Breast Milk Collection & Storage

How do I keep my pumped milk fresh?

So you’ve finished pumping and collected all of that great milk! What’s next?

Once you’ve emptied your breasts, mix both right and left bottles together into one and place it in the refrigerator, cooler or ice chest. Keep in mind it may take several pump sessions to completely fill one bottle for your baby. For example, you may pump 3 or 4 separate times, each yielding anywhere from ½ ounce to 3 ounces of pumped milk. It’s ideal to pool all the milk from your various pumping sessions throughout a 24-hour period. After all the milk has cooled in the fridge, the milk should be combined and gently mixed and then poured into separate bottles of the volume you need to leave for your baby while you are away.

Place these “individual servings” in the freezer.

What’s an individual serving?

  • An individual serving is how much milk your baby consumes in one feeding.
  • If your baby is taking 3 – 4 ounces at a feeding, then you should leave as many 3 – 4 ounce bottles as you can provide from your 24-hour pumping sessions.
  • If you don’t know how much your baby is taking at each feeding (which is very common), then leave 2 – 3 ounce bottles.
    • Defrost one bottle at a time and see how much the baby requires.


Whatever the baby does not drink should be placed back in the refrigerator with a clean cover (be sure to remove the nipple) and re-warm for the next feeding. Use this milk within 24-hours.

The best location is on the center shelves closer to the back of the freezer.

  • Avoid the freezer door when storing your milk.
  • You can lay the freezer bags down or stand them up, whatever works best for you.
    • Some mommies use special trays that are similar to old-fashioned ice-cube trays to store frozen milk. Others put a number of single serving bags into a large plastic freezer bag.
  • Always mark the date and time of when you first put the milk into the freezer on the storage container.
    • Milk can be kept for quite a long time, but it’s always a good idea to keep track of the age of the milk.
    • Over-pumping can provide you with a freezer full of milk, but that may not always be the best idea unless there are special circumstances where you are consistently away from your baby during the day (i.e. NICU stays, returning to work).


Storing breast milk*

  • Freshly pumped milk can stay at room temperature for up to 6 hours. After this time the milk should be placed in a refrigerator or freezer until it is time to be used.
  • Milk placed in the refrigerator should be used within 4 – 8 days or placed in the freezer.
  • Milk can be placed in a freezer up to 6 months after being cooled under running water, but the temperature must remain stable so that the milk is not compromised

Whichever methods you choose to store your breast milk, remember to use proper storage containers, and safe locations in the fridge or freezer. Protect your milk containers from spills and other odors by making sure they are properly sealed. Breast milk is liquid gold!

*The most up-to-date information available at the time of this posting

Still have more questions about pumping and storing your “liquid gold?” Send us a message and get help from a lactation consultant on our team.

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