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How To Freeze Breast Milk Flat (4 EASY Steps)

How To Freeze Breast Milk Flat (4 EASY Steps)
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If you are storing breastmilk, you may be wondering how to freeze breast milk flat. By freezing your milk in this manner, you can save a lot of precious space in your freezer.

Storing breastmilk can be challenging, especially if you’re building up a surplus. It can be refrigerated for up to four days.

But, if you put it in the freezer, you can store breastmilk for up to a whole year according to the CDC. Taking advantage of the freezer is a great way to solve the breastmilk storage problem, but even still, there’s limited space. 

But how do you freeze breastmilk, flat? Making sure your breastmilk bag is free of any air, and then laying it flat in the freezer is your best bet. Storing breastmilk in the freezer takes up less room, and once it’s frozen into a flat pack, you can move it to another spot in the freezer where it takes up even less space. 

But there are a few important guidelines to follow to make sure that all of those important nutrients are preserved within the frozen milk, and that no harmful bacteria finds its way inside. If you’re looking for a step-by-step guide on how to easily freeze breastmilk flat, stay right here. 

how to freeze breast milk flat. many frozen breast milk bags stored in the freezer to save space.

The Easiest Method For Freezing

The idea behind freezing breastmilk flat is to not waste a drop, but also to make it easy to access and store.

Once you have a little stockpile of neatly frozen flat baggies of milk, you can have a fantastic filing system that just makes it so easy to use. But more on that later. 

Even more importantly than the ease of storage and accessibility of frozen milk is the fact that frozen milk does retain some of the healthy fats, nutrients, and antibacterial properties that are found in fresh breastmilk.

So, if you have milk that might not get used within the next four days, go ahead and freeze it.

What You’ll Need

Of course, before you get started, you’ll want to have all of the supplies ready to go. If you are brand new to the pumping world, you already know that there’s not a lot of mobility during the actual pumping process.

I use an awesome gadget to make sure my milk is super flat each time. Check it out here (on Amazon).

It helps to have an area with all of these supplies, ready to go each and every time.

  • Your pump of choice and all of the parts that come with it 
  • Sanitizing wipes for the pump
  • Hand sanitizer
  • Permanent marker
  • Masking tape 
  • Milk storage baggies (these are my favorite from Amazon)

4 EASY Steps to Freeze Breast Milk Flat

Navigating the breastfeeding world is challenging, especially with a brand new baby. To make it a little easier, here’s a step by step guide of what you can do to freeze your breastmilk bags so they are flat.

Step 1: Wash & Pump

Washing your hands too much is not a thing when it comes to pumping and storing. The more sanitary the operation, the less likely it will be to have a compromised milk supply.

Starting with clean pump parts and clean hands is a must. 

Step 2: Label Baggies

While you’re pumping, go ahead and use the permanent marker to label the date and time of the session. Avoid touching the opening of the storage bag, and the inside too.

Most storage bags have a spot to do this. However, this can rub off, so it’s a good idea to use masking tape as a backup label.

There’s nothing worse than having to toss out a bag of milk that you worked so hard for, just because you can’t read the label. Keep the date and time close to the top to make it easy to see later. 

Pro Tip: If you are pumping and storing a lot of milk, you can use color-coded stickers for each month to keep your stash organized. So the first month you store milk, put a blue sticker on all your bags. In the second month, use a yellow sticker (and so on). Here are my favorite stickers for this method (link to Amazon).

Step 3: Transfer Milk

Again, sanitize first. Use the hand sanitizer and wipe down the outside of the baggie just to ensure it is extra clean.

Again, steer clear of any part that will actually touch the milk while it’s in storage. Outside substances will affect the quality of the breastmilk during the freezing process. 

Pour smaller amounts of milk into each bag. This might seem tedious at first, but it will cut down on waste later as your baby starts to need more.

Just four to five ounces per bag is a great option in the beginning. You can always thaw more, but refreezing is not an option once the milk has thawed.

So, thawing too much and having it not get used means it has to be thrown out. 

Step 4: Seal & Store

Before sealing the baggie, carefully hold it upright and help press out any extra air. Then, seal the bag.

It doesn’t hurt to double and triple check to make sure the seal is extra tight. Spilled milk is actually something to cry over when it comes to breastmilk. 

Find a place in the back of the freezer to flat freeze your milk. Keeping it away from the door will protect it from any temperature fluctuation when the freezer is opened. 

