As mentioned in a previous post, there are only two types of varieties in the camellia sinensis plant which are commonly used for tea. Therein lies the question “How in the name of all that is holy can there be so many kinds of tea?” As a very general sort of figure, there are seven categories. Whites, greens, yellows, oolongs, blacks, pu-erhs, and tisanes, but that is generalized, to the point of which, according to my tea instructor, you could ask a farmer how many different kinds of tea they grew, and they could tell you in response “upwards of eight hundred.”
There are six basic steps to make various teas. Please note that these steps do not apply to tisanes, which warrant another post entirely.
- Plucking: In this step, the leaves are plucked from the bush. Sounds simple enough, right? Apparently it is a lot harder than one might have thought (or the guy in the video is awful at manual labour) The standard pluck is “two leaves and a bud” If it is a prestigious tea garden, they are expected to consistently be a quality comparable to the one in the picture. Some tea plucking has been mechanized, but snobby tea connoisseurs almost always associate that with low quality tea, with the exception of Japanese teas.
- Withering: This step in itself is essentially just laying the plucked leaves out on a tray, then leaving them to dry for a while. Excess water in the leaves evaporate, to the point in which a tea leaf can lose as much as a quarter of its weight.
- Sorting: The leaves are sieved through a series of smaller and smaller sieves to sort the leaves into size. (image courtesy from here) Tea leaves are then graded. Usually the larger leaves get higher final grades.
- Oxidation: You know when you bite into an apple, leave it for a while, and then it turns brown? That is what oxidation is. In a more specific sense, the sorted leaves are left out in a controlled environment of humidity and temperature, for a specified amount of time. It is more-or-less a controlled version of the withering stage. This stage is the one that differentiates teas from one another. It greatly depends on the tea being produced, but black teas, for example, are at 100% oxidation, while oolong teas can be anywhere at 1%-99% oxidization, depending on the desired outcome. In short, any tea grown from any region can be any type of tea. Farmers from South Africa could produce green teas if they wanted to. Generally speaking, the less oxidized, the lighter the tea will taste. Green teas and white teas do not go through this step, but seeing as it is impossible to avoid the leaves coming in contact with oxygen, one could argue that all teas are at least semi-oxidized.
- Firing: Everybody seems to call this killing the green, but I think that is a confusing way to put it. This step is done to stop the oxidation process at the desired level. Traditionally it is done in a wok, but nowadays some people put it on a giant conveyor belt running through an oven. Japanese firing is done by steam instead of dry heat, which contributes to their unique marine tastes.
- Shaping: The leaves are shaped into its final form. Some are rolled into tiny balls or pearls, and some are curled. Sometimes they aren’t shaped at all and they move onto their next step. There is a process called CTC (cutting, tearing, and curling), in which teas are broken down into very fine particles. They are usually used for tea bags, and it has been said that CTC teas account for more than 90% of tea.
- Drying: Here the leaves receive a final drying. It’s important to take care in not cooking the tea leaves, and instead just drying them out. It is a fine line
These steps are just a guideline for teas, but specific teas, like oolongs, whites, post-fermented black teas (pu-erhs) require modification to these steps, and sometimes even more steps.