JPH0443612B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a method for producing tea, particularly a method for producing coarse tea such as sencha or tencha.

(Prior art) Conventionally, in the mechanical production of rough sencha tea, for example, as described in the "New Tea Industry Zensho" published by the Shizuoka Prefecture Tea Industry Chamber, there are a steaming process, a rough rolling process, and a rolling process. A method was adopted in which the process, medium rolling process, fine rolling process, and drying process were sequentially performed in the order listed. In the steaming process, tea leaves are steamed using latent heat of steam. The rough rolling process involves rolling the tea leaves while exposing them to heated air to soften the tea leaves and evaporate their water content. The rolling process is a process in which the tea leaves are mixed together while being rolled under pressure, thereby compensating for the lack of rolling in rough rolling and smoothing out the moisture in each part of the tea leaves. In the medium rolling process, the rolled leaves are exposed to hot air to evenly remove moisture and create a twisted shape, making it easier to shape the tea leaves. The rolling process involves tightening and drying the tea leaves to form the straight shape unique to Sencha. The drying process is
The heated air is used to remove water from half-dried tea leaves after thorough rolling, and the heat at that time enhances the flavor of the tea.

(Problems to be Solved by the Invention) However, in the conventional method described above, the tea leaves are dried after the steaming process by exposing them to air, which causes the tea leaves to easily oxidize and cause the leaf color to lose its bluish tinge. It was hot.

The present invention aims to solve these problems, and aims to prevent tea leaves from oxidation and maintain a clear blue tint of the leaf color.

[Structure of the invention]

(Means for Solving the Problems) In the tea manufacturing method of the present invention, tea leaves are steamed in a steaming step, and then the tea leaves are vacuum-dried.

(Function) The tea manufacturing method of the present invention prevents oxidation of tea leaves by drying the tea leaves after the steaming step in a vacuum state with almost no oxygen.

(Example) Hereinafter, an example of the tea manufacturing method of the present invention will be described with reference to the drawings.

In this example, the production of rough sencha tea by a machine will be explained.

The entire manufacturing process consists of a steaming process, a vacuum drying process, a rough rolling process, a rolling process, a medium rolling process, a fine rolling process, and a final drying process, and these processes are performed sequentially in the order listed. That is, in all conventional manufacturing processes, a vacuum drying process is added between the steaming process and the rough rolling process.

In this vacuum drying step, for example, a vacuum dryer 1 having a structure as shown in the drawings is used. This vacuum dryer 1 has a heater 3 built into a vacuum chamber 2 having an inlet and an outlet that can be opened and closed, and the vacuum chamber 2 is communicated with the atmosphere via a vacuum pump 4.

Then, the tea leaves steamed by the steamer in the steaming process are carried into the vacuum chamber 2 by, for example, the conveyor table 5. Next, as shown by the thin arrow, the air in the vacuum chamber 2 is removed by the vacuum pump 4, and the tea leaves are vacuum-dried by appropriate heating by the heater 3. Furthermore, the vacuum-dried tea leaves are carried out from the vacuum chamber 2 into which air is returned, and sent to a rough rolling machine for the next process.

Of course, in the vacuum drying step, the tea leaves are not completely dried, but rather a certain amount of moisture remains in the tea leaves, which is necessary for the subsequent rough rolling step.

Furthermore, since the vacuum drying step is added, the amount of dried tea leaves in the subsequent rough rolling step etc. is appropriately reduced.

According to the above method, the tea leaves after the steaming step are dried in a vacuum state with almost no oxygen, so oxidation of the tea leaves can be prevented. Therefore, the green color of the tea leaves can be maintained clearly, and the marketability of Sencha can be improved.

In the above embodiments, a vacuum drying step was inserted between the steaming step and the rough rolling step, but the vacuum drying step may be inserted immediately after the rough rolling step or immediately after the rolling step. Further, the vacuum drying step may be performed multiple times. No matter where in the entire production process the vacuum drying step is inserted after the steaming step, the effect of preventing oxidation and preserving the green color of the tea leaves can be obtained to some extent. however,
It is most effective immediately after the steaming process.

In addition, although the above embodiment describes the production of sencha, the addition of a vacuum drying process can also be applied to the production of tencha, which requires a bright dark green color. It is possible to improve the marketability of the product. The entire traditional manufacturing process for tencha is as follows:
A steaming process, a cooling diffusion process that removes steam dew, cools the leaves and opens the folded leaves, a rough drying process that dries the tea leaves at high temperatures for a short time, a main drying process that then performs lapse rate drying, and a drying process that removes defective leaves. The process consists of a sorting process to remove dust, etc., and a kneading and drying process to separate and dry the leaves and stems, but by adding a vacuum drying process after the steaming process, the green color of the tea leaves can be maintained.

Note that, as in the case of manufacturing Sencha, a certain degree of effect can be obtained no matter where the vacuum drying step is inserted after the steaming step in the entire manufacturing process, such as after the diffusion step.

〔Effect of the invention〕

According to the present invention, since the tea leaves are vacuum-dried after the steaming process, it is possible to prevent the tea leaves from oxidation, and therefore, the bluish color of the leaves can be maintained clearly. It is possible to improve the marketability of products such as

[Brief explanation of drawings]

The drawing is a schematic illustration of a vacuum dryer used in an embodiment of the tea manufacturing method of the present invention. 1...Vacuum dryer, 2...Vacuum chamber.

Claims (1)

[Claims] 1. A tea manufacturing method characterized by vacuum drying the tea leaves after a steaming process.