Breast milk provides comprehensive nutrition and immune support for infants, making its proper handling and storage a significant consideration for parents. Many caregivers have questions about how to safely store and prepare expressed milk to maintain its quality and beneficial properties. Understanding established guidelines helps ensure the milk remains safe for consumption.
How to Safely Combine Breast Milk
You can add freshly expressed breast milk to already refrigerated milk, but careful steps are necessary to ensure safety. The key principle is to cool the freshly expressed milk to the same temperature as the refrigerated milk before combining them. This prevents the warmer milk from raising the temperature of the already cooled milk, which could encourage bacterial growth.
To achieve this, pump the fresh milk and allow it to cool to room temperature. Afterward, place the cooled fresh milk in the refrigerator for about 30 minutes to match the temperature of the milk already stored there. Once both milks are at the same temperature, they can be poured into the same storage container. If combining milk expressed on different days, the storage duration should be based on the date the oldest milk was first stored.
General Guidelines for Storing Breast Milk
Proper storage conditions are important for maintaining breast milk quality. Freshly expressed or pumped milk can be stored at room temperature (77°F or colder) for up to 4 hours. For refrigeration, breast milk can be safely kept in a refrigerator (40°F or 4°C) for up to 4 days. For longer storage, freezing is an option; breast milk is typically used within 6 months, but can be stored for up to 12 months in a freezer (0°F or -18°C or colder).
Containers for breast milk should be clean, food-grade, and have tight-fitting lids. Options include BPA-free glass or hard plastic containers, or special plastic bags designed for milk collection and storage. Label each container with the expression date. When freezing, leave about an inch of space at the top of the container because breast milk expands as it freezes. Storing milk in smaller portions, such as 2 to 4 ounces, can help prevent waste.
Common Mistakes to Avoid When Handling Breast Milk
Avoid common practices that can compromise breast milk safety and quality. Thawed breast milk should not be refrozen once fully thawed; however, if ice crystals remain, refreezing is possible. Once thawed milk is brought to room temperature or warmed, it should be used within 2 hours.
Do not microwave breast milk; it creates hot spots that can burn a baby’s mouth and degrades nutrients. Leaving milk out beyond 4 hours at room temperature allows for bacterial growth. Overfilling storage containers for freezing can lead to leaks or damage due to milk expansion. Unsterilized equipment or containers not designed for breast milk (e.g., disposable bottle liners, general plastic bags) can introduce contaminants. If a baby does not finish a bottle, any leftover milk should be discarded within 2 hours.