Once you’ve pumped your milk, what do you do with it? You can:
- Feed it to your baby at the next feeding
- Store it in the refrigerator
- Freeze it
Below are summaries and best practices regarding each of these options.
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Feeding your baby fresh milk
This is probably the easiest option if it’s feasible for you.
Obviously, it isn’t feasible if you’re not with your baby, like if you’re at work. Also, some moms can become stressed about pumping enough milk to cover the next feeding and prefer to be a feeding or two ahead of their baby. However, if it works for you, it eliminates the need to warm bottles or deal with freezer bags, which is nice.
If you use freshly pumped milk, it can safely stand at room temperature for 4-8 hours. Once you’ve finished pumping, you can set it aside and then give it to your baby when he or she is hungry.
My experience: This was my preferred option when I wasn’t at work and once my supply was stable enough. Also, when I had dropped the middle of the night pump, I took the last pumped milk of the evening upstairs with me to bed and then was able to feed it to my baby in the middle of the night without needing to warm it.
Reusing expressed breast milk
If your baby doesn’t finish a bottle of freshly pumped or refrigerated milk, you can offer it to the baby again within two hours. Some mothers choose to leave the milk at room temperature and others prefer to refrigerate and rewarm. Either is fine.
Using refrigerated milk
Freshly pumped milk will be fine in the refrigerator for 3-8 days. If you have a number of bottles in the refrigerator at any given time, it is a good idea to label them with the pump date (you can use a piece of masking tape) or order them with the oldest bottles in front so that they are used first.
If you have a lot of bottles in your fridge and it’s taking up too much space, many moms in our Facebook group use the “Pitcher Method,” where they combine all the milk they pump in a day into a large container. At the end of the day, they prep bottles for the next day and freeze any extra milk.
If you are exclusively pumping, it is worth seeing if your baby will take cold bottles, as it eliminates the warming step and makes things much easier when you are out of the house. Some babies don’t mind them (or will get used to them if you gradually make them colder) and others will only take warm bottles.
If you do need to warm the milk, there are a few different ways to do it. You can run it under warm water in the sink, put it in a container of warm water, or you can use a bottle warmer. Never microwave breast milk or formula, as the microwave can create “hot spots” that will burn the baby’s mouth, and make sure to check the temperature after warming by squirting a bit on your wrist or hand.
Over time, cream will rise to the top of the milk as it is stored in the fridge. This is normal and nothing to worry about. If you warm the milk, I find that the warming process does a decent job of mixing it together. If you don’t warm it, swirl it gently to mix. (The recommendation used to be not to shake breast milk, but it’s unlikely this has much of an effect.)
Freezing breast milk
Breast milk can be frozen in glass or plastic bottles or breast milk storage bags (these are my favorite, and I’ve had the fewest problems with holes during the defrosting process versus other brands).
Many sources recommend storing milk in 1-4 oz portions. Personally, I have found it easiest to store it in whatever my baby’s current feeding amount was at the time, because it was most likely that that would be the amount that I would need. If I did happen to need less than a full feeding and didn’t want to waste the milk, I defrosted the bag, poured what I needed into a bottle, and put the rest in the fridge for later (usually still in the breast milk bag).
It’s a good idea to give your frozen breast milk a test run with your baby before building a large freezer stash, in case you have a lipase issue.
When freezing the milk, label it with:
- The date the milk was pumped (if you have milk from more than one pumping session in the same bag, use the earlier date).
- The amount of milk in the container.
- Your child’s name (if your child will be using the frozen milk in a childcare setting).
How long frozen milk is good for depends on the freezer:
- In a freezer compartment of a mini-fridge: about 2 weeks
- In a standard freezer: 6 months
- In a deep freezer: 6-12 months
To maximize the length of time that milk will last in your freezer, consider regularly rotating your freezer stash.
(Wondering when it makes sense to start freezing milk? Here are my thoughts on this.)
