Vinegar over time is not always edible. Whether vinegar can be eaten after a long time is mainly based on the appearance and the expiration date on the label. From the outside, if the vinegar has sediment, color change, even if it has not exceeded the shelf life can not be eaten. After the expiration date, even if there is no change in appearance, it is not recommended to eat it. If the vinegar is still within the shelf life and there is no change in appearance, you can eat it. Vinegar is a good frying seasoning, sour flavor, raw materials are glutinous rice, wheat, sorghum, corn, bran, rice, etc., rich in free amino acids, acetic acid and other organic acids. In cooking with vinegar, make the flavor of the dish more delicious, vinegar can also be blended with a variety of coleslaw and so on. If you have excessive stomach acid secretion, it is recommended that you do not eat or eat less vinegar. If you eat vinegar after the occurrence of abdominal pain and other adverse reactions, it is recommended to seek medical attention in a timely manner.