Jin Junmei is a fully fermented black tea with a shelf life of 2 years. Jin Junmei, which exceeds the shelf life, is prone to oxidation reaction with air, which leads to the loss of beneficial substances in tea and may produce spoilage bacteria, posing a threat to health. Although the water content of dried tea is extremely low, dry tea is not easy to go moldy and deteriorate even if it exceeds the shelf life under dry and sealed storage. However, if the quality of tea is poor and the water content is higher than 2%, it is not recommended to drink it again. For Jin Junmei, which has been placed for 78 years, it is recommended not to drink it, because its quality and moisture content cannot be determined.