According to the mature state of modulated tobacco leaves, the maturity is divided into five levels: complete maturity, mature maturity, mature maturity, immature maturity and false maturity, which are introduced below respectively. Fully mature: refers to fully mature tobacco leaves, which are born above the middle of the tobacco plant. Due to high maturity and high consumption of internal components, the leaf structure of this kind of tobacco leaves has been loose, with low oil content, dry leaf quality, wrinkled pages, mostly orange-red and reddish-brown, obvious mature spots, often accompanied by red star spots, and outstanding smell. B. Maturity: The tobacco leaves are fully developed, have reached full maturity or full maturity, and have the quality characteristics of basic colors. Leaf cells become sparse, that is, the cell porosity is large. C, still cooked: medium cooked. Tobacco leaves are fully developed, but just mature, lacking mature quality characteristics. Due to the slow decomposition of chlorophyll, it is easy to appear blue-yellow smoke when the temperature rises inappropriately. D. Immature: the lowest degree of maturity. Mostly refers to bluish yellow or undeveloped tobacco leaves, which do not have the quality characteristics of mature leaves. E. false ripening: only appears in the foot leaves. Due to the lack of nutrients and sunshine, the lower tobacco leaves are not mature, but they are mature. So it's called fake cooking.