The occasional appearance of sourness in the mouth when eating is caused by having just eaten sweets, and the persistent appearance is related to excessive secretion of stomach acid. Some people occasionally show a sour feeling in the mouth when eating, which is directly related to just after eating sweets. Sweet food contains a large number of lactic acid bacteria will appear sour taste after being fermented by the body intake, so the appearance of sour mouth after eating sweets is a normal phenomenon. But there are some of the phenomenon of mouth acidity is persistent, these people should be alert to be caused by excessive secretion of stomach acid. If you don’t take care of your stomach and eat food that stimulates the stomach mucosa, the stomach mucosa will be damaged and the gastric glands will secrete too much stomach acid.