Breast milk should be stored at room temperature in a sterilized bottle. Alternatively, you can store it in the refrigerator for 4 days, and in the freezer, you can even store it for a month. Thawing breast milk is very important before feeding. Leave the frozen milk at room temperature and feed it to your baby once the milk is a t room temperature. You should feed this thawed milk to your baby within 2 hours, or it must be thrown away.