Storing Breastmilkbags of frozen breastmilk

There may be times when you need to pump and store your breastmilk for later use whether it's for school, work or an evening out. It easiest to store your milk in the amount your baby will drink. If you aren't sure, you can do a few 2 ounces and a few 1 ounces that way there is nothing going to waste.

Breastmilk can be stored:

  • At room temperature for up to 4 hours.
  • In the refrigerator for 3 days. No need to freeze if you will be using your milk during this time. Put the date on the bottle or milk storage bag. Your milk is best if not placed in the refrigerator door. Your milk will separate. The fat will be at the top of the bottle/bag. This is normal. It’s ok to feed your baby this. Before feeding your baby you just need to gently stir or swirl your milk so the fat mixes back in.
  • In the freezer –6 months. Wow! You would never freeze formula! If you need to freeze your breastmilk you can use storage bags or glass bottles. Leave space at the top, about 1 inch, as the milk will expand once frozen. You can date and write the number of ounces on the container. Store your milk near the back of the freezer, never in the door.

Whether refrigerated or frozen always use the oldest milk first.

Safe Storage

Fresh Breast MilkThawed Breast MilkTemperature
Countertop 3-4 hours
1-2 hours Room temperature must not be higher than 85°F or 29°C. Containers should be covered and kept as cool as possible.
Insulated cooler bag
24 hours For transport only Keep ice packs in contact with milk containers and limit opening the cooler bag.
3 days
24 hours At or below 39°F or 4°C
Freezer section inside of a refrigerator
2 weeks
Do not refreeze
At or below 5°F or minus 15°C
Freezer with separate door or deep freezer
6 months
24 hours Below 0°F or minus 18°C


Breastmilk can be warmed in a bowl of warm water or under warm running water. Never heat in boiling water or in the microwave.

When defrosting your breastmilk you can place in the refrigerator for up to 24 hours or you can follow the same guidelines for warming as mentioned above. Breastmilk defrosts pretty quickly. Once you have defrosted your breastmilk it needs to be used within 24 hours. Never refreeze defrosted breastmilk.

The color of your milk may change and look different from one day to the next. It depends on the age of your baby and the time of day you pump; these are two ever-changing things! If you think your milk looks bad or smells funny please call us first before throwing it out. No one I know cries over spilled milk unless it’s breastmilk!