A Tour of a Tea Production Plant in Japan
Immediately after picking, the leaves are brought to the factory for preliminary processing.
Quality of the finished green tea depends on good tea leaves; however, rolling techniques are also a critical element.
Rolling The Tea at "Body-Temperature"
When teas were rolled by hand, it was said that the optimal temperature for rolling tea was the body temperature. In fact, tea which is around 36 degrees C., turns 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. The rolling temperature is automatically controlled once the temperature is set. However, the tea master will touch the tea with his own hand to make sure that it feels right.
Because fresh tea leaves brought to the factory cannot be processed all at once, they are stored in a Pre-server until the roller is available to process them. If the leaves were just left in the Pre-server, they would begin to heat up and deteriorate. To avoid this, a fan blows on the leaves to keep the quality at its best.
Steaming determines quality of the tea. It requires skill and experience to adjust the steaming machine according to leaves' condition and weather.
The steaming process has two purposes:
To stop the oxidation of the tea leaves.
To produce a specific type of tea depending on the length of steaming.
There are two types of steaming machines, the revolving steaming machine and the belt-conveyer steaming machine. The complete process takes a maximum of two minutes
Primary Tea Rolling Dryer
With heated air blown in, the tea leaves are dried while the dryer's spindle rolls 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.
This process is monitored to produce the aroma of the green tea and takes about 45 minutes.
Next, the leaves are rolled under slight pressure to remove the moisture inside the leaf.
As moisture levels vary from leaf to leaf, the primary purpose of this process is to achieve a uniform moisture content in all the leaves. The process is conducted at the room temperature without heated air and takes about 25 minutes.
Secondary Tea Rolling Dryer
Next, the leaves go to the secondary tea rolling dryer. They are rolled in the revolving round dryer and dried to the certain level becoming round in shape. This process lasts about 40 minutes
Final Tea Rolling Dryer
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 into tiny round shapes under slight pressure.
The needle like shape of typical Japanese green tea is achieved during this process. This stage takes about 40 minutes.
For proper 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 to 5% moisture content. This stage takes 30 minutes.
Tea Refining Machine
Taken out of the dryer, the tea is sifted to remove stems and other debris.
Different teas may be blended together and temporally stored. Then samples from the storage are presented to a wholesaler for pricing. The tea is packed in 30 kilogram units and delivered to the wholesaler where it will undergo further selection.