The tea plant is a member of the Camellia family (Camellia sinensis). The wild plant can grow to 30 metres high. In the past, trained monkeys picked the leaves and threw them down to be collected, but nowadays the plant is grown to a height of just one metre in commercial tea plantations to make harvestation easier and more efficient.
The bushes are hand plucked every 7-14 days, varying according to climate, altitude and soil conditions which affect the rate of regrowth. The system of plucking varies between each plantation estate, but on average the bud and two or three mature leaves are removed.
The tea leaves are then taken to the factory where they are laid on trays or racks and left to wither in air at 25-30 degrees centigrade. This process takes between 10-16 hours depending on how wet the leaf is. This process is vital since rolling wet leaves results in a loss of juice which contains essential matter. The withered leaf is then taken to the rolling machine to break up the leaf and release the remaining juices.
The next stage involves breaking up the withered leaves in order to bring the natural juices containing enzymes into contact with the air, which enables oxidisation of the enzymes to take place. There are two main methods: cutting using an 'Orthodox' machine which rolls the leaf, producing large leaf particles, and cutting using an 'Unorthodox' or CTC machine (cutting, tearing and curling), which produces much smaller particles. The leaf particles are then laid out for 3-4 hours to ferment until they are a golden russet colour. The fermented leaves are taken to the firing room to evaporate all the moisture. During this process the leaf turns dark brown or black. Afterwards the leaves are sifted (or graded) through a series of wire mesh sifts before being weighed and packaged.
Green tea is mainly drunk in China, Japan and some parts of South America. It is produced by a slightly different process to black tea; the withered leaf is steamed and rolled before the processes of drying and firing in order to avoid breaking the leaf veins and therefore prevent the fermentation of the leaf green tea tastes slightly bitter since the enzymes are still contained in the leaf.
In contrast, Oolong tea is semi-green (or semi-fermented
tea). It is produced in the same way as black tea except the fermentation
process is reduced by half to 1-2 hours. Other factors affecting flavour
are the blending of teas from different regions or the addition of flowers,
fruit, oils, herbs or spices from other plants.