Do Breast Milk Storage Bags Expire

Do Breast Milk Storage Bags Expire?

Breastfeeding sessions can be overwhelming, especially to new moms who have not got the nook on the proper baby attachment and positioning. But the good thing is that everything seems easy once you get used to it. Some mothers opt not to breastfeed and instead express breastmilk and bottle feed their children.

Expressing breastmilk requires optimum and hygienic storage conditions so that the milk maintains its freshness and safety for the baby’s use. The most recommended storage unit is the milk storage bag. These bags are so versatile and freezer safe. They are also affordable, especially when bought in large amounts.

But what happens when you buy a stock full of milk storage bags? How long can you keep them? Will they expire? Stay locked!


Do Breast Milk Storage Bags Expire?

Unopened breastmilk storage bags don’t expire and will keep indefinitely for as long as they are stored in a cool and dry place, away from moisture and oxygen. The best place to store milk storage bags is in an airtight container in a closed cupboard. The airtight container prevents the entry of moisture and bacteria, reducing the risk of contamination with mold or bacteria.

Most milk storage bags are pre-sterilized to make them safe for use. This means you can use them straight from their package without washing. These bags are also for one-time use and should be discarded once you are done with them. So, remember to dispose of your milk storage bags anytime you’re through using them.

How Can You Safely Store Milk Storage Bags

Here’s the best way to store milk storage bags to ensure they last long.

Unused Bags

These steps will help you store your milk storage bags effectively to avoid contamination:

  • Start by opening the package of the milk storage bags.
  • Remove the storage bags from their original packaging and place them in an airtight container. This is to avoid them getting moist or contaminated by bacteria.
  • Store the unused milk storage bags in the container for as long as they last and use only as needed.

For Bags In Use

The bags you use to store breastmilk should be well-taken care of to avoid contamination and keep the milk inside safe. Follow these steps for safe milk storage:

  • The milk storage bag is pre-sterilized before packaging, so use them immediately.
  • Avoid storing breastmilk storage bags in the kitchen fridge with other food products. Doing so can make the milk storage bags pick up odors from the foods stored in the fridge. Instead, use a mini-fridge that you can place in the nursery.
  • When freezing the milk storage bags, place them on the bottom side of the freezer, away from the door. Storing the bags near the freezer door means they’ll be affected by frequent temperature changes when the door is opened. Freezer doors are also warmer than other parts of the freezer.
  • Organize your storage bags by date and volume, making it easy to locate the right bag. Start by labeling the milk storage bags with the date you expressed, the best-by date, and the volume they contain. Then organize the bags in the freezer, starting with the latest ones and finishing with the old ones.
  • Stand the storage bags and place them side by side. This way, they occupy less space.
  • Breastmilk bags can be stored for up to 4 days in the refrigerator and six months in the freezer. Take caution that the milk bags don’t break or tear during storage.

What To Do With Extra Milk Storage Bags

Sometimes, when you are done with nursing, you may end up with lots of milk storage bags and wonder what to do with them. Discard the storage bags that are already used. You can also take them to the manufacturer’s stores for recycling if they do.

On the other hand, if the milk storage bags are unused, there are many things you can do with them. You can use them to freeze anything liquid as they are food-grade and thus safe for all foods. For instance, you can use them when freezing soups, stock, or pureed baby food. You can also use them to make ice packs for lunches.

How Long Can You Store Breastmilk?

How long breastmilk can last depends on the storage temperatures. According to the Center for Diseases Control And Prevention, this is how breastmilk can last:

  • Six to eight hours at room temperatures 25 degrees Celcius or below.
  • Seventy-two hours when refrigerated in the rear side of the fridge at temperatures forty degrees Celcius or lower.
  • Two weeks when stored in the refrigerator’s freezer compartment at -150 degrees or lower.
  • Three months when froze in a separate freezer compartment at temperatures -180 degrees or lower.
  • Up to 12 months when frozen in a deep freezer at temperatures -20 degrees or lower.

How To Thaw Frozen Breastmilk

Knowing the right way to defrost frozen milk is crucial in ensuring the milk retains its nutritional composition and flavor. There are a couple of ways of thawing breastmilk:

In the refrigerator – this is the most recommended method of thawing breastmilk. To thaw milk in the fridge, place your frozen in the fridge a day before you plan to use it. Let the milk stay in the refrigerator overnight or for 24 hours. Once the time lapses, remove the thawed milk and warm it in a bottle warmer or a hot water container before feeding your baby. Defrosted breastmilk should not be frozen again.

In a hot water container – defrosting breastmilk in a hot container is also a great way of thawing milk. However, it may take longer depending on the milk quantity. Thawing milk in a hot water container gives you the advantage of warming the milk simultaneously. So, you don’t have to warm it again, unlike defrosting in the fridge. If the water gets a shade too cool, remove it and add hot until the milk thaws fully.



To sum it up, do breastmilk storage bags expire? No, unused breastmilk storage bags don’t expire and can last indefinitely. However, once used, they should be discarded thereafter.