Because of the many benefits of breast milk, working mothers may go to great lengths to ensure that their baby is fed breast milk when they are away. To offer adequate support to nursing moms and to ensure that the nutrients of the breast milk are protected, nannies must be knowledgeable about handling, storing, defrosting and serving breast milk.
According to La Leche League International, properly expressed milk can be stored at room temperature for up to 6 hours (4 being ideal) and it can be refrigerated for up to 8 days (72 hours being ideal). If it is not going to be used within that time frame, it should be poured into a clean, BPA free plastic nursing bag or glass or hard plastic container, sealed and placed into the freezer.
If the freezer is part of the refrigerator with a separate door, the milk should be used within 3 to 6 months. Milk stored in a separate deep freezer can be stored for six to twelve months. La Leche League International recommends placing the milk in the back of the freezer where the temperature is most consistent.
Frozen expressed milk should be thawed by placing it in the refrigerator overnight or by running it under cool water. Increase the temperature of the water to get the milk warm enough for feeding. Alternatively, containers of frozen breast milk can be thawed by placing them into a cup or bowl that has been filled with heated water. Thawed milk should be used within 24 hours and should not be refrozen.
La Leche League International states there is no research about whether freshly expressed milk left unfinished at room temperature should be discarded, or can be saved for a short time, perhaps up to one hour. Nannies should consult with the parents regarding the feeding of unfinished breast milk.
And while you can add freshly expressed breast milk to refrigerated or frozen milk expressed earlier in the same day, the Mayo Clinic advises that you should thoroughly cool the freshly expressed breast milk in the refrigerator or in a cooler with ice packs before adding it to previously chilled or frozen milk. Warm breast milk should also not be added to frozen breast milk as warm breast milk will cause the frozen breast milk to partially thaw.
Avoid using a microwave oven to warm expressed breast milk. Microwave heating may cause some hot spots in the milk that can burn the baby’s mouth. Microwave heating may also destroy some beneficial properties of the milk.