Green tea: Fixed（or de-enzymed） -Rolled -Dried steamed or pan-fried to inactivate oxidase)
It is worthy to note that different kinds of green tea have different requirementsof plucked young tea shoots. The common young tea shoots required are one budand two or three leaves,一芽二三叶 while those for famous high-quality green tea are usuallyone bud and one leaf一芽一叶, even just one bud一芽.In Japan, some high-quality green teassuch as gyokuro and matcha are produced from the fresh tea leaves grown under90% shading遮荫 for 2 weeks and 40–50% shading for 1–2 weeks before being plucked,respectively. The quality of fresh tea leaves plays a key role in the characteristics ofgreen tea.
In the harvesting season, the tender tea shoots are plucked by hand or a mechanicaltea plucker and delivered to tea factories immediately. In order to prevent fermentation(the oxidation of catechins儿茶素) and formation of the characteristic “greenleaf, green liquor of green tea, the leaves are immediately fixed to inactivate theendogenous enzymes by steam or heat with pan frying, roasting, or baking. However,on the heavy harvesting days, the leaves are thinly spread out indoors in a shallow basket in the racks, or some ventilating通风的 beds like bamboo mesh mats草席，trays, troughs,槽spreading machines, and wait for fixation. The waiting time should be as short as possible to avoid oxidation, which turns the green leaf and stem to red. The tea fixationapparatus include a tea steaming machine, wood-fired pan, electrical pan, rotaryheated drum, microwave, and far infrared. When fixed leaves become soft and flaccid,they are conveyed to be rolled, and then the rolled tea masses are loosened解蒂 bya roll breaker or ball breaker and moderately cooled. Subsequently, the leaves arefired (dried) by charcoal-fired baking baskets, electrical heaters, coal heaters, liquidpetroleum gas heaters, or natural gas heaters. The moisture content of the final product (crude tea) should be less than 6%.
According to the fixation ways, green tea is subdivided into steamed green tea 蒸青、pan-dried green tea炒青、roast-diried green tea烘青and sun-dried green tea晒青. Steamed green tea is mainly produced and consumed in Japan, while pan-dried green tea is mainly produced in China and exported to the world.Crude green teas are usually refined by the wholesale tea dealers. The refiningprocess generally includes sifting筛分, cutting切削, grading分类, refiring复火, polishing磨锅抛光, blending拼配, and packing包装. Through refining, the stalks, dust, and impurities are removed. The final tea has a uniform size and standardized appearance, such as Chunmee珍眉, Sowmee秀眉, and Gunpowder珠茶Chunmee and Sowmee are renowned for their curve shape, like the humaneyebrow, while Gunpowder is featured with tiny, tight, round balls like gunpowder.