It is recommended that breast milk be refrigerated within five hours of pumping, used within five days of being refrigerated and thawed and used within five months of being frozen.
And it is preferred to store breast milk in the refrigerator, instead of the freezer, if possible. However, just using fresh breast milk is certainly not always possible so freezing it is perfectly fine.
If you are occasionally pumping for the random bottle for when you’re away, pump and store in the refrigerator until you have about as much as your little one will take in a bottle.
If you are not sure how much Baby would take from a bottle, heres some math to help you. Estimate the number of times he nurses in a day. Divide 25 ounces by that number. So, for instance, if he nurses 8 times, 25 divided by 8 is approximately 3 ounces per feeding. Once you have the amount you need, simply store in the freezer for up to five months!
If you are mostly or exclusively pumping, you may be up to your eyeballs in milk! Once you have the milk for the day in your baby’s bottles, you can begin stashing in your freezer. Fill the storage containers and freeze for up to five months.
Freezing Breast Milk — The Details
Experts say that you should be able to use the whole progression of storage for your milk. For instance, if your pumped milk is out on the counter five hours, you should be able to then store it in the refrigerator for five days and then freeze it for up to five months (though if it’s a separate deep freezer you may be able to use it from six to 12 months after the date of expression).
Be sure to rotate your stock. Since it’s best to use fresh milk (most of the leukocytes are destroyed during the freezing process), you can use up the freshly pumped breast milk and pull out from the freezer a container of frozen milk as needed. The next time you pump, you can then replace the milk just used.
Lay the storage bags flat. It is so much easier to store many, many breast milk bags if they have first been laid flat. Once frozen, they can be gathered into larger containers for storage.
Don’t forget to write the date and the amount (if not indicated on the container), on each storage container.
Don’t toss it out! Most experts recommend not throwing out any frozen breast milk before the maximum date of expiration, unless it just smells foul.
Freezing breast milk in small portions, between 1-3 oz each, is a great way to not waste breast milk. Cubed storage trays with lids, like this one from Fresh Baby, make it easy to freeze. Once frozen, pop them out into a larger storage bag or container! (These make great teething options once Baby has teeth coming in!)
You’ll want to be sure to use BPA free storage bags. Lansinoh’s are easy to use and include measurements right on the bag so you can see how much is in each.
Storage trays can be useful. Once you’ve got a good stash going, you may find that a tray like the one from The First Years is helpful to ensure you use the oldest milk first.
Thawing Breast Milk
What if your breast milk smells when you thaw it out? Unless it smells sour, rancid, foul, it is most likely fine. A slight soapy smell just means there’s more lipase activity going on (fats are breaking down in the milk).
What if your baby won’t drink it? If your baby won’t drink it, it’s possible that your milk has excess lipase. If this is the case, one of our authors, Rebekah, has written out a wonderful solution for how to scald breast milk with excess lipase.
What if you find some breast milk in the back corner of the freezer, past the expiration date? Don’t throw it away!! There are a number of ways to use your expired breast milk! Eye and ear infections generally clear up very quickly with just a few drops throughout the day for several days. You can use it on sore or cracked nipples. Make soap. Feed your plants. Just don’t toss that breast milk—you worked too hard for it!
Finally, if you need some tips for pumping, be sure to read our 20 tips for pumping breast milk!