The processing principle and technology of black tea matcha powder

Black tea matcha powder is processed from fresh tea leaves through withering, rolling, fermentation, dehydration and drying, and ultrafine grinding. Its quality features include delicate and uniform particles, brown red color, mellow and sweet taste, rich aroma, and deep red soup color.

Compared with ordinary black tea, black tea powder has a very fine particle size (usually around 300 mesh), and its color, taste, and aroma are basically the same as ordinary black tea. Fresh tea leaves in spring, summer, and autumn can all be processed into ultrafine black tea powder, and summer and autumn fresh leaves are the best raw materials.

Processing steps for black tea powder: Fresh leaves → Withering (natural withering, withering in a withering trough, or withering under sunlight) → Rolling → Breaking and screening, fermentation → Dehydration and drying → Ultra fine grinding → Finished product packaging.

(1) Withering

The purpose of withering is the same as processing regular black tea.

There are three methods of withering: withering trough withering, natural withering, and sun withering. The specific methods are the same as black tea processing. Wilting degree: The leaf surface loses its luster, the leaf color is dark green, the leaf quality is soft, it can be kneaded into a ball by hand, the stem is constantly folded, there are no withered buds, burnt edges, or red leaves, and the green grass scent has partially disappeared, with a slight fragrance. If moisture content is used to control, the moisture content should be controlled between 58% and 64%. Generally, it is 58% to 61% in spring, 61% to 64% in summer and autumn, and the weight loss rate of fresh leaves should be between 30% and 40%.

(2) Rolling

Rolling black tea powder does not require consideration of how it is shaped. Its purpose is to destroy leaf cells, allow polyphenol oxidase in the leaves to come into contact with polyphenolic compounds, and promote fermentation through the action of oxygen in the air.

Rolling technology: The room temperature for rolling black tea powder is controlled at 20-24 ℃, with a relative humidity of 85% -90%. It can be carried out using a 6CR55 rolling machine. Technical parameters: The leaf feeding capacity for a single barrel or machine is about 35kg; Rubbing and twisting should be carried out in stages for about 70 minutes, with materials of grade one or above being kneaded three times, each time for 20, 30, and 20 minutes respectively; Rub the raw materials below level 2 twice, each time for 35 minutes, and do not apply pressure for the first 35 minutes.

Rolling degree: The leaves curl and become sticky by hand, allowing the tea juice to be fully kneaded without loss. The leaves are partially red and emit a strong aroma.

(3) Splitting and screening

After each rolling, the tea should be separated and sieved, and the sorted tea should be fermented separately.

(4) Fermentation

The purpose of fermentation is to enhance the activation level of enzymes, promote the oxidation of polyphenolic compounds, produce rich aroma in leaves, and form the color and taste of ultrafine black tea powder. Fermentation technology: indoor temperature of 25-28 ℃, relative humidity of over 95%. Spread tender leaves with a thickness of 6-8cm and mid-range leaves with a thickness of 9-10cm, and ferment for 2.5-3.0h; The old leaves are 10-12 cm and the fermentation time is 3.0-3.5 hours. Fermentation degree: The leaves are red in color and emit a strong apple aroma.

(5) Dehydration and drying

① Dehydration and drying purpose: To use high temperature to destroy enzyme activity, stop fermentation, and fix the quality formed. The evaporation of water continues to release the scent of green grass, further developing the tea aroma.

② Dehydration and drying technology: After fermentation, the leaves have formed a relatively stable black tea color. Therefore, color protection issues can be ignored when processing ultrafine black tea powder through dehydration and drying, and the equipment can be used with a regular dryer. Drying is divided into initial drying and sufficient drying, with a cooling period of 1-2 hours in between. The principle of high temperature and speed is mainly mastered during initial drying, with temperature controlled at 100-110 ℃ for 15-17 minutes. After initial drying, the leaf moisture content is 18% -25%. Immediately cool down after initial drying, and after 1-2 hours of water redistribution, perform foot drying. Foot drying should follow the principles of low temperature and slow drying. The temperature should be controlled at 90-100 ℃ for 15-18 minutes. After foot drying, the moisture content of the leaves should be below 5%. At this time, the leaves should be crushed into powder by hand, with a dark and smooth color and a strong aroma.

(6) Ultrafine pulverization

This process determines the particle size of black tea powder products and plays a decisive role in product quality. Like green tea powder, black tea powder has different ultrafine grinding times due to the different tenderness of the raw materials. The older the raw materials, the longer the grinding time. Under normal circumstances, the crushing equipment using the straight rod hammer principle is used for crushing, with a single blade feeding of 15kg and a crushing time of 30 minutes.

(7) Finished product packaging

Like green tea powder, black 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 black 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.