Freezing expressed breast milk offers flexibility for parents who pump, providing a ready supply for future feedings. This process often leads to the creation of a “breast milk brick,” an informal but widely used term among parents. This specific freezing method is helpful for building a substantial, organized supply for long-term use.
Defining the “Breast Milk Brick”
The term “brick” describes the flat, rectangular shape achieved when a breast milk storage bag is frozen properly. This shape is deliberately created to streamline the storage process. Instead of a bulky, rounded container, the milk solidifies into a thin, uniform slab. This flat profile maximizes freezer capacity and allows for dense stacking. By preparing the milk in this manner, parents can create a highly efficient freezer stash, sometimes grouping multiple individual flat bags into a larger unit for easier inventory management.
Creating the Brick: The Freezing Process
Creating the flat, brick shape requires using specialized, durable breast milk storage bags. Before filling, parents should clearly label the bag with the date and volume of the milk expressed. To ensure the milk freezes flat, fill the bag with a measured amount, typically between two to six ounces. Filling the bag to a smaller volume helps guarantee the thin profile.
A one-inch space must be left at the top of the bag before sealing, as the milk expands significantly when it solidifies. Carefully squeeze out any excess air before sealing the zipper lock to help prevent freezer burn and maintain the milk’s quality. The essential step is to place the filled bag flat onto a hard, level surface, such as a baking sheet, and then transfer the tray to the freezer. The bag must remain perfectly flat until the milk is completely frozen solid, forming the desired thin slab.
Maximizing Storage Efficiency
The flat shape enables high-density storage. Once fully frozen, these uniform slabs can be stacked vertically or horizontally, drastically reducing the space needed in the freezer. For long-term safety, the bags should be stored in the back of the freezer compartment, where the temperature is most stable. Sticking to the “First In, First Out” principle ensures that the oldest milk is used before its nutritional quality diminishes.
Expressed breast milk can be safely stored in a standard freezer for up to six months, though a deep freezer maintains quality for up to 12 months. Using the milk within the first six months is recommended to maximize its nutritional integrity. Organizing the bricks by date helps parents easily track and rotate their supply, preventing waste.
Safe Thawing and Preparation
When using the frozen milk, the brick should be thawed gently to preserve its beneficial components. The safest method is to place the frozen bag in the refrigerator overnight, which can take up to twelve hours. For a faster process, the bag can be placed in a bowl of warm water or held under lukewarm running water until thawed. Never use a microwave or boiling water to thaw or warm the milk, as this destroys nutrients and creates dangerous, uneven hot spots.
Once the milk has completely thawed in the refrigerator, it must be used within twenty-four hours. After the milk is warmed, it should be consumed within two hours. The separated fat layer, which is normal for stored breast milk, should be gently swirled back into the liquid rather than shaken vigorously. Thawed breast milk must never be refrozen, as this compromises its safety and quality.