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Is It Okay to Have Air Bubbles in Frozen Breastmilk?

Is It Okay to Have Air Bubbles in Frozen Breastmilk?
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You spent all that time pumping and freezing breastmilk. When you go to get the bag out of the freezer, you may be curious to know if it is ok to have air bubbles in frozen breastmilk.

Everyone wants to provide the best nutrition for their growing bundle of joy, whether they opt for formula or for breastfeeding.

But when it comes to breastfeeding, things can become a little challenging when it comes to storage and freezing milk. Fresh breastmilk can separate, giving it an odd appearance, or appear frothy, which can make a mother wonder if it has spoiled.

Since both of these questionable characteristics are safe, are air bubbles in frozen breastmilk harmless, as well?

Is it okay to have air bubbles in frozen breastmilk? No. You should avoid air bubbles in frozen breast milk as much as possible. This extra air can cause freezer burn on the breast milk.

After breastmilk has defrosted, air bubbles in the defrosted milk can cause tummy troubles for your baby, including excessive gassiness and even colic.

You should always minimize the amount of air in your breastmilk storage bags and containers as much as possible.

Whether you’re trying to build up a frozen breastmilk stash for a weekend getaway with your partner or need a large stash for your return to work, you need to know the facts when it comes to air bubbles.

Below I will go into detail as to why you should avoid air bubbles in your freezer stash, and how you can prevent this situation altogether.

air bubbles in frozen breastmilk. baby hand with bag of frozen breastmilk

Is It Okay to Have Air Bubbles in Frozen Breastmilk?

One thing you might notice when you’re storing your breastmilk in the freezer or thawing it for use is air bubbles. This is a fairly common thing that many women experience, but it’s completely avoidable — and should be avoided at all costs. But why?

Air bubbles in frozen breast milk can lead to freezer burn on the milk. If the milk is stored in the freezer for a short period of time, like a few weeks, you probably will not experience freezer burn.

But if the frozen milk is stored for a longer length of time, like up to six months (per CDC guidelines), then you are at risk of freezer burn on your milk.

After the bag has defrosted, you also want to avoid air bubbles in the milk. This can lead to the baby sucking in too much air while feeding.

The extra air may become trapped in their sensitive digestive tract, which causes excessive gassiness, fussiness, and pain.

In some cases, babies may even end up with dreadful colic that can leave them almost inconsolable as their tummies hurt considerably worse. 

It’s incredibly important to take the correct steps towards minimizing air getting trapped in your breastmilk storage containers. 

How to Prevent Air Bubbles in Frozen Breastmilk

Breastmilk bags are the number one choice for storing breastmilk in the freezer. This is because they allow for more storage space since they don’t take up as much room as a container.

Additionally, you don’t have to worry about bacteria or other types of contaminations from a storage container as breastmilk storage bags are made explicitly for the sterile storage of liquid gold.

Another reason why breastmilk bags are recommended is that it is far easier to ensure there are no air bubbles in a bag than in a container.

This gives moms some peace of mind knowing that their baby isn’t as likely to end up with tummy troubles from consuming too much air.

So, how can you avoid air bubbles in frozen breastmilk? The process is actually very simple.

Keep in mind, though, that many women prefer to pump into a storage container before transferring to a storage bag. This provides more stability and avoids accidental spills.

Supplies You Will Need

1. Breastmilk Bags For Freezer Storage. I used this brand because they could be frozen very flat, and they saved a lot of space in my freezer. Here is a link to the breastmilk bags that I use (link to Amazon).

Side Note: The bags would occasionally leak when I went to defrost the milk, so I would always defrost the bag of frozen milk in a cup in the refrigerator to catch any droplets.

2. Freeze Flat – This is an awesome gadget (link to Amazon) to make sure your breastmilk bags are as flat as possible when they are in the freezer. This helps to minimize any air bubbles!

Pro Tip: To minimize transferring from breastmilk bags into bottles, you can pump directly into bags using an easy system. You can get a FREE sample kit on their site here and only pay $6 for shipping.

Step-By-Step Instructions For Freezing Breast Milk

To lessen the chance of air bubbles forming in your breast milk, follow these steps:

1. Start by pumping into a storage container. Your breast pump likely came with a few containers to pump directly into. Make sure to boil the containers before use for sanitation purposes.

