How to Warm Breast Milk Safely

Once you’ve pumped and stored breast milk, what is the best way to warm it up before you feed it to your baby? Here is everything you need to know about how to warm breast milk.

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There’s nothing worse than trying to comfort a hungry baby while you wait for a bottle to warm up. So what’s the fastest way to warm a bottle of breast milk? Are all ways of warming it safe? Does breast milk even have to be warmed?

Does Breast Milk Have to be Warmed? Is It Okay to Give Baby Cold Breast Milk?

Because a nursing infant would take breast milk at body temperature (about 98 degrees Fahrenheit), it’s customary to warm breast milk or formula up to about this temperature before giving it to a baby in a bottle.

However, for the most part, warming up breast milk is more of a taste thing than a nutrition thing. You know how some people like leftover pizza cold and others will only eat it warm? Breast milk is the same way.

If your baby is less than a month old and is struggling with weight gain, warm milk might be a better choice as their body won’t have to work as hard to process it.

But after that, the only reason to warm a bottle breast milk is so that your baby will take it without any issues. If baby will happily take your milk cold (and doesn’t seem to have any problems with digestion afterwards), there is no medical reason you need to warm it. It’s fine to give your baby cold breast milk.

The one other benefit to warming breast milk is it helps mix the layer of fat that often forms on the top of the breast milk with the rest of the milk.

Warming Breastmilk Safely

Here are a few things to know about warming breastmilk safely.

Do not microwave breast milk – Microwaves don’t heat evenly, so there is no way to test the heated milk to make sure there are no “hot spots” in the bottle that could scald your baby’s mouth.
Don’t heat breast milk too hot – You want to aim for heating your breast milk to body temperature and preserve its nutrients.
Test the milk before feeding – Make sure you test the temperature before feeding it to your baby. You can do this by just putting a drop of milk on your wrist; the milk should be about the same as you body temperature when you give it your baby.

How to Warm Breast Milk – 4 Ways

If you decide to warm up your baby’s breastmilk, what is the best way to do it? Here are four options to consider, with the pros and cons of each.

1. Bottle Warmer

Using a bottle warmer can be the easiest way to warm breastmilk.

To use one, you usually just have to add water, put the bottle in the warmer, and then press a button that will start the heating process. Some bottle warmers will have a light that will switch on or off to let you know that the bottle has finished heating.

Some bottle warmers are a little fancier than others – for example, the Baby Breeza warmer has an app for your phone that you can use to start the warmer and be notified when the warming has finished.

Others are less elaborate – I used the Phillips Avent warmer, and it worked great.

2. In Hot Water

A bottle warmer is easy to use, but it isn’t necessary. You can also just use hot water to warm up bottles.

The way that I did this was to fill up a flat bottomed bowl about half way full of water. Then I put the bowl/water in the microwave for about 90 seconds.

When the water had heated up in the microwave, I took it out and put the bottle of breast milk in the water for a few minutes. (Be careful not to burn yourself with the water when you take it out of the microwave, because it will be very hot.)

Note: The exact times you’ll need to put the water in the microwave and the milk in the water will vary based on how much water you used and how much milk is in the bottle, so you might need to play around with them a little (and of course test before giving the bottle to baby).

When you’re out and about, you can ask for hot water at a restaurant or bring hot water in a Thermos to heat up a bottle.

3. Let it Come to Room Temperature

Another way that you can warm breast milk up is to take it out of the fridge and let it come to room temperature over time. (Note that this should only be done with breast milk that has not been frozen.)

To do this, just take your breast milk out of the fridge about 2 hours before you’ll need it. It will gradually warm to the ambient temperature; I did a test once and this took about two hours.

The breastmilk should be used within two hours of the milk coming to room temperature (so, about four hours after you take it out of the fridge).