Perhaps you all are very familiar with the terms like black tea, green tea, Oolong tea, White tea etc. etc. These are the types of tea now we get in the market. Basically, there are three types of made or processed tea. These are:
(a) Black tea (b) Green Tea and (c) Oolong tea.
Remember, all tea comes from the tender shoots (two to three leaves and a bud) of the Camellia sinensis plant. In future, you will learn in detail about tea manufacture or tea processing. Here, let us have a rough idea about the types of tea we process.
Tea processing has five basic steps; viz., Plucking, Withering (allowing the leaves to wilt and soften), Rolling or cutting the leaves (to rapture the cells to facilitate the polyphenol oxidase, the enzyme to react with the polyphenols for oxidation), Oxidising (Fermentation), and Firing or Drying. The most crucial step what defines the categories of tea, is oxidation, a bio-chemical process. In processing different types of tea, this step is allowed to occur or partially allowed or totally not allowed to occur. Oxidation occurs when the enzymes in the tea leaf interact with oxygen, after the cell walls are ruptured. This is achieved by rolling, cutting, or crushing the leaves. The oxidation process what occurs in tea processing is referred to as "fermentation" by the tea industry. It is, in fact a misnomer.
Now let us see how these types of tea differ in terms of processing.
Black tea is processed by the so-called fermentation process. The fundamental process in making black tea consists of a series of oxidation and condensation of certain substances, mostly the polyphenols. Therefore, it is called oxidised tea. Two kinds of black tea are processed, the Orthodox tea and the CTC tea .Green tea is non oxidised tea. It is plucked, withered and rolled. It is not oxidised. In green tea processing, the fresh leaves are either steamed or pan-fired to deactivate the enzymes before rolling so that oxidation (fermentation) does not occur. It has a more delicate taste and is pale green / golden in colour.
Oolong tea, the semi fermented tea, popular in China, Taiwan and Japan, is withered, partially fermented (between 30% and 70%), and dried. Oolong is a cross between black and green tea in colour and taste. The name is derived from ou-long, the creator of Oolong. A special form of China plant called Che-sima with dark green bluish leaves, are used for making oolong teas which have unique flavour.
There are some other types of tea like White tea, Pu’erh tea etc.
White tea is a very rare tea from China. White Tea is essentially unprocessed tea. The name is derived from the fuzzy white "down" that appears on the unopened or recently opened buds on the tea bush. White tea is simply plucked and allowed to wither dry.White tea is not oxidised or rolled, but simply withered and dried by steaming.
Pu’erh tea is a completely different type of tea. Pu'erh is only produced in the Yunnan province of southern China and is one of the oldest forms of tea. It is also the only tea that is actually fermented and not just oxidized. It first undergoes a process similar to Green tea, but before the leaf is dried, it's aged either as loose-leaf tea or pressed into dense cakes and decorative shapes. Depending on the type of pu'erh being made (either dark "ripe" pu'erh or green "raw" pu'erh), the aging process lasts anywhere from a few months to several years. Very old, well-stored Pu'erhs are considered "living teas", just like wine. They are prized for their earthy, woodsy or musty aroma and rich, smooth taste.
In Lesson, “Tea Processing”, we shall go deeper into the processing of different types of tea.