Breast Milk Storage

The following are breast milk storage guidelines for healthy term babies. The numbers listed in the chart are maximum hours or days that breast milk can be safely stored at different temperatures.


Freshly expressed breast milk

Thawed breast milk (previously frozen)

Room temperature

4 hours at 66-72F (19-22C)

Do not store; throw away

Cooler with frozen ice packs

24 hours at 59F (0-4C)

Do not store; throw away


5-7 days at 32-39F (0-4C)

24 hours

Stored in the freezer of a self-contained refrigerator / freezer unit

3-6 months at 1 to 32 F

Never refreeze thawed milk

Deep freezer

6-12 months at 0F (-19C)

Never refreeze thawed milk

Warming/Defrosting Breast Milk

When the refrigerator or freezer are used for longer term breast milk storage, there are guidelines to follow when defrosting and warming prior to feeding.

  • Breast milk in a container or bag that comes from the refrigerator can be placed in a bowl of warm water or under warm running water.
  • Frozen milk can be placed in the refrigerator the night before you are going to use it. It takes about eight to 12 hours to thaw. Once it is defrosted in the refrigerator, it must be used within 24 hours. By using this method, you can divide the portions of thawed milk and store the remainder in the refrigerator for 24 hours. Never refreeze breast milk.
  • Place container of thawed or frozen milk in a bowl of warm water or put it under warm running water. Do not use hot water or the microwave as this can destroy some of the milk’s properties.
  • Fat will rise to the top of the breast milk. Gently swirling the container will mix the separated milk. Don’t shake breast milk.
  • Breast milk should be used within one hour after warming. Discard any breast milk you don’t use during a feeding.