Breast Pumping

In this section is detailed information on the recommended types of containers to store breast milk, the volume of breast milk to store in a container, and labeling stored milk. Be sure to check out our Milk Storage Guidelines that includes a Milk Storage Chart.


  • Glass or hard plastic BPA-free containers with leak-proof lids can be used.
  • Breast milk freezer bags are also an option.
  • Avoid sandwich bags or thin disposable feeding bottle liners that can split when frozen. These type of liners are meant to be used as bottle feeding bags, but not for freezing milk.
Breast Milk Storage Bags

How Much to Store in a Container

  • Store your milk in the smallest amount your baby might take. When your baby takes a bottle, her saliva mixes with the milk. You can always add more milk to a bottle during a feeding if she wants more, but don’t save the leftover milk once the bottle has been in your baby’s mouth.
  • If freezing your milk, always leave room for expansion. Just like any liquid you freeze, milk expands too, so do not fill up to the very top of the container.
  • You can combine milk pumped at different times. Chill freshly expressed milk before adding to already frozen milk. When combining milk from different days, write the date of the oldest milk on the container.
Breast Milk Storage Bottles

Labeling Stored Milk

  • Write the date and time on your milk container using a sticky label or non-toxic marker. Add your baby’s name if your baby is at a facility that cares for other babies or toddlers.

This is general information and does not replace the advice of your healthcare provider. If you have a problem you cannot solve quickly, seek help right away. Every baby is different. If in doubt, contact your physician or healthcare provider.