How long can expressed or pumped breast milk be safely stored? Here are some guidelines.

Room Temperature
Fresh milk 4-8 hours
Thawed milk 1-4 hours
Refrigerator
Fresh milk 3-5 days
Thawed milk 24 hours
Freezer
Upright freezer (attached to a refrigerator) 3-6 months
Chest or deep freezer 6-12 months

General guidelines

  • Milk should be stored in 1-4 ounce portions.
  • Several expressions or pumpings in one day may be combined.
  • Date each bag of milk before storing.
  • Do not store on the door of the refrigerator or freezer. Store inside towards the back.
  • Do not refreeze thawed milk.
  • Milk will separate into liquid and cream. Do not be surprised or alarmed!
  • Milk will often appear bluish or other tints of color. It is not bad or spoiled unless it smells or tastes sour.
  • Milk not finished at one feeding can be saved for the next feeding only, then it should be discarded.

Thawing milk

  • Milk can be thawed in the refrigerator; it takes about 12 hours.
  • Milk can be thawed faster by placing it in or under warm water or by using a bottle warmer.
  • Milk should not be left at room temperature to thaw.
  • Milk should not be thawed in a microwave or on the stove. This destroys some chemicals in the milk and can overheat the milk as well.
  • Milk can be swirled or very gently shaken if it has separated.
  • Always check the temperature before feeding it to the baby.

Resources

Proper Storage and Preparation of Breast Milk (CDC)

References

Eglash A, Simon L, Brodribb W, et al. ABM Clinical Protocol #8: Human Milk Storage Information for Home Use for Full-Term Infants, Revised 2017. Breastfeeding Medicine. 2017;12(7):390-395. doi:10.1089/bfm.2017.29047.aje Available for free here.