Preliminary processing of matcha

In recent years, a variety of new and colorful matcha drinks, foods, and daily necessities have become increasingly popular, and have also been loved and sought after by a large number of consumers. The matcha industry has developed rapidly, and the attention to matcha is increasing day by day.

Matcha processing includes two processes: initial processing (grinding) and refined processing, with multiple procedures and high technical requirements. However, the full process of processing matcha is highly mechanized, continuous, and automated, with a low rate of manual labor, making it an effective production method to alleviate the problem of labor difficulties in tea production.

Matcha initial processing, also known as tea grinding processing. The automation level of tea rolling processing is relatively high, generally achieving continuous production without landing throughout the entire process. The processing technology process is as follows: green storage → leaf cutting → withering → cooling → initial drying → stem and leaf separation → re drying (leaves) → tea rolling. The stem part after the first stem and leaf separation still contains a small amount of leaves, which are then fed into another dryer for re drying, followed by secondary stem and leaf separation. The separated leaves are also used for tea rolling after secondary re drying.

1. Store green

Fresh leaves can be processed upon arrival at the factory, and those that are not processed in a timely manner should be stored green. The fresh leaf storage site should be clean, hygienic, cool, odorless, well ventilated, and not exposed to direct sunlight. The storage thickness of fresh leaves should not exceed 90 centimeters. During the storage process, attention should be paid to maintaining the freshness of fresh leaves to prevent them from overheating and turning red. Fresh leaves harvested in hot weather at noon may heat up or dehydrate after being exposed to sunlight. Therefore, an atomizer can be used to cool and preserve the fresh leaves to ensure their quality.

2. Leaf cutting

To ensure the uniformity of the raw materials, fresh leaves need to be cut. The fresh leaves from the green storage tank are uniformly fed into the tea leaf cutting machine through a conveyor belt for horizontal and vertical cutting. The length of the fresh leaves at the discharge outlet is uniform, with a production capacity of 100-500 kilograms per hour.

3. Closing ceremon

Use steam or steam hot air to preserve chlorophyll as much as possible, making the dry tea green in color. Use saturated steam or high-temperature superheated steam for withering, with steam temperature of 90 ℃~100 ℃, steam flow rate of 100~160 kg/hour, green leaf flow rate of 90~120 kg/hour, drum speed of 30~50 rpm, stirring shaft speed of 300~600 rpm, and withering time of 8~10 seconds.

4. Cooling

The withering leaves are blown into the air by a fan and lifted multiple times in a cooling network of 8-10 meters to quickly cool and dehumidify. Cooling time is 5-10 minutes, until the moisture in the tea stem and leaves is redistributed, and the tea leaves are soft when pinched by hand.

5. Initial drying

The commonly used brick tea grinding furnace is the digging well type to create a unique flavor of tea grinding “furnace aroma”, but there are also cases where box type tea grinding furnaces or far-infrared dryers are used for initial drying. There are multiple layers of stainless steel conveyor belts with a width of 1.8-2.0 meters inside the tea rolling furnace. The blades move forward on the multiple layers of conveyor belts by air exchange, passing through four different temperature conveyor belts and taking 20-25 minutes to complete the initial drying.

6. Stem and leaf separation

Using a stem leaf separator with a semi-circular metal mesh structure, the built-in spiral knife peels off the leaves from the stem when rotating. The peeled tea leaves are transported by a conveyor belt to a high-precision air separator to separate the leaves and stems, while removing impurities.

7. Re drying

Use a dryer. Set the temperature of the dryer to 70 ℃~90 ℃ for 15~25 minutes, and control the moisture content of the drying leaves to be below 5%.

8. Grinding tea

After re drying, the initial processed product of matcha is ground tea, which has a bright green color, uniform size, cleanliness, and prominent seaweed aroma.