Green Tea Processing Method

Today sencha tea leaves are cultivated in the warmer southern regions of Japan. In 1998, Japan produced 82,600 metric tons of green tea. Nearly half of all tea produced in Japan comes from Shizuoka prefecture, but production has recently increased in Kyushu.

In the Tea fields on Makinohara upland, Shizuoka prefecture - Fans are set up on the poles to protect the fields from frost.

Growing

Wild tea plants grow tall*, but cultivated ones are pruned to keep them at around 1 meter (3.3 ft) high in order to produce small and tender leaves. Only young leaves are harvested from the bush to make good sencha tea.

Chinese camellia can grow as high as 4 meters (13.1 ft) in the wild.

Young leaves of the tea plant for sencha tea, Camellia sinensis or Chinese camellia

After harvesting, regular tea leaves are processed with machines specially designed to steam, roll and dry them. Tea leaves soon ferment and turn brown so in Japan they are generally steamed to prevent this. This is the method unique to Japan.

The steaming method was allegedly introduced by the Chinese monk Yinyuan (Ingen in Japanese) in the seventeenth century. In these areas, the leaves are heated, crumpled and heated again before being finally dried. This produces a tea with a yellowish tint which is less astringent than the regular sencha tea because the leaves are wadded and turn an ashy-green color. One such area is Ureshino in Saga prefecture.

Gyokuro (top-grade sencha) tea leaves are cultivated with special care*, and only the top parts of the leaves (1 bud and a few leaves) are harvested. In some areas they are picked and rolled by hand into tiny, needle-shaped pieces on a special drier.

*The bushes are sheltered from the sun rays by covers to increase the sweetness for a few weeks before harvesting.

Harvesting

Today, tea leaves are usually cut off from tea bushes with shears or reaping machines and the processing of tea leaves is mostly automated.

Tea leaves are harvested in a cycle; the first tea leaves are collected in May, the second tea leaves in June, and the last tea leaves in August. Click here to see the tea cultivation cycle in detail.

To stop fermentation, the harvested tea leaves are generally steamed. This sterilizes the actions of digestive enzymes in the leaves. The green color of the leaves is retained and they are softened, making the next process easier.

Rolling

The steamed leaves are rolled into tiny, needle-shaped pieces in stages, in which the tissues of the leaves are broken and the juices are liberated so that the flavor of tea draws out well in hot water.

This task is mostly done by machine

The steamed tea leaves are first picked up and loosened on a hot tea drier*. This action is repeated to allow the moisture to evaporate evenly.

*The drier is a billiard-table-shaped device heated from underneath by a charcoal fire. Thick washi paper is spread on the surface and acts as a filter.

Some teas are still finished by hand

Rolling

The tea leaves are rolled from side to side and pressure is applied to break the leaf tissues.

Rubbing

The leaves are rubbed hard between the palms until rounded.

Pressing

The rounded leaves are pressed on the drier with the right and left palms in turn to make them thinner.

Shaping up

The thinly rounded leaves are finally shaped into needles by grasping and rolling with the right and left hands in turn. Well-thinned leaves take on a lustrous sheen when sufficiently dried.

Drying

The leaves are then transferred to another drier for a final drying at a low temperature. The leaves are finally dried out ( to dark greens). Regular tea leaves are dried artificially with warm air while gyokuro leaves are dried naturally in the sun. Drying preserves the leaves.