What are the characteristics of Yue Hong congou?

Fermentation is the key link to form the quality of Yue Hong congou tea. In this process, a series of chemical changes have taken place in tea, which made the green leaves turn red and formed the unique color and fragrance of black tea. After kneading, put the twisted leaves in a bamboo frame for fermentation. The key factors in the fermentation process are temperature, humidity, ventilation conditions and leaf spreading thickness. In the process of fermentation, the contents in tea are released by oxidation, and the leaf temperature rises, so it is normal that the indoor temperature is around 25℃ and the leaf temperature is 2-6℃ higher than the temperature. When fermenting, if the temperature is too high, the contents will react violently, and the crude tea has low aroma, light taste and dark color. If the temperature is too low, the fermentation time will be prolonged, and the chemical changes of color and aroma of black tea will be unbalanced, which will affect the quality. Therefore, cooling measures should be taken in hot season, and when the temperature is too low in spring, the leaf layer should be thickened to facilitate heat preservation, and heating measures should be taken when necessary. When fermenting, it is necessary to maintain a high humidity state, and the relative humidity is required to be around 95%, so it is necessary to spray water or water frequently. A lot of gas is consumed in the fermentation process, and the air in the fermentation site should be fresh and circulated. At the same time, when spreading the tea leaves, it is shaken loosely and not pressed tightly. During fermentation, it should be stirred once or twice to facilitate ventilation. The leaf spreading thickness is closely related to leaf temperature and ventilation conditions, and is generally 8- 12 cm. Thick when the temperature is low, thin when the temperature is high. Young leaves and leaflets should be thinned, and old leaves and big leaves should be thinned. During the fermentation process, the color and aroma of leaves gradually changed until the fermented leaves were copper red, and the fermentation was moderate when apple aroma appeared. If the fermentation is not sufficient, the dry tea will be green, uneven in red and green in red, which is called "flower green" in tea evaluation terminology; If it is excessive, the aroma is low, the taste is light and the leaf color is dark.