Pro Tip: Label the breastmilk bag with a Sharpie before you begin transferring the milk from the bottles into the bag. This will definitely save you some aggravation!

2. Use a flange to pour the breast milk into the storage bag. Again, this is simply because it’s easier than trying to pour the milk into a floppy bag.

Your goal is to avoid spills or leaks during transfer, and it’s easiest when done using a flange. Be careful not to overfill as breastmilk expands when frozen and it could tear the bag.

3. Starting at the breast milk, squeeze your fingers tightly around the bag and move upward. You are trying to pull out any of the excess air that may be in the bag. Your fingers should resemble a pair of scissors.

4. Continue on one side of the bag, then partially zip. Once you feel confident that one side of the bag is air-free, then zip the bag halfway. This will help to tighten the seal and keep air from coming back in.

5. Start squeezing the other half of the bag. Using the same scissor technique, start on the other side of the bag and squeeze the air out of the top. 

6. Zip the bag closed. But don’t just zip it once or twice and be fine. You want to run your fingers over the zipper at least five times to ensure it is locked in place.

Breastmilk bags are notorious for leaks because women don’t take the time to ensure the bag is zipped and sealed entirely. This leads to a loss of milk as well as potentially contaminated milk.

7. Place the breast milk bag on a flat surface in your freezer, like the freeze flat. This will help to ensure you save the most space in your freezer.

After the milk has frozen (usually within a few hours), you might consider adding a container to the freezer. One that works well is an empty 12-pack soda carton. This will help the milk bags remain upright and to keep your stash organized. 

It’s a straightforward process — your goal is to remove any air within the bag.

For a visual step-by-step guide on how to avoid bubbles in your breastmilk, check out this helpful video. 

Safety Tip: Remember to follow CDC guidelines when freezing breast milk. A few of the most important guidelines are:

  • Never re-freeze thawed milk.
  • Once thawed, milk must be used within 24 hours
  • Freshly pumped milk that has been frozen is good in the freezer up to 12 months. However, it is best to be used within 6 months.

The Right Bottles Make a Difference In Air Bubbles

The other thing you should concern yourself with is the bottle that you are using to feed your little one.

Even if there might not be any air bubbles in your frozen breast milk, that doesn’t mean that your baby won’t end up gulping down too much air.

Any type of excess air leads to tummy troubles, and you want to avoid this at all costs.

Therefore, it’s important to find a baby bottle that doesn’t lend itself to too much air intake when the baby is feeding.

My top two picks include:

Philips Avent has long been a top choice for moms everywhere. These top-of-the-line bottles are highly rated and well-reviewed, so you know you can trust them. They are affordable as well, which is always a bonus.

This bottle from Philips Avent has been clinically proven to reduce colic and discomfort in babies, which is a common occurrence for babies who suck in too much air while feeding.

It is designed with an anti-colic valve built right into the nipple which prevents air from entering the bottle entirely. 

With this bottle, your baby will feel full and happy — with no signs of excessive air or tummy troubles in sight.

Dr. Brown’s glass baby bottles are made from high-quality and durable materials and are positively reviewed, so you know they are bottles that you can feel confident in.

These bottles are also designed with an anti-colic feature built right into the design, which means less air being inhaled and a better feeding for the baby. 

Another significant benefit of this bottle is the unique shape of the nipple. This may be the better choice for breastfed little ones who want to feel like they’re getting the “real deal”.


Air bubbles in frozen breastmilk can lead to freezer burn on the breastmilk. If there are any air bubbles once the milk has thawed, they can lead to fussiness and gassiness in your baby.

The good news is that air bubbles can be avoided by using breastmilk storage bags and the scissor technique to remove air.

Using anti-colic bottles in conjunction with storage bags will provide the safest feeding experience for your baby – without any air!

More Pumping Tips

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NEXT, Check Out These Articles

  1. How to Pour Frozen Breastmilk From Bag To Bottle (7 EASY steps)
  2. How To Use Breastmilk Bags & How Many Do You Need
  3. How To Pack Baby Bottles For Daycare


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