Mume is a kind of preserved fruit, which is a pickled product of plums. The method of plum sauce is to wash the ripe plums with salt, then add starch, stir constantly, then put the plums in the pot, boil them with strong fire, and then turn to low heat for about 10 minute until the skin of the plums breaks, and take them out. Remove the core from the plums, then continue to cook the plum sauce with low heat, keep rolling, cook until it is sticky, and cool.