The best thing to do is not to give your baby any more milk powder after a month of opening. After opening the milk powder should be eaten as soon as possible within one month, can not be retained for a long time, because after opening the milk powder does not belong to the sealed preservation, will come into contact with the outside air bacteria, etc., there may be the problem of deterioration of the milk powder, consumption may cause indigestion, diarrhea, and other diseases, also the child’s growth and development caused by the impact. The shelf life of most milk powder is 18-24 months. Different manufacturers and brands may have different regulations. After opening the milk powder should generally be kept away from light and moisture, too high or too low temperature will affect the quality of milk powder. It is usually better to keep it at home in a cool and dry environment to prevent the milk powder from caking in moisture and harboring bacteria. So it is recommended that if the baby’s appetite is small, you can buy a can of milk powder or a small can of milk powder in a small independent package, so that you can avoid the problem of the baby’s illness due to the deterioration of milk powder.