Tea begins to ferment soon after it’s been picked due to the influence of oxygen. Japanese tea is non-fermented, which is why tea farmers work to process tea to a certain extent on the very day it’s picked. Tea made in this manner is known as crude tea. Processors in the business of finishing tea will buy tea from farmers as crude tea, and then undertake the final finishing process at factories or co-ops.
Here I’ll tell you about how crude tea is made.
The goal of the process for making crude tea is to finish the basic shaping of the leaves, and to dry the leaves to about 20-40% of their weight (23 kg of crude tea for every 100 kg of tea, to allow for easy storage. Crude tea is a half processed product, which doesn’t yet have market which is why it must then undergo the finishing process to become a product.
Normally hand-picked Sencha, singles sprouts of two to three leaves are picked, and for machine-picked sencha, sprouts four to five leaves are picked. Leaves which have just been picked are still alive and respirating, which is why they generate heat.
2. Airflow and Heating
If freshly picked leaves are left alone, fermentation will quickly begin, heating the leaves. This is why, in order to protect the freshness, and prevent the quality of the tea from lowering, high temperature air is sent around the leaves, which lowers the amount of moisture they hold, as well as heat generated by the respirations of the leaves.
In order to stop oxidase activity, and to protect the color of the tea leaves while reducing their ran scent, the leaves are steamed evenly with steam. The length of time for steaming here will determine the basic qualities of taste, scent, and brewing color for the tea.
The steam is a deciding factor in the color and quality of Rokucha, ad the longer the tea is steamed, the more the cells of the tea leaves will be destroyed, and the muddier the color of the brewed tea will become, while the color and luster of the tea will become brighter.
If the steamed tea is left at a higher temperature, the bright color will be lost, and the flavor of the tea will be degraded. That’s why air is sent through to cool the tea, and the tea is quickly cooled to around room temperature in order to protect the color and luster, and fragrance and taste of the tea leaves.
5. Leaf Pounding
In order to improve the color and luster, and fragrance and taste of the tea leaves, the process of massaging the leaves will be conducted in a time saving manner, but applying pressure to the leaves as a dry, hot wind is blown through them (this also dries off water on all sides of the leaves).
6. Sojyu, the 1st Rolling Process
In order to soften the leaves and lower their internal moisture content, pressure is applied while dry hot air is sent through the leaves, and friction and pressure are applied again and again to massage the leaves.
7. Junen, the 2nd Rolling Process
In order to prevent under-massaging in the previous step, and to break up the structure of the tea leaves, make it easier for the various compounds to be extracted during brewing, and ensure the even distribution of moisture, the tea leaves are brought together into one ball, before pressure is again applied (this time without heat) to massage the leaves.
8. Chuju, the 3rd Rolling Process
After the previous step, the tea leaves have shrunk and their shapes are again uneven, and they also still contain quite a bit of moisture, which is why pressure is again applied to massage the leaves, while passing hot, pressurized air through the leaves. The leaves are broken apart, and given a twisted shaped, before being dried for shaping in the next step.
9, Seiju, the 4th Rolling Process
In order to shape the Rokucha in its distinctive long, slim shape, the leaves continue to be dried to pull out their internal moisture, while workers massage them solely in one direction to give them shape.
With the previous steps, the internal moisture of the tea leaves is brought down to 10% - 13%, and in this step hot air is continually blown at the tea to bring that down to 5%. This means the tea can be stored for long periods of time, and it also helps accentuate the fragrance and taste of the tea.