Everything You Should Know about Breastmilk Storage

Everything You Should Know about Breastmilk Storage

  • By Emily Goldstein

Reviewed by: Michael W. Woolridge B.Sc., DPhil

Are you using breast milk to feed your baby? If so, it’s important to make sure that you’re storing it properly. This helps ensure that your baby doesn’t get ill and stays healthy along the way. When it comes to storing your breast milk properly, there are some general rules of thumb to follow. However, it is crucial to remember that different factors such as milk volume, room temperature, cleanliness, and more play a part.

Storing milk safely enables you to have milk on hand whenever your baby needs it.

Before handling your milk

You’ll want to make sure your hands are clean with soap and hot water, but certain hand sanitizers can also be a substitute. If you’re using a pump make sure it is clean as well as the area around you. If you notice anything which is generally unclean or dirty, then either clean or replace it.

Where & how to store your breast milk?

After you’ve expressed your milk, it’s time to store it. Immediately after your breast milk is expressed, place it in the fridge to cool. You then have time to decide whether to freeze it for future use, or simply to use it at your next feed. It is important to note that improper storage can cause harm towards your baby so it is an important subject to be knowledgeable on.

What should you store your breast milk in?

Figuring out the best way to store your breast milk is an important decision. This can differ depending on what type of storage you prefer to use. The CDC recommends using exclusively bags or bottles designed for storing breast milk to avoid contaminants like BPA. Disposable plastic bags or plastic bottle liners can be used for storing breast milk, but they should not be used exclusively when warming breast milk as the bags can puncture.Because of this if you’re using a disposable bag you should put it in a separate container when warming. The best options are sealable breast milk storage bags or glass containers with tight-fitting lids, although if you don’t have glass containers plastic containers as long as they’re food safe are okay as well.

How long does expressed milk stay fresh?

  • Room temperature – Milk can be stored at room temperature for up to six hours. Although this isn’t the best, if you have the option to chilling within 20-30 minutes of expression it is still best practice. If you don’t have access to a fridge a chilling bag with a freezer pack inside is a good alternative. As previously mentioned, if the room is warmer either when expressing or storing it has the potential to make the milk unusable more quickly. Because of this, it’s ideal to either store your milk in a cold area or use your milk within four hours.

  • Insulated cooler – If you’re using an insulated cooler with ice packs your breast milk can be used for up to one day.

  • Refrigerator – In clean conditions milk can be kept in the refrigerator for up to four days. However, if you aren’t sure you’re going to use the milk after three days then it’s best to put it in the freezer, although depending on the conditions it is best to switch to the freeze before three days to guarantee freshness.

  • Freezer – If your milk is in the freezer it will be good for 6 months but up to twelve months is acceptable as well. Although you can freeze items indefinitely, 6-12 months is recommended to make sure the nutrients are kept.

What to know about frozen breast milk

If you’re freezing milk it’s best to store it in smaller quantities to make sure you don’t end up wasting anything. Ideally it would be in portions of one feeding at a time. If you’re trying to find out which container would be best to store your milk make sure there’s at least an inch of space at the top since milk expands when it freezes.

How to thaw frozen breast milk?

There are a few ways you can go about thawing frozen breast milk. If you’ve freshly taken the container out of the freezer, run it under lukewarm water. You can also place the container in the fridge overnight or in a bowl of warm water. After you’ve thawed the frozen milk, stir it around to make sure if the fatty part of the milk has separated and is reincorporated.

Do not rush thawing your milk by putting it in the microwave as this can deplete valuable nutrients within the milk. Microwaving your wilk can also result in a super-heated core which can pose a serious risk or heat shock and burn the baby’s mouth. Once you have your breast milk thawed, use it within two hours and never refreeze it.

Frequently asked questions about breast milk storage

Can breast milk storage bags be reused?

A major benefit of breast milk storage bags is that they can easily be cleaned and reused unless they’ve fractured or disintegrated during freezing or thawing in which they should be thrown away. You just have to make sure you’re thoroughly cleaning the bags and that the bags aren’t leaking.

How to put breast milk in storage bags?

This can be a daunting task, but we have some helpful tips. All you have to do is simply transfer your expressed milk to the bag, seal the bag, and write the date and time on the bag before storing it in the refrigerator or freezer. Then when you’re ready to re-use your milk, thaw it in date order especially if the baby was born preterm as preterm milk may have raised nutrient level adapted to their premature birth.

In summary

Breast milk storage is an important step of feeding and expressing milk. It isn’t an area to be ignored or forgotten about as it can have such a profound effect on your baby's development. It’s important to remember that storing your breast milk incorrectly can potentially cause nutritional deficiency or sickness for your little one.


Breast milk storage: What to use & how long to store Breast Milk. Retrieved August 10, 2022 from https://my.clevelandclinic.org/health/articles/12255-breast-milk-storing

Tips for storing breast milk. Retrieved August 10, 2022 from https://www.mayoclinic.org/healthy-lifestyle/infant-and-toddler-health/in-depth/breast-milk-storage/art-20046350


The information contained in this article is for educational and informational purposes only, and does not substitute for professional medical or health advice. Always consult a medical professional or healthcare provided for any medical advice, diagnoses, treatment, or health objectives.