The processing steps of green tea matcha powder:

(1) Fresh leaf stall
Same as the green tea processing and spreading process. Spread the collected clean fresh leaves thinly on a bamboo board in a cool and ventilated place to allow the leaves to lose some moisture. The spreading thickness is generally 5-10cm. The usual time for spreading tea is 8-10 hours for spring tea and 7-8 hours for autumn tea. Spread fresh leaves until the buds and leaves are soft and the color of the leaves is dark green, with a weight loss of 5% to 20%. During the fresh leaf spreading process, depending on the speed of the withering process, it is necessary to constantly grasp the different thickness and ventilation level of the fresh leaf spreading, and adjust the spreading time at any time

(2) Green protection treatment
The green protection process is carried out during the fresh leaf spreading process. When placed 2 hours before withering, apply a certain concentration ratio of green protectant to the fresh tea leaves for green protection technology treatment, allowing it to take effect and produce a green protection effect. Green protection treatment is necessary
Be careful when flipping, and do not cause mechanical damage to the fresh leaves to prevent them from turning red and affecting the quality of ultrafine green tea powder.

(3) Finished filming
The purpose of withering is the same as that of processing ordinary green tea, aiming to destroy the activity of enzymes in fresh leaves, prevent the enzymatic oxidation of polyphenolic compounds, prevent the leaves from turning red, and ensure the fresh green color and clear soup color of the tea powder. Evaporate a portion of the water inside the leaves, reduce cell turgor pressure, enhance resilience, and make the leaves softer. As the water inside the leaves evaporates, it emits a grassy aroma, gradually revealing the high point aromatic substances, which is conducive to the formation of fragrance.

Fixation technique: High temperature killing is required, but the temperature should not be too high. Otherwise, although enzyme activity is destroyed quickly, the physicochemical changes of other substances in the leaves cannot be completed in time, which is not conducive to the formation of ultrafine tea powder quality. The process of withering ultrafine green tea powder can be carried out using drum withering and steam withering methods.

① Drum withering: Similar to the withering of ordinary green tea. The rotation speed of the cylinder during the finishing process is 28r/min. When the temperature at the center of the simplified outlet reaches 95 ℃ or above, the blade feeding process begins, and it takes 4-6 minutes to complete the finishing process.

② Steam withering: Using high-temperature steam generated by a steam withering machine, enzyme activity in fresh leaves is passivated through rapid steam infiltration. For example, the 800KE-MM3 steam sterilization machine produced in Japan is used for sterilization. The water pressure for steam sterilization is 0.1MPa, the steam volume is 180-210kg/h, the conveying speed is 150-180m/min, the inclination of the cylinder is 4-7 °, and the rotation speed of the cylinder is 34-37r/min. If the moisture content of fresh leaves is high, the steam flow should be controlled to a maximum of 270kg/h, the conveying speed should be 180-200m/min, the inclination of the simplified tube placement should be 0 °~4, and the rotation speed of the simplified tube should be 29-33r/min. During the withering process, attention should be paid to the consistency of steam temperature, and sudden changes in temperature should be avoided. Different methods of withering have varying effects on the main chemical components in the withering leaves. Microwave assisted green tea has the highest polyphenol content, followed by pan fried green tea and steam assisted green tea.

Although microwave withering and steam withering have relatively short durations, fresh leaves still need to undergo dehydration treatment after steam withering, resulting in a significant decrease in tea polyphenol content during the dehydration process; The amino acid content is highest in pan frying and withering, as the pan frying and withering time is longer and the protein hydrolysis is sufficient, the amino acid content increases; Chlorophyll content, steam killing green leaves is higher than microwave killing green leaves, and microwave killing green leaves is higher than pan frying killing green leaves; There is little change in the content of soluble sugars and water extracts. The phenol/ammonia ratio of steam killed ultrafine green tea powder is the smallest, so the taste of steam killed ultrafine green tea powder is fresher and more mellow. The difference in chlorophyll content determines that the color of steam killed ultrafine green tea powder is better than that of microwave killed and pan fried killed.

(4) After steam withering, the water content of the dehulled leaves increases due to the high temperature and rapid steam infiltration. The leaves soften and easily stick together into clumps. Therefore, the dehulled leaves after steam withering should be directly put into the dehulling machine for dehulling, and cooled and dehydrated with strong wind. Leaf beating should be carried out at a constant speed to ensure that the water loss of the killed green leaves is moderate, in order to ensure the quality of the ultrafine green tea powder product. If the roller killing method is used to process ultrafine green tea powder, this process is not required.

