If you are an exclusive pumper that has enough supply to pump extra milk, it’s a good idea to start freezing your milk in breast milk bags and building up some breast milk freezer storage.
A freezer stash can be great for peace of mind: it makes it easier not to cry over spilled breast milk, it’s there if you experience a drop in supply, and it helps you not throttle your partner when they accidentally leave the daycare bottles out overnight on the counter. (Not that that has happened to me.)
Breast milk doesn’t last in the freezer indefinitely, though. Here is how to help make sure you don’t waste any milk by rotating your freezer stash.
This post may contain affiliate links, which means that if you click through and make a purchase, I’ll be compensated at no additional cost to you. I only recommend products I love! More info here.
How long can breast milk be kept in the freezer?
The length of time that frozen breast milk will be good in the freezer depends on the type of freezer that you are using (more information is available here):
- In a freezer compartment (like in a mini-fridge): 2 weeks
- In any other type of freezer: Up to 6 months is ideal, up to 12 months is acceptable
(Note: The CDC recently stopped distinguishing between regular freezers and deep freezers, so these guidelines are now more straightforward.)
Therefore, depending on how long you want to feed your baby breast milk, the earliest milk that you freeze may not last as long as you need it to.
This is where rotating your freezer stash come in. Rotating your freezer stash means using the oldest milk that you have on hand to feed your baby, while the newer milk that you pump goes into the freezer to replace it.
Rotating frozen breastmilk: How should I use my freezer stash of breast milk?
There are a couple of different approaches that you can take to rotating your freezer stash.
Here are the two that I used:
1. Pick one day each week where you baby only eats frozen milk
On this day, you’d feed your baby your oldest frozen milk. Then, all of the milk that you pump that day (that you would have fed to your baby) goes into the freezer.
So, for example, let’s say every Monday is frozen milk day. You’d freeze everything that you pump that day (you can do it all at once at the end of the day or on Tuesday mornings), while feeding baby the oldest milk that you have frozen.
You can prep all of the bottles on Sunday night by thawing in cold water, or defrost the milk as you need it – whatever works best for you.
2. Every day, give your baby one frozen milk bottle
To do this, you’d designate one bottle per day as the “frozen” bottle. This could be at any time of the day, it doesn’t matter when (and it could be different times on different days, or always the same routine).
Then, you’d freeze the milk that you would have fed your baby at that feeding.
One advantage of this method is that your baby still gets fresh milk, with all of its antibodies, every day. The main disadvantage is that you have to deal with defrosting and freezing milk every day. Fresh milk is easier to manage.
When should I start using my frozen breast milk?
You should start using your frozen breast milk within a couple weeks of starting a freezer stash.
Some people have a lipase issue where their milk starts to taste bad after some time passes. For these people, fresh milk and even milk that’s been refrigerated for some time may taste fine to their baby, but milk that has been frozen tastes soapy. Some babies will refuse this milk due to the taste.
There is a way around this – you can scald your breast milk after you pump it – but once the milk is off, it’s off, and scalding won’t work.
Because you don’t want to build up a huge freezer stash of milk your baby won’t drink, it’s a good idea to start using it right away to test for this issue, even if it’s just a few bottles a week to rotate out old milk.
Is there anything I can do to make dealing with my breast milk freezer storage easier?
Freeze your breast milk flat (like bricks) in your breast milk bags – they take up less room this way.
In order to know what milk is the oldest, you’ll want to make sure that you label the breast milk bag with the date (if you’ve combined milk from more than one day in the bag, use the earlier date).
Then, organize your bags so you don’t have to spend a lot of time digging to find the oldest ones. Some people put their bags into zip-top plastic bags and then put a large label on the bag with the dates, so they are easy to find:
If you’d like to store frozen breast milk and then wean when you have enough to make it to your goal, here are some tips and things to consider.
If you’re not sure whether or not your milk is still good, you can test it with MilkStrips. (More on these here.)
Finally, as you rotate your milk, if you find that you have too big of a freezer stash (i.e., no room for grown-up food), you can consider donating your breast milk to a milk bank.
Do you rotate your milk? Tell us how you do it in the comments!
References- Bonyata, Kelly. “Human Milk Storage – Quick Reference Card.” https://kellymom.com/store/freehandouts/milkstorage01.pdf
- CDC. “Proper Storage and Preparation of Breast Milk.” https://www.cdc.gov/breastfeeding/recommendations/handling_breastmilk.htm
“In the freezer for about 6 months is best; up to 12 months is acceptable. Although freezing keeps food safe almost indefinitely, recommended storage times are important to follow for best quality.”
https://www.cdc.gov/breastfeeding/recommendations/handling_breastmilk.htm
In ABM Clinical Protocol #8, the Academy of Breastfeeding Medicine Protocol Committee writes: “The basic principles of freezing dictate that frozen foods at -18C (0F) are indefinitely safe from bacterial contamination, although enzymatic processes inherent in food could persist, with possible changes in milk quality.”
