Storing Breast Milk in Glass Containers

A few months ago I posted a personal reflection, “Breast milk Meltdown” about how after storing a whole month’s supply of breast milk diligently for my son, it was all ruined in an instant.

Since that post, I have received quite a few questions in regards to the type of glass containers I used, tips, tricks and so on.  So I wanted to consolidate my advice into one post, in case there are other mommas out there wondering the same things.

Glass Container Information:

You can store breast milk in any freezer safe glass jars, however I prefer to use 125ml {4.2 oz} canning jars, like the Ball Quilted Jelly Canning Jar 4 Oz (Pack of 12)

Storage Portion Size

125ml is the perfect portion size for freezing breast milk.  You do not want to thaw too much breast milk and have it go to waste, because if your baby does not consume all of the thawed milk, you will have to throw it out.  Thawed breast milk CANNOT be refrozen!  Therefore this small size is ideal.  If your baby finishes the entire contents of the bottle and is still looking for more, you can quickly and easily thaw another jar of milk.

Thawing Frozen Breast Milk in Glass Containers

There are several ways of thawing breast milk that has been frozen in a glass container.

(1) Leave the glass jar on the counter to thaw.  1-2 hours.

(2) Place the glass jar in the fridge to thaw.  Several hours up to 1 day.

(3) Place the glass jar in warm water to thaw.  10-20 minutes.


Helpful Extras:

Breast Milk Freezing Time Guidelines

Freezer inside the fridge: 2 weeks.

* Self-contained freezer: 3-4 months.

* Deep-freeze: 6-12 months.

Reusing Glass Mason Jars

One of the best parts about using these glass containers for storing breast milk, is that once your little one is no longer nursing, or if you have some spare jars laying around, you can use them for baby food!  Same as with the breast milk portion size, the 125ml jar is perfect to store small quantities of baby food.  Your little one will probably eat anywhere from 1-2 jars of baby food per feeding, and this way you can easily quantify just how much food they have consumed.


  1. says

    I can’t tell you how thankful I am for this post!! I am not a regular ‘pumper’, Ben is always ALWAYS with me so I haven’t had to more than a coupe of times, but I need to be able to do this more so that I can have a little bit of independence! I’m bookmarking this right now!!!

    • Bluebird Kisses says

      Having a few extra bottles stored is really great. It also can give you a bit of peace of mind incase for whatever reason the supply diminishes…mine every once in a while would go down and I loved having the milk available to use in case of an emergency.

      You can pump after Ben goes down for bed at night. Say he usually sleeps from 8pm – 2am, just pump at 9:30 or 10pm when you’re ready to go to sleep. That way you’ll have enough time to replenish the supply before Ben will need it again. Or as an alternate, you can pump after the early morning feeding when your body has a bit of excess.

  2. says

    This is a great post, thank you for elaborating on your last one about this! I definitely want to do this, we are buying a storage freezer for our basement soon and I found the jars at Walmart yay!

    I do have one question for you though: the thawing times above, it seems that that would be enough to unfreeze the milk. Do you then heat it up on the stove to warm it up for baby or do you feed it to him cold? Sorry for the dumb questions, newbie here! 😉

    • Bluebird Kisses says

      Not a dumb question at all! Actually the answer is it depends. Sometimes during the day he gets it colder, but in the evening we always heat it up. To heat it we place it in warm water just the same as you would with refrigirated milk, and test it to see when it is ready. I find about 5-8minutes for a 5oz bottle that’s completely thawed is enough.

      That’s so great about the storage freezer! I’d love one like that, even for baby food down the road its amazing.

  3. Sally says

    Are Ball canning lids now BPA-free? I read a few months back that the lids had a BPA coating. I am looking to use glass to avoid chemicals in plastics.

    • Bluebird Kisses says

      Hi Sally, thanks for stopping by. There are in fact PBA free canning lids, not all are, so you have to be careful. But here is a link for you:

      also, even though the lids I use are pba free, I’m still not convinced that there might not be other chemicals in there that are bad, so I make sure to not fill the jars completely full. I fill them about 2/3’s of the way only. The milk will expand during the freezing process and this will ensure that its not actually touching the lid.

