Glass or hard plastic containers are the best storage containers for breast milk, especially if it is to be frozen and stored for weeks or months. Freezing may cause the seams of disposable bags created for bottle feeding to split, but double-bagging may prevent this problem.
“If using bags, squeeze the air from the top before sealing tightly with a twist-tie or other clamp, and fasten the clamp at least one inch beyond milk level to allow for expansion with freezing,” advises lactation consultant Pat Wynn. Wynn also suggests placing bags upright in another container or the milk might leak out.
Fresh breast milk contains the most active protective properties, followed by refrigerated and then frozen breast milk.
Wynn has several recommendations regarding storing milk:
- Store only two to four ounces per container.
- Label each collection container with the date and any medications you have taken.
- Storage guidelines may be different for premature or high-risk infants. Consult your lactation consultant for specific instructions.
- Unrefrigerated fresh milk may be left at room temperature, but it must be used within eight hours.
- It is better to refrigerate fresh milk when it is not going to be used within 60 minutes.
Milk can be frozen for approximately:
- Up to two weeks if the freezer compartment is within the refrigerator. (You must open the refrigerator door to reach the freezer with this model.)
- Three to six months in a freezer that is part of a refrigerator unit but has a separate door.
- Six to 12 months in a deep freezer.
To keep milk cool when a refrigerator is not immediately available, or to transport refrigerated or frozen milk, place it in an insulated bag or cooler with a frozen cold pack.
Thawing Breast Milk
The following are general guidelines for thawing frozen breast milk:
- The oldest milk should be used first, unless recently expressed milk is recommended.
- Thaw breast milk by placing the collection container in the refrigerator for several hours or overnight.
To thaw more quickly or to heat refrigerated milk, Wynn suggests holding the container of milk under warm running water or placing it in a bowl of warm water. Do not thaw milk in very hot water or in the microwave. This decreases some of the healthy properties of the milk. It can also create hot spots that may burn your baby's mouth.
It is normal for milk to separate during storage. To re-combine the cream with the rest of the milk, gently swirl the bottle. Avoid vigorous shaking.
Do not refreeze milk once it has been thawed. Thawed milk must be used within 24 hours.
Our board-certified lactation consultants are available to answer questions and for in-person consultations. Call 706.509.6555 or
email us to learn more.