7 Important tips to safely handle thawed breastmilk

how to safely handle thawed breastmilk

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So you have a stash of frozen breastmilk – and you worked hard to get it. That’s no little thing! But let me ask you this. Did you know that there are a few rules to follow to safely handle thawed breastmilk? Do you know how to keep it safe once you thaw it?

What if that milk had a little bit of history before you froze it? Like 4 hours on the counter (because life happens sometimes) and then 3 days in the FRONT of the fridge. You debated about even freezing it, but you hated to throw it out.

Now do you know how to keep it safe for your baby? Tricky right?!?

Thawing breastmilk

I know you don’t want to hear this (most of us aren’t super-organized, type-A people whose days are planned in 5-minute intervals), but you need to plan ahead on this one thing.

Because when it comes to thawing breastmilk, the slower the better.

Ideally, you want to do it without adding any heat because heat melts milk fat. So then you have sticky, melted fat stuck to the storage container instead of staying in the milk.

And what you end up with is a lower-calorie, less nutritious breastmilk.

Your baby desperately needs that fat! Even if she’s a chunky little monkey.

The best way to thaw breastmilk

The absolute best way to thaw milk is by putting it in the refrigerator to thaw ever so slowly.

Here’s the ideal scenario:

* you’ll slowly bring frozen milk to room temperature
* then transfer it to the bottle your baby will use
* then warm it with a bottle warmer or a bowl of very warm water

BUT if you’re like me, then you won’t think a thing about thawing it until you need that chunk of frozen milk to be warm in a bottle. Like right now.

The second best way to thaw breastmilk

So the second-best option is to lay it out on a towel and let it come to room temperature. That’ll take somewhere around a half-hour. Also not very helpful when your baby is hungry.

Or if you have “mom brain” and sometimes forget what you’re doing. You might wanna set a timer, just in case.

An even quicker option is to hold it under warm – not hot!! – running water or set it in a bowl of warm water. Make sure that the water stays warm. Using this method, it’ll thaw out in less than 5 minutes. (which feels like a year in screaming-baby-time)

Don’t microwave your breastmilk!

We’ve all heard that you shouldn’t microwave breastmilk. Let me just admit now that I’ve totally thawed breastmilk in the microwave before. Even though I was told not to. I’m a rebel like that.

I thought the only issue was “hot spots” and that I was grown up enough to stir the milk to an even temperature. But it turns out, that isn’t the only issue with microwaving milk.

I wish I could go back in time and talk to my uninformed self about how to handle thawed breastmilk.

Microwaves change the composition of breastmilk. They damage the vitamins and white blood cells in your breastmilk. Not to mention, they melt that milk fat and cause it to stick to the sides of the container instead of nourishing your baby.

Don’t microwave breastmilk. Please.

Handling thawed breastmilk

Always wash your hands before handling breastmilk. Even if you have absolutely no intention of touching the milk with your hands. Keep in mind that germs can float in the air, so you don’t necessarily have to put a dirty finger in the milk in order to contaminate it from unwashed hands. 

Since every surface has its own troop of microbes, pathogens, bacteria, microscopic fecal matter, and probably viruses (am I grossing you out yet?) it’s best to limit the number of times you transfer breastmilk.

You can handle thawed breastmilk too much

Breastmilk is full of white blood cells. I mean absolutely loaded with ’em – to the tune of millions! These white blood cells play a couple of different roles.

  • First, they keep breastmilk pure by fighting off any harmful bacteria that the milk comes into contact with.
  • And second, they keep your baby healthy by fighting off infection and bacteria in her little body.

Here’s the kicker: white blood cells aren’t invincible. They can only fight for so long before they die.

So each time you transfer milk from one container to another, you introduce it to new dangers that it has to fight off. Which leads to the demise of white blood cells. Which means your baby gets fewer of these immune system warriors.

The less you hand thawed breastmilk, the better!

If you can get a system like the Kiinde system, where you pump directly into the container that goes into the freezer — and then becomes part of the bottle — it would be ideal. Because you never have to transfer milk out of that one container, all the fats and nutrients stay in place and your risk of contamination is super-reduced.

Can you refreeze thawed breastmilk?

Nope. Never.

