, Blastobotrys adeninivorans and several yeasts.
The microbiology changes the chemistry substantially. Catechins fall, theabrownin and gallic acid rise, and the liquor turns from bitter and green to earthy and dark. One consequence is worth knowing: tea plants accumulate fluoride, and long-term daily drinking of strongly brewed brick tea has caused skeletal fluorosis in Tibetan and Mongolian populations. Caffeine remains at three to four per cent.
Uses & Benefits
The cake is broken with a pick, rinsed once with boiling water and then brewed at 95 to 100°C, several short infusions rather than one long one. Two to five grams per session is typical.
Storage matters more than for most tea: 60 to 70 per cent relative humidity, no light, no kitchen smells, and air movement. A tuo kept dry and clean improves for a decade or two; one kept in a plastic bag simply goes flat. Health claims around weight and cholesterol are weaker than the marketing suggests. A tuo broken into chunks keeps better than loose leaf in a humid climate, because only the cut face is exposed.
Growing from Seed
Tea seed is short-lived and should be sown within weeks of harvest, pressed one centimetre into a acid mix at pH 4.5 to 5.5. Germination takes four to six weeks at 20 to 25°C, and the seedlings need shade in their first summer.
Assamica types want 1,200 to 2,000 millimetres of rain and, in Yunnan, 1,500 to 2,000 metres of altitude with mist. Plants are cut back to a plucking table at about a metre and kept there. From seed, the first worthwhile flush comes at four to five years; named clones are raised from cuttings and are more uniform. Seedlings are pricked out at four leaves, since the taproot suffers if it is left in the seed tray.
Our Take
A working tea rather than a luxury one, and the clearest example of how transport shaped a product: the shape exists because mules could not carry loose leaf.
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