JP2019037216A5 - - Google Patents

Description

(A) Withering step The wilting step in the present invention is a step of wilting the harvested green tea leaves in a ventilation environment until the water content is reduced to less than 72% and 50% or more , preferably 60 to 50%. By this step, the water content of the fresh tea leaves can be reduced, the time required for the subsequent first drying step can be shortened, and the production cost can be reduced. The fresh tea leaves used in this step are as described above, but in order to improve the drying efficiency, the fresh tea leaves may be appropriately cut before wilting. In this step, it is preferable to use a fresh leaf management machine for storing fresh tea leaves, and the temperature environment around the fresh tea leaves during wilting is preferably 10 to 40 ° C, which is room temperature, and more preferably 20 to 30 ° C. Ventilation is performed to prevent the temperature of the fresh tea leaves from rising due to respiration, and the ventilation cycle may be constant ventilation or intermittent ventilation with a certain rest period. In addition, ventilation can be done from any direction. When the ambient temperature is low, warm air of 20 to 40 ° C. may be blown.

(C) First Drying Step The first drying step in the present invention is to smoothly extrude with a screw, crush with friction, and shear with a cutter in the subsequent squeezing and crushing step, and tea leaves in the subsequent crushing step. This is a step of exposing the tea leaves to hot air at 50 to 150 ° C. to reduce the water content of the tea leaves in order to make it easier to unravel the lumps. If the water content of the tea leaves is too high in the subsequent squeezing and crushing step, a large amount of water is squeezed out from the tea leaves, which tends to form lumps after the squeezing and crushing step, making it difficult to crush. On the contrary, if the water content of the tea leaves is too low, the frictional force between the machine and the tea leaves becomes stronger in the squeezing and crushing process, the tea leaves cannot be extruded, and the inside of the machine may be clogged. Therefore, in this step, the water content is reduced to less than 71%, 30% or more , preferably 60 to 40%, and more preferably 50 to 40%. In this step, for example, a rotary cylinder made of wire mesh that can supply hot air at 50 to 150 ° C. like a steamed leaf processing machine manufactured by Kawasaki Kiko Co., Ltd., or a rotary cylinder made of wire mesh that can supply hot air at 50 to 150 ° C. and rotates in the cylinder. A fixed cylinder with a leaf-steaming hand can be used. Further, the hot air generator in this process sends out the outside air heated by the fireplace with a blower fan and supplies it as hot air, as used in a ventilation dryer, regardless of whether it is for tea production, and further, the roasting steaming is performed. The exhaust heat from the roasting and steaming process can be reused from the fireplace of the rotary cylindrical kettle in the process through the exhaust heat duct. Further, when the exhaust heat of the roasting and steaming step is reused, outside air can be appropriately supplied to stabilize the hot air temperature.

Claims (9)

(B) A roasting and steaming step for inactivating the oxidizing enzymes of fresh tea leaves, and (C) The tea leaves that have undergone the above (B) roasting and steaming step are exposed to hot air at 50 to 150 ° C., and the water content is less than 71% and 30%. a first drying step to reduce to above, and (D) while applying a pressure to equalize the moisture distribution in the tea leaves through said (C) first drying step, pressing pulverizing step of shearing and crushing the tea leaves , (E) A crushing step of crushing a mass of tea leaves that have undergone the (D) squeezing and crushing step, and (F) a second step for reducing the water content of the tea leaves that have undergone the (E) crushing step to 5% or less. A drying process and a method for producing green tea, including. The method for producing green tea according to claim 1, wherein (A) a wilting step at room temperature for reducing the water content of fresh tea leaves to less than 72% and 50% or more is performed before the (B) roasting and steaming step. .. (B) the roasted steaming step, while roasted the tea leaves in a cylindrical kettle heated to 300 to 400 ° C., by utilizing the latent heat of water vapor vaporized from the tea leaves, inactivated oxidase of the tea leaves The method for producing green tea according to claim 1 or 2, which is the step of making green tea . Wherein (C) the first drying step, while exposing the inside wire mesh cylinder (B) is roasted tea leaves through a steaming process hot air 50 to 150 ° C., the rotation of the cylinder, or Sarai stirring of the tea leaves by hand was carried out, the method of producing green leaf tea according to any one of claims 1 to 3 is a step of reducing the moisture content of the tea leaves. The method for producing green tea according to any one of claims 1 to 4, wherein the (C) first drying step is a step of reusing the exhaust heat of the (B) roasting and steaming step. The method for producing green tea according to any one of claims 1 to 5, wherein the squeezing and crushing step (D) is a step of using a crusher that performs shearing with a cutter or crushing by friction while applying pressure to the tea leaves. Any of claims 1 to 6, wherein the crushing step (E) is a step of using a crusher which is composed of two sets of rolls in which blades are mounted at equal intervals and rotates so that the blades of the rolls mesh with each other. The method for producing green tea described in Crab . The method for producing green tea according to any one of claims 1 to 6, wherein the crushing step (E) is a step of repeating crushing a plurality of times and performing drying and sieving after each crushing. Manufactured by the manufacturing method of green tea according to any one of claims 1 to 8 green tea, wherein Rukoto.