how long is a bottle of formula good for
Mistake #3: Keeping mixed formula out too long. Formula that is sitting out at room temperature must be thrown away after 1 hour. If it is in the refrigerator, pre-mixed formula (also called ready-to-feed formula) that is opened must be thrown out after 48 hours. Formula that you mixed must be thrown out after 24 hours. Mistake #4: Re-using leftover formula.