Tea types
Six categories, all from the same plant. What separates them is not where they grow or how they taste but what was done to the leaf in the hours after it was picked.
Tea taken deliberately through full enzymatic oxidation, giving the dark leaf, amber-to-red liquor and malty or brisk character most Western drinkers think of as simply 'tea'.
What defines it: Full enzymatic oxidation of the rolled or cut leaf, halted only by firing once oxidation is complete.
Tea whose oxidation is halted early by heat, keeping the leaf green and the cup fresh, vegetal or marine in character.
What defines it: Kill-green (fixation) applied before meaningful oxidation can develop.
Partially oxidised teas, bruised deliberately and often roasted — the widest-ranging category in tea.
What defines it: Deliberate bruising to initiate edge oxidation, halted partway, frequently followed by roasting.
Teas changed after processing by microbial activity — either deliberate wet-piling or long, slow ageing.
What defines it: Post-fermentation: microbial wet-piling (shou) or extended natural ageing (sheng).
The least handled category: withered and dried, with no fixation and no deliberate rolling.
What defines it: Withering and drying only, with no fixation and no deliberate rolling.
The rarest of the six categories: a green tea given an extra smothering step that removes its grassy edge and leaves a rounder, mellower cup.
What defines it: Sealed yellowing (men huang) applied to the fixed leaf, between fixation and final drying.
Why there is no seventh category
Herbal infusions are not tea. Chamomile, rooibos and peppermint are not Camellia sinensis and share none of its chemistry, so they are modelled separately and held out of publication until their evidence has been through human review. Grouping them with the six above would imply an equivalence that does not exist.
Purple tea, GABA tea and milk oolong are likewise not categories. The first is a cultivar, the second a processing atmosphere, the third an aroma — all three sit inside the six.