This article covers breast milk storage guidelines and how to reheat and use breast milk. The source for these guidelines is a combination of the Department for Health and Human Services (Centers for Disease Control and Prevention) and the American Academy of Pediatrics.

Storage Containers for Breast Milk
The best storage device for breast milk is normal baby bottles or specialized milk storage bags. The easiest way is to store breast milk that will be used the same day in a standard baby bottle and if the breast milk will need to be stored for a longer period of time, use the storage bags in the freezer. This way you have bottles ready in case you need them and the bags are easier to defrost.



How to Store Breast Milk

• It is best to store breast milk in 2-5 ounce servings (depending on how much you baby normally drinks, store in serving size amounts). This way you are only heating the milk you will be using.
• You can combine breast milk from different pumping sessions into one bottle or storage bag.
• Be sure to date each batch and use or throw away before it expires. (See chart below for expiration).
• Breast Milk should be frozen within two days of pumping. When freezing, leave room for expansion in the bottle or bag. (Do not refreeze breast milk.)

Breast Milk Storage Lengths & Expiration

Breast Milk at Room Temperature:

• Up to four hours at 80 degrees F
• Up to 10 hours at 70 degrees F

Breast Milk in a Cooler with Ice

• Up to 24 hours (at 60 degrees F)

Breast Milk in the Refrigerator:

• Five days (39 degrees F)

Breast Milk in the Freezer:

• Two weeks in a freezer of a refrigerator
• Six months in a deep freezer at a constant 0 degrees F

Heating, Thawing and Reusing Breast Milk

How to Heat a Bottle or Thaw a Breast Milk Storage Bag

If the bottle is already at room temperature you do not need to heat it.

Heating a bottle from the Refrigerator:



1. Fill a bowl with water
2. Heat water in microwave, 2 minutes 30 seconds.
3. Place bottle in hot water for 30-60 seconds or until room temperature.
4. Swirl
5. Test temperature on inside wrist. Should be body temperature not hot.

(Use can also use a bottle warmer. )

Thawing breast milk storage bag from the freezer:
1. If time permits place bag in refrigerator to defrost and then heat according to the instructions above. This typically takes 12 hours so you may want to put it in the night before you need it.
2. If time does not permit thawing in a refrigerator run under warm water or swirl in a bowl of warm water until it is defrosted and room temperature.
3. Avoid letting milk sit at room temperature to thaw.

Learning curve makes this contraption which helps to thaw breast milk storage bags:




Commonly asked Questions about Breast Milk Storage:

1. Can I microwave breast milk? No. Microwaving breast milk can remove some of the anti-infections properties and nutrient qualities in the milk or create hot spots which can burn your baby’s throat. The same goes for heating directly on the stove.
2. If my baby doesn’t finish the milk at one feeding can I reuse it for the next feeding? Opinions on this are mixed. I do it. Just be sure not to refreeze the milk after it has been thawed.
3. My breast milk looks weird after refrigerating. Is it bad? The fat in the milk will separate when refrigerating. This does not mean the milk has gone bad. Just swirl it to mix it together again.