the processing process of Tencha

The processing of matcha is not simply grinding green tea into powder, it is mainly divided into two stages: “initial processing (Tencha)” and “refinement”. Fresh leaves are first processed into a semi-finished product called “Tencha” through initial processing techniques such as steam withering and stem leaf separation. Today, we will take you into the production workshop to learn in detail about the process flow of initial processing (Tencha) of matcha.

1. Storage of fresh leaves

Fresh leaves must be shaded and processed at the factory after harvesting. Those that cannot be processed in a timely manner need to be stored green. The fresh leaf storage site should be clean, hygienic, cool, odorless, well ventilated, and not exposed to direct sunlight. The thickness of fresh leaves should not exceed 90cm and the storage time should not exceed 10 hours. 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. Tea leaves 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 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 ceremony

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 an 8-10 meter cooling network to quickly cool and dehumidify. Cooling time is 5-10 minutes. Cool until the water in the tea stem and leaves is redistributed, and the tea leaves become 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.Separation of stems and leaves (key to removing bitterness)

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. Tencha

After re drying, the initial processed product of matcha is tencha, which has a bright green color, uniform size, cleanliness, and obvious seaweed fragrance.