Try not to fill the bag too much, as the milk expands during freezing. It’s generally best to fill the bags to the guidelines of the manufacturer, but it’s OK to do a little more or a little less. Just make sure that the bag isn’t completely full with raw milk, as there will be a much greater risk for leaks.
Squeeze the air out of the bag as best you can before sealing.
To freeze flat, you can lay the bag on the shelf in your freezer, or even in the door on the side. Whatever flat surface works best for you. Once the milk is solid, you can move it to a different location in your freezer. IMPORTANT: Breastmilk should not be stored in the door of a freezer unless you plan on using it yourself in the very near future. The door is exposed to the warm air every single time it is opened, reducing the freezer life of the milk. Laura only put the milk in her door to freeze it flat. Once it was frozen, she put it deep in her freezer for storage.
To make things easier for you, it’s a good idea to keep a list of how much milk you have frozen. This way, you don’t have to count it over and over again. Some moms keep a piece of paper on their refrigerator or in a notebook to keep track.
Breastmilk is good for up to 6 months in the freezer that is attached to your refrigerator, or up to 12 months in a deep freezer.