Using frozen breast milk
There are two approaches to thawing milk. The first is to put in in the refrigerator to the thaw slowly, which will take about 12 hours. The other is to put the container of frozen breast milk in water. Whether you should use warm or cold water depends on when you’ll be using the milk.
If you plan to use the entire bag of breast milk for the next feeding, it’s easiest to put the bag under warm running water or in a container of warm water. This will thaw and warm the milk at the same time, and it’s usually ready to go within 5-10 minutes, depending on how warm the water that you’re using is.
However, if you plan to use only part of the milk – or if you’re defrosting for a later feeding (for example, if you’re prepping bottles for the next day’s childcare) – you’ll want to use cold water. Then, once the milk is defrosted, you can put it into the bottle that will be used for feeding and back in the fridge.
If you have had problems with leaks/holes in your breast milk bags during the defrosting process, you can try putting a zip-top plastic bag around the one that you’re defrosting before you put it in water. If you’re defrosting in the fridge, put the bag in a bowl to catch any leaks. (More tips on this here.)
Milk should not be thawed at room temperature.
Frozen milk should not be refrozen. Once it has been thawed, it should be used within 24 hours.
If you need to travel with fresh or frozen breast milk, here are some tips for packing your breast milk.
References
- CDC. “Proper Storage and Preparation of Breast Milk.” https://www.cdc.gov/breastfeeding/recommendations/handling_breastmilk.htm
- Bonyata, Kelly, IBCLC. “Human Milk Storage.” https://www.kellymom.com/store/freehandouts/milkstorage01.pdf
- Bonyata, Kelly, IBCLC. “Reusing Expressed Breastmilk.” https://kellymom.com/bf/pumpingmoms/milkstorage/reusing-expressedmilk/
Hi! I have a quick scenario question about using frozen breastmilk. I have been exclusively pumping since the end of January, but have yet to use my stash (I realize I should have tested it before now – whoops!) Right now, I take my freshly pumped breastmilk out of the fridge a couple hours before my baby eats so it has a chance to warm up slightly. Can I do the same thing with frozen breastmilk? For example, can I first thaw frozen breastmilk in the fridge (I know it takes about 12 hours), and then let it sit at room temperature for a couple hours to warm a bit? Or is this a no no?
Thank you!
Jaclyn
Hi Jaclyn! I have searched everywhere for this question and can’t find an evidence-based answer. I would probably default to leaving it in the fridge and warming it as a result. Sorry!
Hi Amanda – For some reason I was not able to reply to your comment so I am replying to my own comment. Thank you for looking into it! I could not find any information either.
Hi there,
I see many have asked the question about being able to still use a bottle that was refrigerated, warmed but never drank from. I see you have stated the CDC day it must be consumed with in 2 hours. Do you happen to know why it can’t be re-refrigerated and heated up again? I under stand when it’s been drank from with possibility of bacteria but if it never touched the baby’s mouth what’s wrong with it?
Thanks for any input
Hi Caren! It’s because the warming process allows bacteria to grow more quickly. I don’t know why 2 hours is the guideline they chose but that is the logic behind it. Hope that helps!
Hi Amanda, May I know if it’s alright to leave freshly pumped milk at room temperature for around 3 hours before refrigerating it?
My understanding is that that’s okay. 🙂 I would refrigerate it as soon as you can though.
Hello!
my milk supply has increased a lot, my lo is one weeks old & takes 2oz every feeding.
i usually pump 5 to 6 ounces i store it in the fridge and only take the 2oz out & put the rest back, wondering of thats safe?
Hi America! Are you taking the 2oz out, putting it in a different bottle, and feeding it? If so, that’s fine! If you’re feeding in that bottle and putting it back, the rest of the bottle should be used within 2 hours.
Hi Amanda,
Is there a must to store frozen milk in a separate deep freezer that is used for storing milk and milk only?
Any documented cases of cross-contaminated with other food that you have come across?
Many many thanks!
