Green tea is one of the unique tea categories in China. It is a non-fermented tea. It is a product made of tea tree sprouts as raw materials, without fermentation, through typical processes such as fixing, rolling and drying. The quality characteristics of green tea are "three greens" (appearance green, soup color green, leaf bottom green), high fragrance, fresh taste, clear soup green leaves are the common characteristics of green tea quality.
The green tea production and packaging process generally includes green picking, withering, fixing, rolling, drying, refining and packaging.
Picking Green
Green picking refers to the process of picking tea green. There are strict standards for the picking of tea green. The maturity and evenness of bud leaves and the time of picking are all very important links to determine the quality of tea.
Withering
After picking the fresh leaves, spread them on clean utensils with a thickness of 7-10cm, spread them for 6-12 hours, and turn them over properly in the middle. When the water content of fresh leaves reaches 68% ~ 70%, the leaf quality becomes soft and the fragrance is emitted, it can enter the degreening stage. The water content must be controlled in an appropriate amount: too low water content will lead to water loss, and the leaves will dry and die in the sun, which will cause the tea to become thin in taste; The water content is too high and there is no stirring, resulting in fresh leaf water accumulation, which will lead to bitter and astringent taste of tea.
Filler
Fixation is a key process in green tea processing. The high temperature measures are taken to disperse the moisture in the leaves, inactivate the activity of the enzyme, prevent the enzymatic reaction, and make the contents in the fresh leaves undergo certain chemical changes, thus forming the quality characteristics of green tea and maintaining the color and flavor of the tea.
If the temperature is too low in the process of fixing the green, the leaf temperature will rise for too long, which will cause the enzymatic reaction of tea polyphenols and produce "red stems and red leaves". On the contrary, if the temperature is too high and the chlorophyll is destroyed too much, it will lead to yellowing of the leaves, and some even produce coke edges and spots, reducing the quality of green tea. Therefore, for fresh leaves of different grades and seasons, there are different requirements for fixing time and temperature. We must master the principle of "high temperature fixing, combination of stuffy and throwing, less stuffy and more throwing, old leaves are tender and tender leaves are old. Fixation until the leaves are dark green in color, the leaves are soft and slightly sticky, the stems are folded continuously, the hands are kneaded into a ball, slightly elastic, the green air disappears, the tea fragrance overflows, and immediately comes out of the pot when the requirements of ripening, penetration and uniformity are met. After the pot immediately spread cool, it is best to use a fan to cool, so that it quickly emit moisture, reduce leaf temperature, prevent leaf color yellow and produce water stuffy taste.
rolling
After the killing, the tea leaves are rolled like dough. The main function of rolling is to properly destroy leaf tissue (the destruction rate of rolled leaf cells is generally 45-55%, tea juice adheres to the leaf surface, and hands feel lubricated and sticky), which requires tea juice to be easy to soak out and resistant to brewing. Reduce the volume and lay a good foundation for frying and forming. Shaping different characteristics.
Kneading is generally divided into hot kneading and cold kneading. The so-called hot kneading means that the leaves are not piled up and kneaded while they are hot. The so-called cold kneading means that after the leaves are taken out of the pot, they are spread out for a period of time to knead when the leaf temperature drops to a certain extent. The older leaves have high cellulose content, and are not easy to form strips when rolling, and are easy to use hot kneading; senior tender leaves are easy to form strips when rolling, and cold kneading is used to maintain good color and aroma.
According to the strength of rolling, it can be divided into: light rolling, light rolling made of tea into a strip shape.
Drying
The drying process of green tea is generally dried first to reduce the water content to meet the requirements of pan frying, and then fry dry. The main purposes of the drying process are: 1, so that the leaves continue to change the contents on the basis of fixing, improve the internal quality; 2, on the basis of rolling finishing, improve the shape; 3, discharge too much water, prevent mildew, easy storage. Finally, the dried tea leaves must meet the safe storage conditions, that is, the water content is required to be 5-6%, and the leaves can be crushed by hand.
Packaging