Tea in its true sense is anything that is made from the Camelia sinensis plant and its sub-varieties. Anything else should be referred to as an infusion or tisane. Colloquially we refer to infusions such peppermint as herbal teas, but the distinction should be made mainly because the natural caffeine content in the tea leaves.
Tea all comes from the same species of plant and the differences in the finished product are governed purely by cultivar, terroir, harvest date and processing method. There are two main ways of cultivating tea: by taking cuttings (knows as clones or clonal tea) or by planting from seed.
Camelia sinesis has several varieties with the two main being var. sinensis and var. assamica. Within these varieties are thousands of cultivars, some of which have been specially developed by particular tea estates for their specific terroir and processing method. For example the AV2 clonal variety is very popular in the Darjeeling region of India.
There are six main types of tea made from Camelia sinensis.
White tea is the least processed form of tea, made only from buds and select leaves of the tea plant. White tea leaves are only able to be plucked at the start of the growing season at the end of winter dormancy. The new growth leaf buds have a white down on them giving white tea its name. Processing consists of only drying and withering the leaves.
Green tea is a processed form of tea, with the leaves withered, then either steamed or pan fried before rolling or shaping. The oxidisation process is halted early on to keep the leaves green and preserve the light, fresh flavours. China has hundreds of cultivars of the tea plant Camellia sinensis, allowing for vast regional variation in flavour and aroma.
Japan produces mainly green teas, known as sencha, which are mainly steamed rather than pan fried.
Yellow tea is the least common type of tea. It is very similar to green tea but the leaves are wrapped in paper and steamed in an extra processing method making the eaves have a slight yellow colour. The steaming slows the oxidation process making the tea more mellow.
Oolong – or wulong – contains many stages in its preparation and comprises a large variety of teas. Infusions range from light green to dark red, depending on how far the tea has been allowed to oxidise and ferment. A general simplification would be to say that oolongs sit somewhere in between green and black teas, though this does not do justice to the array of possible flavours.
Black tea (especially Indian black tea) is the variety most familiar to Western drinkers thanks to its ability to take milk and sugar. Heavily oxidised, it produces a deep red liquor. The range of flavours goes far beyond the well-known breakfast blend, from fruity and delicate, via syrupy and sweet, to rich, smoky, and complex.
Pu Erh comes from Yunnan province and is famous for its fermentation process, like wine its flavour develops with age. Initial processing of the leaves is minimal: leaves are preferably dried in the sun, before being dry roasted in a pan to prevent further oxidation. You will find some Pu Erh teas compressed into cakes or bricks, whilst others remain loose.