Linh
Hi Linh! Not that I know of!
uestion: I will put milk from fridge in bottle, warm it up. I always fill bottle to 6 oz, he will take 4 usually (up to 6 at times so I always fill to 6) so I usually have 2 oz leftover. Put 2 oz in bottle back in fridge, and then add 4 more oz cold milk and reheat. Is this ok? How often can I reheat that same bottle? I’ve heard twice. So for example if I’ve reheated that bottle twice but there is still milk leftover at the end, do I have to get rid of it? What are the current recommendations? Thank you!
Hi! I would just put 4oz in the bottle instead and warm more up if he ends up taking more. I wouldn’t keep doing it as you’ve described – there is the chance for bacteria to grow in the leftover milk. I hope that helps!
Hi Amanda! Thanks so much for all of the helpful information 🙂 I was wondering if you know- I have used all of the available space in our inside freezer and garage freezer so I bought a deep freezer today to transfer all of the milk into that. Do you know if it will then be good for up to a year or still only the 6 months?? Thanks so much!
Hi! It depends on how long it was in the other freezers and how often you opened the doors of the other freezers. If you had it in there for a few weeks and rarely opened the doors, probably closer to a year. If it was longer and you opened the doors frequently, you might want to keep it for a shorter amount of time.
Hi Amanda, i’m mother of a 10 week girl and started exclusive pumping a week ago. I’m so glad that i found your page, so much useful information for a new pumper like me. Thank you so much.
I prefer to feed my baby with freshly pumped milk and put any extra in the fridge. By the end of the day, i collect all the extra and put into the freezer. My question is what is the expiry date of the frozen milk now? Is it a full 3 months or should it be 2 months only as a third of its shelf-life has already passed in the fridge (given the shelf-life in fridge is 3 days).
Thank you again for your hardwork!
Hi Ha Bui! It should be fine for the full time, I’ve never seen any experts suggest discounting the time based on fridge time! 🙂
Hi Amanda, I warmed up a bottle of fresh breast milk that wasn’t refrigerated but my baby didn’t want to drink it. The milk never touched his mouth. How long is it safe to keep this milk? Can I freeze it?
Thanks!
It’s only good for 2 hours according to the CDC unfortunately!
Hi! Can I re-refrigerate milk that was in the refrigerator and warmed but not consumed?
Hi Misty! You can but the CDC guidelines state it should be used within 2 hours of being warmed. (So you can re-refrigerate and re-warm, but only within 2 hours. You can also leave it at room temp.)
I took a refrigerated bottle and warmed it for my baby. She didn’t drink it all. Must she drink the rest within 2 hours before discarding?
That’s what the CDC recommends. 🙂
Hi Amanda,
if I take out the milk from refrigerator, under room temperature, how soon my baby has to consume it please?
Thanks again!
Hi Rena! About 4 hours.
My little guy is having trouble gaining weight, so they’re having me pump after nursing and offer him the pumped milk. My question is can I still save and freeze what he doesn’t take? Or do I have to discard it since it touched his mouth?
If it’s in a bottle he drank from, you have to discard it. You could try offering smaller bottles, and then freeze any milk you don’t offer?
Can you take milk out of the refrigerator and set it on the counter to “warm up” before your next feeding? IE: middle of the night feedings to take a bottle out after a feeding to be used at the next one in 3-4 hours? I have not been, but curious if there’s guidelines on if you can safely do this. My LO seems to spit up cold milk.
You can. I answered this with more detail here! 👍
https://exclusivepumping.com/can-i-feed-my-baby-this-breast-milk/
Hi Amanda, can I transfer the milk to freezer after set in the refrigerator for 2 days? Thanks!
Yes you can! 🙂
Hello,
Thank you for providing all this info with pumping. It’s a great resource. I have a question about frozen breast milk. I need to transfer my frozen breast milk from my in-laws deep freezer to my refrigerator freezer to be used within a few days. Is it safe to do so? I have found lots of info from freezer to deep freezer but not vice versa.
Thanks,
Marina
As long as you’re using it within a few days it’s fine. 🙂