Parenting Tips


August 1, 2019

Breast Milk Storage: Do's & Don'ts

If you’ve been breastfeeding and are heading back to work or want to have bottles on hand for well-deserved days and evenings out, pumping enables you to conveniently stock up on breast milk. But, when it comes to storing breast milk, there are so many things to consider that the thought of it can be downright confusing and overwhelming.

There are definitely do’s and don’ts when it comes to breast milk storage, which we’ll cover below. Read on to find out how long breast milk can sit out, what types of storage containers to use and more – and become confident in your breast milk storage know-how!

  • Storage on the Counter: Store in the coolest area on the counter and out of direct sunlight. Don’t store breast milk for any amount of time at temperatures above 77º F due to the risk of bacteria growth.
  • Storage in a Cooler Bag: Breast milk can be safely stored in a cooler for up to 24 hours with ice packs on the milk container at all times. Only open the cooler if you need to. 
  • Storage in the Refrigerator: Place breast milk in the center of the refrigerator and as far back as possible. Never store it in the refrigerator door, as temperatures can vary widely in this area.
  • Storage in the Freezer: Store in sealed containers or breast milk storage bags in the back of the freezer where temperatures are the most consistent. Be sure to label containers so you can see which milk is the oldest, since you’ll need to use that up first. 

When you’re ready to use stored breast milk, use a convenient bottle warmer to safely bring it to just the right temperature for feeding.

What Containers are Best for Storing Breast Milk?

The top recommendation for storing breast milk is in a clean, capped glass or hard plastic, BPA-free container. You can also use special plastic bags designed for milk collection and storage; however, these bags can tear or leak. To avoid losing breast milk in the event a bag becomes damaged, place the bags in a hard plastic food storage container with a tightly sealed lid for added protection.

Note that breast milk expands as it freezes, so don’t fill containers all the way.

How Long is Breast Milk Good For?

This answer depends on the specific storage method. The general guidelines by storage method are as follows:

  • Room Temperature: Fresh breast milk can be kept at room temperature for up to six hours, although it’s optimal to use or store properly within four hours, especially if the room is warm.
  • Insulated Cooler: Fresh breast milk can be stored in an insulated cooler with ice packs for up to one day.
  • Refrigerator: Fresh breast milk can be stored in the back of the refrigerator for up to five days, although it’s optimal to use it or move to freezer storage within three days. 
  • Deep Freezer: Fresh breast milk can be stored in the back of a deep freezer for up to 12 months, although it’s optimal to use the frozen milk within six months.

Can Fresh Breast Milk be Combined with Stored Breast Milk?

Freshly pumped breast milk can be added to refrigerated or frozen milk that was pumped earlier in the same day. However, you’ll need to thoroughly cool the freshly pumped breast milk in the refrigerator or in a cooler with ice packs before adding it to previously chilled or frozen milk. Never add warm breast milk to frozen breast milk since it will cause the frozen milk to partially thaw.

Follow these basic breast milk storage guidelines and discuss any specific concerns or questions you have with your pediatrician and you’ll have peace of mind knowing your baby will be well fed when you’re at work or enjoying some time for yourself.

Be sure to check out our Latch™ bottles, designed with a unique accordion nipple to ease the transition from breast to bottle and back. These are the perfect bottles to use when you’re beginning to transition from solely breastfeeding to feeding your baby stored breast milk.

BONUS: Enjoy 15% off all Milkmakers products now through August 7 with promo code MM15!