The processing procedure of tea black tea and oolong tea go through different processes.

The processing of tea

As mentioned earlier, all real teas are made from the same leaves-differences in color, aroma and taste come from the way they are treated after harvest. Tea can be withered, dried, oxidized, fired and shaped according to the type of tea you want. For example, the leaves of green and white tea are not oxidized at all-the leaves are dried in the sun, fried or steamed in a pan, and then made into particles or twigs. Green tea can also be ground into matcha green tea powder.

On the other hand, strong teas such as oolong tea and black tea are produced through oxidation. At this stage, the leaves wither and curl to promote the reaction of enzymes in the leaves with oxygen. Compared with exquisite real tea such as green tea and white tea, this process makes the tea darker in color and more full-bodied in taste. The oxidation process includes two methods, the most common of which are the traditional method and the CTC method.

An orthodox method

For traditional methods, tea is treated in four steps, including withering, rolling, oxidation and drying. In the production process, each step helps to produce the flavor associated with dark real tea.

Withering

Tea is transported from the field to the tea factory within a few hours after picking and sorting. Leaves destined to turn black or oolong tea will wither to reduce moisture content so that the leaves can be rolled up without peeling off. The water content of harvested tea is usually very high, about 75%, but after rolling and oxidation, the water content will be reduced to about 45%. Place the leaves on a flat or bamboo tray to remove moisture. During the drying process, leaves stay in cool air for 8 to 18 hours.

Knead and roll

Once the leaves wither, they roll up to promote oxidation. In traditional production methods, leaves are rolled by hand, although in modern times, many manufacturers use coiling machines to speed up the process. When withered leaves are rolled up, the internal cellular structure is destroyed, releasing essential oils that react with oxygen to form a fragrance.

Oxidation

After the tea is rolled up, it goes through an oxidation process, also known as fermentation, which determines the strength and taste of the tea. The interaction between enzymes and oxygen breaks down chlorophyll and releases tannins, which darkens the leaves. The oxidation process is controlled by tea producers, who maintain a warm, humid environment.

The temperature is kept between 80 and 85 degrees Fahrenheit, and the length of the oxidation process leads to different types of real tea. As mentioned earlier, non-oxidizing teas, such as green and white teas, maintain green and botanical flavors. Semi-oxidized tea is a kind of tea that has only been oxidized for a short time, such as oolong tea, which is generally light brown or yellow and has a light taste. Fully oxidized tea, such as black tea, is reddish brown in color and strong in taste.

Drying

In order to prevent the oxidation process, the tea should be dried. According to tradition and the preferences of tea producers, tea can be dried in a pan, sun-dried or baked. Leaves are subjected to temperatures of more than 100 degrees Fahrenheit to stop the oxidation process and reduce water content to only 2-3%.

CTC method

The CTC production process is called extrusion-tear curling, and the result is the crushing of tea and granular particles. CTC tea goes through the same process of wilting, oxidation and drying as ordinary tea. The main difference between the traditional method and the CTC method occurs in the scrolling phase. In the CTC production process, the tea is rolled into a machine with hundreds or small sharp teeth. These spikes break down the tea into smaller fragments, which are usually used in tea bags.