Tea leaves that are picked from the tea farm is brought to the initial tea processing factory for preliminary processing. Basically, fine quality of the green tea depends on good tea leaves; however, rolling techniques of the tea production manager is also critical element.


Rolling Tea at the "Body-Temperature"

  Since the times when tea leave were rolled by hand, it has been said that the optimal temperature for rolling tea is the body temperature. This is based on actual results that the tea rolled at body temperature, which is around 36 degrees C., turned out to be the best quality.
  The body temperature, however, slightly varies according to particular kinds of tea, location of tea farms, or time of rolling. Generally, standard temperature for the first picked tea is 34 degrees C. to 35 degrees C. and for second and third picked tea is 35 degrees C. to 36 degrees C..
  There are different methods to check the rolling temperature; for example, checking by comparing the tea leave taken out of the rolling machine with your body temperature, or using the tea thermometer, etc.
  Currently, the rolling temperature is automatically controlled by the control panel once the temperature is set. It is still important to touch the tea by your own hand to make sure that it feels right.


Green Leaf Pre-Server

  Because fresh tea leaves brought to the factory can not be processed all at once, they are stored in the storage equipment named Green Leaf Pre-server until the roller is available to process them.   While the tea leaves are stuck in the server, they start generating heat due to its own breathing. Quality of the tea leaves deteriorates by that heat and become unusable to manufacture green tea. To avoid such a case ever, the fan regularly blows the air to the leaves to keep quality at its best.


Tea Steaming Machine

  A saying "Steaming determines quality of the tea." shows, among other tea production processes, how significant the steaming process is. It requires extended skills and experiences to adjust the steaming machine according to tea leaves' condition and daily weather.
  The steaming process has two purposes; A) to stop activity of oxidase of the tea leaves and B) to choose which type of green tea to produce depending on length of steaming, whether regular green tea or deep-steamed tea. Characteristics of the finished green tea is determined by adjustment of the steaming process.
  There are two steaming machines; the revolving steaming machine and the belt- conveyer steaming machine. It takes one to two minutes to finish entire steaming process. The tea leaves discharged from the steaming machine are transferred to the Primary Tea Rolling Dryer after cooled to room temperature.
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Primary Tea Rolling Dryer 48 Minutes

  With heated air blown into this dryer, tea leaves are dried while the dryer's spindle with the hand-shaped parts is rolling to stir the leaves. During this process, the tea leaves are dried up to the point that some pressure can be placed on them in the next dryer process. (Dry base of the tea leaves reduced from 400 - 300% to around 100% after this process.)
  This process consists of two major operations. One is the tea scattering dryer process which quickly removes moisture from the surface of the tea leaves. The other is the primary tea rolling dryer process which takes out moisture inside of the leaves. As processed in the primary tea rolling dryer, aroma of the green tea is emphasized.
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Tea Roller 24 Minutes

  As rolled under pressure of some weight, moisture remained in the center of leaf tissues come out to the surface.
  Moisture level varies for different parts of a leaf or one leaf to another leaf at the end of the primary tea rolling dryer process. If you proceed to the next step just like that, unevenness of the moisture level would be extended. During this tea roller process, the remaining moisture in the leaves is distributed evenly. The process is conducted at the room temperature without heated air.
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Secondary Tea Rolling Dryer 40 Minutes

  Next, the leaves go to the secondary tea rolling dryer. They are rolled in the revolving round dryer with spinning pedal and dried to the certain level becoming round shape. This is a pre-processing for the next step.
  It is very important to take out the leaves from the dryer at the same moisture level every time.
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Final Tea Rolling Dryer 40 Minutes

  After the tea leaves are taken out of the secondary tea rolling dryer, they are separated in small portions and placed in pots. Then they are gradually rolled to tiny round shape under some weight. Typical needle like shape of Japanese green tea is made during this process. And this truly depends on the tea production managers' skills.
  Very few moisture is left in the tea leaves after this process. Now our green tea is done.
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Tea Dryer 30 Minutes

  For storage, green tea has to be dried a little more after the final tea rolling dryer process. It is spread on the caterpillar and dried slowly. Dry base is 5% after this process.

Tea Refining Machine

  Taken out of the dryer, tea is shifted out to remove stems and other debris. The whole process which starts with steaming up to here takes approximately three hours. The tea is carefully refined again by wholesalers.
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Tea Blender

  Quality of the finished tea varies depending on difference in tea leaves and other factors. Different teas are blended together and temporally stored. Then samples from the storage is presented to a wholesaler by a middleman for price negotiation. The tea is packed in 30 kilogram unit are delivered to the wholesaler next morning.


  Names of equipment in this content are under study of national and prefectural tea research associations. We appreciate Mr. Tadashi Gotoh of assisting us to create this English homepage. He is a senior researcher of Tea Production Study at Shizuoka Prefectural Tea Laboratory.


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