According to data from the Ministry of Agriculture and Rural Affairs, the total output of rough tea in China in 2025 for 3.368 million tons, of which 1.867 million tons are green tea, accounting for 55.4% of the total output. Green tea occupies an absolute dominant position among the six major tea categories in China. Today,Shenzghou Houtu Tea CO.,LtD will learn about the processing technology of green tea with everyone.
1. Picking Fresh leaf
The raw materials determine 70% of the final quality of dried tea products, so harvesting is a crucial step. However, fresh leaf picking is often a seriously overlooked step in the processing technology. Picking standards are a very complex thing, mainly influenced by time. Generally, the picking standards for spring tea are relatively high, especially for Pre-Qingming tea. This wave mainly focuses on famous and high-quality tea because the final tea product has a high price and a large premium space, so tea farmers are willing to spend time picking it. There are those who pick single buds, those who pick one bud and one leaf, and those who pick one bud and two leaves. Before the Pre-Qingming tea, tea was basically harvested with one bud and two leaves, and most of them were manually picked.
After Qingming Festival, the average temperature during the day is generally above 20 ℃, and tea trees grow quickly. In addition, the price of tea cannot be sold after the festival, so the later picking is usually one bud, two leaves, and three leaves, and often machine picked.
2. Spreading
After picking fresh leaves, they are spread out, also known as spreading green leaves. The main purpose of spreading green tea is threefold: firstly, to stimulate enzyme activity and release effective ingredients. Please note that the enzymes referred to here are not polyphenol oxidase, but other hydrolytic enzymes. The green soup and leaves that green tea emphasizes are most afraid of being oxidized by polyphenol oxidase to turn tea polyphenols red. The tea polyphenols in fresh leaves are located in vacuoles, while polyphenol oxidase is mainly found in chloroplasts and mitochondria, which are normally inaccessible to the two. But if the picking action is too large, or if the fresh leaves are damaged during storage and transportation, it is extremely easy to cause vacuoles, mitochondria, or chloroplasts to rupture, and tea polyphenols to oxidize and turn red.So green tea fresh leaves should be treated lightly before fixation to minimize damage to the leaves.
Another function of spreading is to dissipate the green odor. After picking fresh tea leaves, there is a strong grassy aroma, mainly due to the low boiling point of grassy alcohol or grassy aldehyde. Spreading can cause most of these low boiling point substances to dissipate, but it also takes time. If time is not enough and the loss is not thorough, the finished tea leaves will be heavy.
Another function of spreading is to dissipate some water, reduce the fragmentation rate of subsequent Fixation.
When placed in place, the leaves are soft and can form clusters when tightly grasped. The color of the leaves turns dark green, and the scent of green grass decreases, revealing a fragrant aroma. Using a specific data, the moisture content of the green leaves should be controlled between 65% and 70%.
3.Fixation
After the Spread, it needs to be fixation. The main purpose of withering is to kill the activity of polyphenol oxidase and peroxidase, and avoid the oxidation of tea polyphenols into theaflavins, thearubigins, etc. by polyphenol oxidase and peroxidase. This is also the core step for green tea to maintain its green soup and leaves, also known as the three greens.
The process of withering can further release green energy and develop tea aroma, which is also caused by the mutual transformation of related substances in the tea leaves through the action of enzymes or heat during the withering process. Another finishing can evaporate some moisture, which is beneficial for subsequent shaping.
4 Rolling
After Fixation, the next step is rolling and twisting, which is an important process for shaping the appearance of tea leaves by applying external forces to shape them. At the same time, it moderately damages the leaf cell tissue, and the tea juice is squeezed out and adhered to the surface, making the tea color oily and easy to brew.
The principle of kneading is to hot knead the old leaves, gently knead the tender shoots (cold knead), and apply pressure lightly. The crushing rate of rolled leaf cells is generally 45% to 55%, and the hand feels moist and sticky.
During the rolling process, the frequency, time, and pressure of rolling are mainly controlled, as well as the amount of tea leaves added. Some parameters can be set on the machine, while others need to be adjusted based on actual situations and experience.
Rolling is usually done slowly at first and then quickly, but the speed should also be controlled within an appropriate range. Another type of kneading is usually done clockwise. Sometimes, if you find that the tea leaves become looser as you knead them, you need to check if the direction is reversed.
5 Dry
The rolled tea leaves are now dry. The purpose of drying is to organize the strands, shape the appearance, develop the tea aroma, enhance the taste, evaporate water, achieve sufficient dryness, and facilitate storage. According to different drying methods, it can be divided into drying, stir frying, and sun drying.
This is also the origin of what we often refer to as roasting, frying, and sun drying. Another method is steaming green, which is not a drying method, but a withering method.
The drying process is often divided into several stages and cannot be fully dried in one step. This depends on the type of tea, and the final state is that the moisture content of the tea leaves should be less than 7%. The value of 7% is specified in the national standard (9% for sun drying), and in actual operation, it is generally dried to a moisture content of 4% to 6%. Because tea also absorbs moisture from the air during storage, the moisture content after drying must be lower than 7%. The lower the moisture content, the more stable the quality of tea, as biochemical reactions require water. However, if the moisture content is too low, such as below 3%, the tea leaves are very easy to break or squeeze into powder, which is not conducive to the transportation of tea leaves.
6.
6 Refined
The green tea that has been dried is called green tea, which can be brewed and consumed. But in reality, there is still a refining process to follow. Refining is mainly carried out through circular screening machines and shaking screening machines to distinguish between size and thickness. Then Winnowing further distinguishes the specifications, performs electrostatic or manual picking operations to remove impurities, and finally improves the quality through a color sorter. As a commercial tea, some are also blended and reheated for drying.