One the many best tips i learnt from you. Now i send these to my friend!
I’ve read that milk pumped in the evening has more melatonin. Should I try to label the bags AM/PM and then try to give PM bags when it’s getting later in the day? Or is that more trouble than it’s worth?
Hi Carrie! I think it’s more trouble than it’s worth. Here’s more thoughts:
https://exclusivepumping.com/day-milk-night-milk/
I’m glad I found this article, because I was beginning to worry about my supply I have about 148 oz stores so far, I use the app Baby Log to keep track of feeds pumping sleep and diapers. I have used my stash occasionally when I couldn’t pump at the time and started it about 2 weeks after he was born. Right now my latest date I have is march 23,2021. I’m hoping to just do one bag a day frozen to keep all the milk as fresh as possible each bag has between 5-6 oz which for him is two- three bottles a day. Will this work to bring my stash more current? Of course for the bag I remove I will be replacing with a fresh batch, I pump 3-4 times a day I am an over producer, so I tend to wait 6-8 hours between pumps to try and level out how much I’m producing. Normally I would pump 10-15 oz in one session with on day I pumped 17oz for two sessions making 34oz so I didn’t pump again till the next day. I want to feed him until he is at least one and if he wants to continue I don’t mind, my concern is if I am producing too much milk. I will only freeze if I don’t think he will eat it within 8 hours because if I don’t then I start getting a big stash in the fridge. I feel a bit lost but will definitely start rotation to keep everything as fresh as possible and check to see if it taste soapy. My baby eats about 15-20 oz a day and the app told me that the if I stopped pumping today that is only enough milk for 8-10 days, I only recently started producing 30-40 oz a day, it’s been about a week. I figured that was normal? And my body preparing for his growth spurt and when he will need 3-4 oz a feed instead. He is a few days away from being two months old.
Hi Sierra! Congrats on your baby. That does sound normal. Can I ask how old your baby is and what your pumping schedule is like?
I barely started to freeze (regular freeze) my BM in order to have it for months vs. just a few days. I had it in the fridge first. My oldest BM is from 9/8/2020 and had been in the fridge up until 9/12/2020. Is that BM safe to give my baby? Or should I toss them and start freezing them straight away.
Hi Nanette, that should be fine. 🙂
Hi Amanda, I’ve been exclusively pumping since 5 weeks and my baby girl is now 3 months. I currently have a decent size milk stash in my deep freeze going back 2 months. I didn’t know much about rotating milk until this article. My question is can I use milk from 2 months ago to give to my daughter (3 months) or has her nutritional needs changed too much since then? I guess I’m wondering what the oldest milk you can give ? Is there a timeline ?
I will start rotating now ! Thanks for all the work you do in this topic!
You can! It’s totally fine. Read the first question at this link for more info!
https://exclusivepumping.com/exclusive-pumping-questions-lactation-consultant/
Hi!!
So my baby is 6 months. We just started him on solids three times a day with breast milk in between. My concern is I have about 2 month supply of milk in my freezer and I’m an exclusive pumper. When should stop pumping if he is going to be eating more solids? I plan on breastfeeding until he is 12 months. So Should I stop two months in advance to use the milk up or now just Incase he wants to stop breastfeeding early? I’m so lost.. clearly I have an oversupply due to pumping right after his birth and I use to pump every 2 hours.. now I’m pumping every 4 hours 5 times a day.. the bags of milk are 5-6 oz each session.
help please 😩
I would start to use it now (like one bottle a day), and then when it gets closer, you can decide to maybe wean early. I’ll put a link with more info on that below! Congrats on your 6 month old!
https://exclusivepumping.com/breast-milk-freezer-stash-calculator/
This article has been SO helpful! I plan on pumping for 6 months, or for as long as it takes to build a stash to last until my son is 1 (he is 2 months now). I’ve been able to build a fairly large stash so far because I’ve got a bit of an oversupply and we mix in formula at night. At the end of every day I take the excess milk and freeze it.
I haven’t started rotating any of it in yet because my original plan was to start pulling from the freezer once he hits 6 months. At that point the oldest milk will be 5 months old.
Is this an ok plan? Or should I start using some of the milk now?
Hi Christene! I would start using it now to make sure that you don’t have a lipase issue! Just like one bottle a day should be good!
Hi Amand,
Thank you for another informative entry – it is just what I need to read right now since my stack is slowly getting bigger.
Does refrigerating anf freezing milk kill out antibodies in breastmilk?
I’m using the pitcher method (thank you for that great information too!!). Would my baby receive less antibodies than freshly expressed milk?
Another question please: i would freeze my milk bag in the “normal freezer” about 2-3 days to get it flat first, before moving those bags to the deep freezer. Then how long can i keep those bags in the deel freezer? 6 months or 12 months?