(5) Rubbing and twisting
Due to the final crushing of ultrafine green tea powder, there is no need to consider how to facilitate shaping during the rolling process. The rolling time is shorter than that of ordinary green tea, and its main purpose is to destroy leaf cells and enhance the concentration of ultrafine green tea powder flavor. The rolling technology must be determined based on the performance of the rolling machine, as well as the age, tenderness, uniformity, and withering quality of the leaves. Special attention should be paid to mastering the technical aspects such as leaf feeding amount, time, pressure, and rolling degree in order to improve the rolling quality and ensure the product quality of ultrafine green tea powder. Using the 6CR55 rolling machine for rolling, a suitable leaf feeding amount of 30kg per bucket or unit is recommended. Pressure and time, tender leaves take about 15 minutes, with light pressure for 4 minutes, heavy pressure for 7 minutes, and light pressure for 4 minutes before being removed from the machine; Old leaves take about 20 minutes, including 5 minutes of light pressing, 10 minutes of heavy pressing, and another 5 minutes of light pressing before being removed from the machine; The appropriate degree of kneading is when the leaves are slightly curled, the tea juice seeps out, and the hand feels sticky without clumping.

(6) Splitting and screening
Splitting and screening is a very important process that needs to be carried out after rolling and twisting. Due to the leakage of tea juice from rolled leaves, it is highly prone to sticking into clumps. If not separated and screened, the dried product will have uneven dryness and a non green color. After disassembling and screening, the leaf size is basically the same. Then, the screened leaves are kneaded again to achieve a consistent degree of kneading, which is beneficial for improving the color and quality of ultrafine green tea powder products.

(7) Dehydration and drying
It is divided into two stages: initial drying and foot drying, during which a cooling and moisture recovery process is required.

① Initial drying: The purpose of initial drying is the same as that of initial drying of green tea. The initial drying process is completed under certain temperature and humidity conditions. At this time, due to the high moisture content of the leaves, chlorophyll is greatly destroyed under humid and hot conditions, and the release of low boiling aromatic substances is hindered, which is not conducive to the transformation of the quality of ultrafine green tea powder. Research has found that microwave drying is a better method for initial drying of ultrafine green tea powder. This method has a shorter dehydration time and is beneficial for improving the chlorophyll content retention rate and sensory quality of ultrafine green tea powder.

② Foot drying: The purpose of foot drying is to continue evaporating water, reducing the moisture content during leaf making to below 5%, while developing tea aroma. It is better to use microwave drying method for dry feet. Microwave magnetron heating frequency: 950MHz, microwave power: 5.1kW Transmission power: 83% power, conveyor belt width: 320mm, microwave time: 1.8-2.0min. It is advisable for the moisture content of dry tea to be less than 5%.

(8) Ultrafine pulverization

The quality of ultrafine particles of ultrafine green tea powder is mainly determined by the following three factors:

① Moisture content of semi-finished products: The moisture content of semi-finished products processed with ultrafine green tea powder must be controlled below 5%. The higher the moisture content of semi-finished products, the better the fiber toughness, and the harder it is for fibers and leaf flesh to break under external forces.

② External force application method: The fibers and leaf flesh of semi-finished dried tea plants need to be broken and crushed by external force to form ultrafine particles of ultrafine green tea powder. The diameter of the particles varies depending on the external force applied (crushing method). Both wheel grinding and ball milling methods are used for crushing under the action of rotational force, which is not conducive to the fracture and crushing of tea stems and stems; The straight rod type is based on the principle of hammering, which has the functions of shearing, friction, and tearing. It crushes dry tea plant fibers and leaf flesh thoroughly and has a good effect.

③ The temperature of crushed material tea: green color and fine particles are the main factors affecting the quality of ultrafine green tea powder. In the process of ultrafine grinding, as the grinding time prolongs, the crushed material tea undergoes intense friction, shearing, and tearing between the materials, which generates heat and causes the temperature of the crushed material tea to continuously rise. Chlorophyll is destroyed under the action of heat, and the color of ultrafine green tea powder turns yellow. Therefore, during the process of crushing ultrafine green tea powder, the temperature of the crushed material tea must be strictly controlled, and the crushing equipment must be equipped with a cooling device.
The current widely used method for crushing ultrafine tea powder in China is air flow crushing. However, the ultrafine tea powder produced by air flow pulverization has a lower degree of pulverization, and due to the relatively high-speed air flow during the pulverization operation, volatile components are easily taken away, resulting in low product aroma.
Research has shown that among the main methods currently used, such as wheel milling, air flow crushing, frozen crushing, and straight rod hammering, the straight rod hammering crushing method is the most suitable for crushing tea leaves. The pulverization equipment designed and manufactured based on the principle of straight rod hammering has different ultrafine pulverization times due to the different tenderness of the raw materials. The older the raw materials, the longer the pulverization time. The ultrafine crushing equipment using the principle of straight rod hammer is used to crush tea leaves, with a crushing time of 30 minutes and a leaf feeding amount of 15 kg.

(8) Finished product packaging
Ultra fine green tea powder products have small particles and are easily able to absorb moisture from the air at room temperature, causing the product to clump and spoil in a short period of time. Processed ultrafine tea powder should be promptly packaged and stored in a cold storage with a relative humidity below 50% and a temperature range of 0-5 ℃ to ensure product quality.