BUT but but but but but…if your milk accidentally thaws most of the way, you can refreeze it. If there are still ice crystals in the milk, it isn’t considered thawed yet. So if that’s the case, you can absolutely refreeze it.

How long is thawed breastmilk good in the fridge?

You can keep thawed milk in the refrigerator for 24 hours.

After 24 hours, it’s not spoiled per se… but your baby shouldn’t drink it.

It would still be good to use topically to heal wounds. Or it would be great in a milk bath.

And if you’re a crafty kind of mom, you could still use it for milk crafts.

Milk looks or smells funny after thawing

Thawed breastmilk looks and smells different than fresh breastmilk. Always. Freezing changes the composition of milk – and the way it blends together. So the texture will be different.

I’d hate to know how many ounces of milk I wasted because I didn’t realize that. I poured several bags of thawed milk down the drain because I thought they were spoiled.


The bright side is that now I can tell you about it so you don’t act stupid make that mistake too.

The most common issues you’ll notice with handling thawed breastmilk is that it smells weird and it looks strange. The texture of it might bother you too.

The milk smells soapy

Sometimes thawed breastmilk smells off. And that’s kinda scary.

So here’s the deal: if milk that was properly stored smells soapy or weird, it’s safe to drink.

If it smells rancid, putrid, or like spoiled milk, it’s not safe to drink.

The weird smell in thawed breastmilk is caused by lipase. Lipase is an enzyme in your breastmilk that helps your baby digest milk by breaking down fat.

What to do about weird-smelling breastmilk

It’s not dangerous at all for your milk to smell a bit weird. And believe it or not, your baby won’t object either.

If the lipase smell bothers you, you can blend this milk with fresh, cooled breastmilk. It doesn’t fix the smell, but it does dilute the smelly milk so it’s not as noticeable.

If you want to prevent this smell, you can scald your breastmilk. KellyMom has a great article that explains how to scald breastmilk. Note: it won’t fix milk that already smells off, it just keeps that from happening to freshly pumped milk.

The breastmilk smells like sour milk

Ask yourself for real here – does it smell sour or just not great?

That’s an important distinction because it’s normal for thawed breastmilk to smell “not great.” That’s caused by an enzyme that helps break down fats. And “not great” smelling breastmilk is very much safe and healthy for a baby to drink. Believe it or not, most babies don’t seem to even notice.

But it’s not normal for thawed breastmilk to smell sour or rancid.

If your milk smells that way and you’re absolutely sure it was properly stored, then thaw another container of milk from a different date. Does it smell the same? If so — and if the smell isn’t actually putrid, like cow’s milk way past the expiration date — then that’s probably just the way your milk smells when it’s thawed.

So here’s the takeaway: if it smells weird, it’s safe. If it smells rancid, it’s not.

Breastmilk looks weird

Once breastmilk is frozen, its texture changes. It’s going to be like a whole different substance when you thaw it out. So aside from any weird smell, it may also separate. It may look greasy in spots, or like there are layers to it.

One layer may look thick – creamy if you will. The other layer really thin and watery. Totally normal. Perfectly safe.

If you see clumps, lumps, globs, etc. it is NOT safe. Throw it out!

Just Remember

Breastmilk is hands-down the most nutritious, wonderful thing you can feed your baby. Your body actually customizes breastmilk to fit a baby’s individual nutrition needs! And while breastmilk is robust and strong, it’s not invincible.

So take care to follow these tips for optimally healthy milk:

  • Store your milk in containers made for breastmilk
  • Follow guidelines on how long to store your milk in the refrigerator and freezer
  • Thaw it out slowly
  • Never microwave your breastmilk
  • Don’t re-freeze breastmilk that was fully thawed
  • Transfer the milk between containers as rarely as possible
  • Weird-smelling milk is safe, foul-smelling milk is not
  • It’s normal for milk to separate after thawing – it’s still safe to use

I recommend reading this article a couple of times. Bookmark it if you need to. Print it out and put it in the bag with your breast pump so you’ll remember how to handle thawed breastmilk. Storing breastmilk isn’t hard, but there are very definite rules you need to follow. Once you know them, you’ll be confident that every bottle of expressed milk your baby gets is as safe and nutritious as possible.

Did any of these tips surprise you? Or do you have a horror story of breastmilk you had to throw away? Please share them in the comments below!






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