Processing Different Types of Tea
Tea can be divided into three categories according to processing method: non-oxidized (green tea), semi-oxidized (oolong tea), and oxidized (black tea). All are produced from the same tea plant (Camellia sinensis), part of the evergreen Theaceae family.
Green tea (ryokucha) is consumed on a daily basis in Japan. Oxidation (commonly referred to as “fermentation”) is halted by applying heat to the freshly picked tea leaves, which are steamed, then cooled while removing moisture. The leaves are dried in hot air, then pressed to equalize the amount of leftover moisture. The drying and pressing process is repeated until the leaves retain only 5 percent of their original moisture.
Types of Green Tea
Matcha, the powdered tea used in the tea ceremony, is made with tencha, tea grown and prepared for making matcha. Tencha leaves are crumbled into pieces 3 to 5 millimeters in size before grinding them down to powder in a stone mill. Another type of powdered tea, konacha, is made from tea dust, buds, and small leaves left over from processing sencha, the most common type of tea grown in Japan. Sometimes confused with matcha, konacha is typically used in cooking and as an inexpensive tea offered at sushi restaurants.
The highest grade of green tea is gyokuro. Though processed like other teas, gyokuro leaves have been shaded from sunlight for at least two weeks before harvesting.
The most common tea produced in Ureshino is tamaryokucha, a tea characterized by its curved, coiled leaves. Ureshino also produces kamairicha, a tea with a light roasted flavor that is achieved by a method similar to the traditional Chinese style of pan-roasting the leaves at 300°C.
Black Tea
Black tea is tea that has undergone oxidation. Harvested leaves are left to wilt naturally and then dried after they turn brown. Black tea leaves are not as stiff as those of green tea. Once dried, the leaves are pressed, then sieved to loosen clumps, a process that lasts between 2.5 and 4 hours. The leaves are then further dried by applying hot air until the residual moisture content is reduced to around 3 percent.
Oolong Tea
Oolong tea is “semi-oxidized,” making it an intermediate choice between green and black tea. To produce oolong tea, fresh leaves are initially exposed to sunlight for one hour until they begin to wilt and turn a reddish-brown color. The leaves will also start to exhibit a strong, fragrant smell. Next, high heat and pressure are applied to halt the oxidation process. The leaves are then wrapped in moist cloth for 10 to 20 minutes to soften them. Finally, they are shaped and dried.