Did you know you can actually leave your breastmilk out on the counter all day (up to 8 hours!) without having to throw it out?! Amazing!  Breastmilk has incredible anti-bacterial, anti-infective and anti-microbial properties to it which allow for long term storage, even when it is not in a fridge.  A study done by Pardou et al. (1994) actually found that some of the breastmilk from the study that had been left in the fridge for 8 days, had a lower bacterial count in it than when it was first expressed! It is not a bio-hazard, and stores really well! You can leave your breastmilk for up to 8 hours on the counter, up to 8 days in the fridge and for months in the freezer.

Storing breastmilk is something that almost all of us breastfeeding mothers will need to think about at some point or another.  Even though all three of my breastfed children have never had a bottle, I have had to hand express at some point or another during the years, as they got older and I was separated from them for long enough to have to express for comfort.  In these cases I kept the milk in the fridge for a few days to one week, or I popped it in the freezer.  I would then mix it with their food, use it for medicinal purposes (CLICK HERE for more info. on this!) or I donated it. Do not throw it out!!!!

Here is a poster that I created of the guidelines on safely storing milk for a healthy, full term baby.   It is also important that you have cleaned the containers in hot soapy water and that they are well rinsed.  

breastmilk storage guidelines

Some commonly asked questions about breastmilk storage:

1. My baby only drank half of the milk I gave her, can I re-use the left over milk?

There are no studies on this, but it is generally accepted that the left over milk may be used within a couple of hours.  Some mothers will go longer than this but because there is no research, it is up to each individual person to do what they are comfortable with.  Is your baby healthy? Have you collected the milk in a very clean, safe way? Is your milk fresh or frozen?  If your baby is healthy, you have collected the milk in a very clean way and your milk was expressed recently or was refrigerated then it is more likely to be safe to re-use after a longer period of time.  Breastmilk has the most anti-infective properties when it has been freshly expressed, followed by refrigerated and frozen milk.

2. How should I heat up the milk?

Milk from the fridge can be heated slowly in a hot bowl of water (not boiling).  Milk that has been frozen can be defrosted in the fridge or under cool running water which is then slowly heated to room temperature.  Milk that has been defrosted in the fridge can be stored for up to 24 hours.

3. How much milk should I store in the same container?

If you can store smaller amount of milk within each container, then you will be less likely to waste left over milk.  60-120mls (2-4 oz) is a good amount as this is what your baby is likely to eat in a single feed.

4. Can I put milk that has been expressed later that day or on a different day in the same container?

You can add milk from a different day or time but it is important to put a date on the container from the day of the FIRST bit of milk that you expressed so you know when you need to use it by, refrigerate it or freeze it.  

5. What should I store the milk in?

Glass is best as there is then no need to worry about what type of plastic you are using.  At the very least, choose a container that does not contain BPA. There are now plastic storage bags made especially for expressed breastmilk which most baby stores now carry. Make sure the plastic or glass container has been washed in hot soapy water and rinsed, or has been washed in the dishwasher. It is also important to leave an empty space at the top of the container so the milk has room to expand if frozen.

6. My breastmilk smells like soap and seems to be “off”!! Do I need to throw it out?

NO! This happens because some women have a higher level of lipaze which is an enzyme that helps to break down the fats in breastmilk.  It is because of this that breastmilk will sometimes seem “smelly” or a bit “off”.  Some babies are not bother by this at all, yet others will refuse to drink it.  You can fix this by scalding the milk.  To do this you just need to heat the milk right after it has been expressed until you start to see bubbles around the edge (just before it gets to a boil) then quickly cool and freeze the milk. 

7. What about preterm babies?

It is important to take some extra precautions when you are storing milk for a preterm baby.  

-Room temperature up to 4 hours.

-In the fridge for 24-48 hours.

-Freezer (in a separate door) 3 months and deep freezer 6 months. A freezer compartment within a fridge is not recommended.

-Insulated cooler 24 hours.



Breastmilk can be used for many medicinal purposes topically.  Eczema, eye infections, ear infections, acne, sore nipples, diaper rash, cradle cap and sunburns are a few of the many ailments you can use your expired milk for. Some women store their milk in a syringe (without a needle attached to the end of course)! This way they can thaw a small amount when needed to use topically. Do you have extra breastmilk which has not expired yet but you know you will not use it? Donate it! Find your local Human Milk 4 Human Babies chapter.

I have compiled information from La Leche League International and Kellymom for this article.

Are you currently working or returning to work and have questions about pumping, milk supply and/or bottle feeding? Check out my BOOBinar (breastfeeding webinar) on this topic!