Storing expressed breast milk

Q: I’m nursing my newborn and want to give her expressed breast milk when I eventually go back to work. What’s the best way to store breast milk, and how long can it be at room temperature before I have to throw it out?

A: Clinicians at the Mayo Clinic in Rochester (mayoclinic.org) recommend the following for the handling and storage of breast milk:

Room temperature: Freshly expressed milk can be kept at room temperature for up to six hours. If you believe it’s going to be longer than six hours, consider placing it in a refrigerator, freezer or even an insulated cooler.

Refrigerator: Place freshly expressed milk in the back of the refrigerator, where it’s cooler. It can be safely stored for five to eight days, depending on the average temperature of your refrigerator. It’s best not to store it in the door, because temperatures tend to be higher.

Freezer: The back of freezers in standard refrigerator-freezer models can safely store freshly expressed milk for three to six months. Chest-type freezers can store it for six to 12 months reliably.

Coolers: Insulated coolers with ice packs can provide temporary storage of expressed milk for up to one day. Transferring it to a more permanent location is good to do as soon as reasonably possible to ensure freshness.