PURPOSE: Burnt alum and a sweetening are added to canned sweetened persimmons, thus preventing them from becoming astringent again during the storage.

CONSTITUTION: A sweetening such as sugar or glucose is stirred together with water to make a syrup, which is combined with burnt alum and citric or tartaric acid, and they are heated. In an example, 500g of sugar and 500g of glucose are combined with water in a vessel to make 3l of solution. 12g of citric acid and 1g of burnt alum are added to the solution and they are stirred. Then, the vessel including the solution is heated and the boiling is continued for 10min. The solution is gradually cooled until it becomes 50°C. The resultant syrup is poured into a bottle including sweetened persimmons. Without lidding, the vessel is heated in hot water kept at 85°C and it is taken out of the hot water, when the content becomes 65°C, then, sealed.