  4. Angela says

    Just a couple questions: Do you reuse the lids then since it’s not a traditional “canning” process where lids are just one time use? Do you still use the rubber rings or just the lid and metal ring?

    • says

      Hi Angela, I personally reused the whole lid because I didn’t actually “can” the milk…this was for milk that was frozen for a shorter period of time {I’d write the date the milk was jarred on the top of the lid}. With that said, milk that was used after a couple of months I kept the jar but threw out the actual lid since I thought it wouldn’t be good anymore.

  5. Juliana says

    Hello! This is an old post, but I hope you still monitor comments 🙂
    I was wondering,,, Do you close the lids without vacuum? Or do you use some type of canning technique?
    I just ordered the ball 4 oz jars and the bpa free Tattler lids! Looking fwd to building my breast milk storage!

  6. Kayla says

    Wow! Awesome post! Thank you so much for sharing! This will be very helpful as I was afraid I couldn’t use glass (blugh plastic) due to expanding.

  7. Laura says

    Thank you so much for the info. I was feeling overwhelmed trying to find solutions to freeze my milk and not use plastic.

  8. Nancy Loane says

    Hi there!!! Thanks so much for creating this post. I hope you are still answering questions. I am going to be a first time mom and currently I am overwhelmed by so many other factors (e.g. giving birth).

    I am following your advice and I’m running out today to purchase the freezer safe jars. However, I am hoping you can share more details about your milk storing practices.
    1. How many 4.2oz jars do you suggest I purchase?
    2. How do you date/label them?
    3. I am confused about the lid discussion posted earlier regarding the limited life of metal lids due to toxin buildup. Can you clarify the difference between mason orignal metal lids vs. Tattler lids? How often do you re-buy the original mason lids?

    I learned that Ball and Kerr jars are 4oz and freezer safe and they come in Regular Mouth size with metal lids. You can purchase separately the Ball plastic caps for freezing which are BPA free. I sounds like these jars are also doable don’t you agree? Check out the link:

    Sorry for so many questions, you know what your doing and I’m all about asking the experts:)

    Happy Wishes!

  9. Rachel Orke says

    Thank you so much for your post. It is amazing what a lack of info there is about breast milk storage. I want to store breast milk for when my little one gets to eating solid foods. I would like to make oatmeal and other foods with the breast milk. I heard that in the freezer the milk lasts 4 months. Are you saying the standard freezer attached to fridge is only 2 weeks?

    I had a similar freezer malfunction and lost the first batch of frozen breast milk. I thought back to having read your other post and felt that I was not alone. Thank you for sharing. Community is important!

    • Jenn Durham says

      this is old and you might not care about the answer anymore but i thought i would answer just in case someone else was having the same question. you know how there are refrigerators that have this little box that is there “freezer” well in there it would last two weeks. if you have to open a door to get to the freezer then it will last 3-6 months. and a deep freezer will last 6-12 months. the milk should always be kept in the coldest part of the freezer or fridge (so not the door). the more that you open the door the warmer that you keep the freezer so the time will go toward the lower end. if you never open the deep freezer then it could last one year.

  10. krystle winter says

    Can you please tell me how you sterilize your mason jars. I have an advent microwave sterilizer but obviously I cannot sterilize the lids in the microwave. My other question is, do you reuse the lids?

  11. Min says

    Fantastic post and I can even buy the jars in Australia. Just a quick note for all those people asking questions about BPA free. The alternative coatings are usually still of the bis phenol family and/or contain endochrine disrupting properties (which is why you’d be avoiding BPA in the first place). the ED chemicals only leach into foodstuffs if they have contact with them so it should be ok to just not fill the jars to the top

  12. Paddy says

    Is there a way you can attach a nipple to this and directly feed from this instead of transferring to another glass bottle? Any recommendations for a nipple?

  13. Kara says

    I recently bought a bunch of mason jars and plan to freeze my milk in them. I’m trying to figure out the best way to close the jars. I purchased BPA free plastic lids for the jars and I also purchased silicone round disks that can be inserted inside of the metal lids that come with the mason jars.

    The manufacturer says that the metal lids are intended only for using one time because they lose their seal after one use.

    Do you have any knowledge about what is the safest way to seal the mason jars? Thanks!


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