Using a flat surface, like a plastic container or baking pan for the initial freeze can help the milk freeze as evenly as possible. It will also make it the perfect size and shape for long term storage. 

This pan is actually the perfect size for freezing breast milk bags flat in your freezer (link to Amazon). As a bonus, you can use it in your kitchen once you are done with your breastfeeding journey!

If your freezer space is limited, like mine is, then it is really helpful to get the milk bags as flat as possible. This little gadget is worth its weight in gold to make sure every milk bag is super flat.

It works well with Lansinoh bags, Parent’s Choice bags, and even the Medela and Kiinde bags if they are not too full.

Keeping Frozen Milk Organized After It Is Flat

Once your milk is frozen flat, you have the option to move it to be stored upright. There are plenty of super useful storage containers that can help you organize your flat frozen breastmilk for the easiest access ever. 

Once a new baggie is frozen solid, you can simply add it to the back of the pack. As long as the dates are written near the top, you’ll be able to see them clearly. 

If you keep with this system of adding new bags to the back and taking the first one in the front to thaw, your milk will stay organized.

You’ll be able to quickly rotate and use your oldest milk first. This is important due to the limited amount of time frozen breast milk will last in the freezer.

This system makes flat freezing your breastmilk a piece of cake. It will hopefully be one less thing you have to think about during the ever so complex journey of breastfeeding.

Why Freeze Breastmilk

As we mentioned, frozen breastmilk is a great way to store any extra that you’re producing while pumping.

And, of course, having frozen milk on hand is perfect for a grab and go situation, or if you’re going to be away from your baby and you need to leave some milk with a sitter. 

Whatever the case may be, having a frozen supply for feeding is fantastic. Once again, anything that makes life easier while breastfeeding a newborn is always a bonus.

But, frozen breastmilk can also be used for a few other things besides feeding which I describe below. 

4 Handy Uses For Frozen Breast Milk

If you have plenty of milk for feeding your baby, you may wonder what you can do with the leftover frozen breastmilk. Here are a few things you may want to use it for:

  • A milk bath for baby
  • Mixing with baby food when introducing solids
  • To help with teething
  • As a home remedy for mom’s skin

As a side note, use caution when using breastmilk for home remedies that aren’t topical.

Breastmilk can cause damage if it’s put directly in eyes, ears, or the nose. Before doing anything that involves more than putting breastmilk on skin, remember to ask your doctor. 

A Milk Bath For Baby

Babies can have some crazy things going on with their skin. Adding a few ounces of breast milk to their bath may help with some minor skin issues.

  • Minor rashes and irritations
  • Cradle cap
  • Dry and peeling skin
  • Infant acne
  • Eczema

You only need to mix a few ounces of milk in with baby’s bath water to get some of the benefits.

Gateway Food To Mix With Solids

Adding breastmilk to solids as you start to introduce them to your baby’s diet can be really helpful. It’s a taste they’re familiar with, so it can help them become familiar with new foods. 

Mixing breastmilk in with other solids can also help make them easier to chew and swallow. Some good foods to try this with are baby oatmeal, mashed up bananas, or steamed and cooled carrots.

Sure, water can be used here too, but why not add some of that nutrition from the breastmilk that you’ve been cleverly freezing.


This can be a scary time for parents… and babies. Breastmilk popsicles can be helpful to relieve some of the pain that comes with cutting teeth, making babies feel better and hopefully giving parents a little break from the fussiness that comes along with this phase. 

Mom’s Skin

Let’s be honest, pregnancy hormones can also do a number on mom’s skin, too. Using breastmilk as a face wash can help with acne, redness, and other skin conditions that are postpartum related.

Also, frozen breastmilk on sunburns, bug bites and even poison ivy has been known to take some of the sting out. It’s even been thought to help with stretch marks. (It is important to note that this is anecdotal, however, and hasn’t been proven in any official study.)


Storing frozen breast milk can be done in a few different manners. If breast milk is frozen flat, then it will save a lot of space in your freezer.

In order to freeze breast milk flat, be sure to use a durable milk storage bag and squeeze all of the air out of the bag. Then, lay it on a flat surface while freezing. The bags can then be stored upright in the freezer after the initial freezing step.

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NEXT, Check Out

  1. The BEST Method To Pump Milk For Daycare
  2. Is it better to store breast milk in bags or bottles?
  3. Is It Ok To Have Air Bubbles In Frozen Breast Milk?


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