Thank you for your time and dedication!
Hi Linh! Fresh milk is the best, but refrigerated and frozen milk is still perfectly good! 💜 if you only have it in the regular freezer for a few days, 12 months is fine.
I’m moving my stash from a regular freezer to a recently purchased deep freeze. Any ideas on how long I can store already frozen milk (some 4-5 months old) in the deep freeze? Thank you!
Hi Katharine! So the reason that the guidelines are longer in a deep freezer is that it’s not opened as frequently. It kind of depends on how it was stored in the regular freezer. Was the milk in the back, surrounded by other frozen stuff? Or do you have a toddler that keeps the freezer door open demanding popsicles on the regular? (Not that this happens in my house.) If the latter, I would try to rotate it out sooner rather than later. Hope that helps!
What if I am ready to stop pumping (or at least reduce sessions) and just sustain my baby from my freezer stash? I was hoping to give her BM for a year so I am trying to figure out how to make a stash for that and when I should quit pumping. I pump 5 times a day with at least 4oz on each breast. She is only 6weeks now but I am just looking ahead. Thanks
Hi! You can do that. I would rotate UNTIL you wean so that when you do wean, the stuff in your freezer is as “young” as possible. Does that make sense?
Any advice on moving a freezer full
Of breast milk for a 700 mile move to a new home?
Hi Holly!
This mom did it – check out what she did and the comments for tips!
https://www.instagram.com/p/B0i0mGsAF7B/
Hi Amanda
Does the lipase issue get worse the more the milk stays in freezer? For example will a 4 month old milk taste worst than a 2 month old milk ?
I think this can vary to person to person, but generally I would say yes. The longer after it’s been pumped, the worse it will be.
Very helpful information. Thank you!
I started a freezer stash when my baby was a month and a half old. He is now 3 months. I was told that I should use the milk from when he was a newborn now because it will not provide the nutrients he’ll need when he is older, say 5 or 6 months. Is that true?
I wouldn’t worry about it. See question #1 here:
https://exclusivepumping.com/exclusive-pumping-questions-lactation-consultant/
🙂
Hi, may I ask about freezer stash please.
while I was leave. I mostly pump now and then leave it to the next feed for my baby. So baby feeds on fresh pumps every day.
The balance milk from the pumping session will be put into fridge and then at the end of the day, I Will gather all the cold bm and then freeze it in about 4/5oz (quantity) per bag.
Reason being I had enough supply to feed my baby after each pump and still have balances. So with this over about 3 months I built up quite a big of freezer stash.
My baby was born in June. So now I am back to work, baby gets 2 fresh pump of bm from my wake up pump in the in the day. However, for the rest of the day baby drinks from my freezer stash. Now is the month of October and baby is feeding on my August frozen pump (oldest batch already). I am not sure if this is correct but somehow I have to use those frozen stash isn’t it? Otherwise the 3-6 months time limit will be up soon and my freezer stash will be wasted.
So the thing is so long I’m not at work such as on weekends. I’ll pump and feed baby fresh pump (not cold/frozen). Then the rest of the pump, I will have to freeze it. Only when I’m at work then I give baby frozen stash.
So based on the above, my baby on working days usually drinks bm that was pump roughly about 2 months ago.
Baby is feeding 150 every 3 hrs. His last feed for the day is about 9-10pm and first feed is about 5/6am the next day.
Is this arrangement alright?
That’s totally fine! No issues with what you’re doing. 🙂
Can you take Bm from deep freezer and put in freezer
Yes, that shouldn’t be a problem! I would just use the normal freezer guidelines then.
You can also donate it to hospitals.
Check out human milk 4 human babies!! Lots of people are looking for donations so you won’t have to throw it out. 🙂
Hi everyone.
I have a 13 month old who at about 9 months decided to not want any of my frozen milk still breast feeding but won’t drink and of the frozen stash i think i have around over 60 bags of 120ml each, it’s breaking my heart to throw everything away, was thinking of making icescream but don’t know how to thaw and re freeze any ideas please all appreciated. thank you in advance
For EPers, does the milk change with the age of the baby, I.e. do I have to worry about feeding milk from when my daughter was 1 month old to her when she’s 5 months old?
Hi Janine – it does change a bit, but not enough that you should worry about it at all.
I was wondering the same. My baby was very gassy and had an upset tummy throughout the day until about 8 weeks. I read about rotating your stash, so I’ve started that now at 12 weeks. I noticed she’s fussy again! I’m wondering if I should toss the earlier stash to avoid the tummy issues but I hate the thought of wasting so much milk. Is it possible the older milk is different and hurting her?
Side note: I thought it was the bottles for the longest time, but now I see it was the milk all along. Could have saved a lot of money trying all those different brands 🙁 argh!