Breast milk is often referred to as "liquid gold," and storing it safely in the freezer is very important. When freezing breast milk at home after expressing, it's generally recommended that you pour the milk in to a clean BPA-free plastic storage container or polyethylene bottle liner or simply keep it in the pump bottle.
There are many different types of containers used for storing milk, from glass to plastic to stainless steel. When selecting, think about how long you plan to store your milk. Some milk storage bags, for example, are particularly designed for freezing and can be stored flat, and then stacked, which saves a lot of space. If disposable bottle liners are used for freezing breast milk, they may require additional protection to stop leaking and contamination. If you'd like to freeze milk in harder containers, glass gives the most protection, because it is the least absorbent.
Put the expressed milk in to the container of your choice and seal with the proper lid.
You will want to leave some room when freezing your milk, as the milk expands when it is frozen. You should use a solid one-piece cap for the best seal, and hold off on tightening it until after the milk has been frozen.
Place the container in the freezer.
Pumped breast milk may be kept in a standard freezer for six months (Set yours to a level that makes your ice cream rock-hard. Most freezers reach this temperature, but if you are concerned at all, you should buy an inexpensive freezer thermometer to set your mind at ease.) It can be kept in a deep freezer for one year.which seems to offer a very space efficient approach.