Question

What's the best way to store breast milk for my 7-day-old newborn? How long can you keep it in the refrigerator and how long can you keep it out? Can you mix cold breast milk from before with fresh milk expressed now and put it in the refrigerator?

Answer

I admire you that you are so successful breastfeeding that you can start pumping and storing milk this early. Your question is important, because although breast milk is certainly the best food for infants, contaminated breast milk certainly is not.

The best plan is to store breast milk in the refrigerator for up to 72 hours, or to freeze breast milk at minus 20 degrees centigrade or 0 degrees Fahrenheit for 3 days to a month.

After removing breast milk from the refrigerator or freezer, throw out any that's left after a feeding. Don't add fresh milk to stored milk. If you have freshly expressed milk and want to add it to rewarmed milk to use immediately, that is all right just for that one feeding, but again throw out any leftovers.