How to Reheat Breast Milk: The Safe & Quick Method Everyone Can Use

So you have your breast milk stored safely in the freezer or refrigerator.

Now, what do you do with it?

Trust me: there is a right way and a wrong way to reheat breast milk. I’m here to tell you how it can be done correctly while maintaining maximum nutritional value.

The key is to heat it gradually and evenly, and definitely don’t overheat it.

Are bottle warmers really necessary?

You always have the option of buying a bottle warmer, but they aren’t necessary. I’ve personally never used one because I’ve mastered warming frozen or refrigerated milk simply by using water.

According to a 2015 study, bottle warmers have a tendency to overheat the milk, thus diminishing its beneficial properties.

Of course, whenever dealing with manufactured devices, always thoroughly read and follow the instructions, as every bottle warmer is different. Some heat the milk via steam, and some with water. The steam warmers use less water, but either way they get the job done.

The bottle warmer BabyGearLab recommends most is called Kiinde Kozii. Some of the valuable qualities they list include: “consistent, simple, user-friendly, and works with any bottle.” But the negative qualities listed are: “expensive, no end-of-cycle beep, and multiple cleaning steps.” No thank you.

How to re-heat your breast milk.

How to reheat frozen milk.

Ideally, move frozen milk from the freezer to the refrigerator the night before you intend to use it. It can take anywhere from 8 to 24 hours for milk to thaw completely in the refrigerator, so it’s best to have it working while you sleep. If you store your milk in 2-4 oz. batches, it will make the whole process go faster.
If you need to use frozen milk right away, place the milk container in a bowl or cup of cool water–not cold, and definitely not hot, just slightly cooler than room temperature. However, I’ve found that frozen milk quickly changes the temperature of the water to much colder, so come back and change out the water periodically.
Once the milk is thawed in the cool water, you can gradually increase the temperature of the water, but you don’t want it to go above 104 degrees Fahrenheit, according to BabyGearLab, or it will start to affect the beneficial antibodies that help your baby fight infections, etc. This is why it’s important to start with cool water and increase the temperature gradually. Even if you only increase the temperature to lukewarm, you’ll reach the right temperature. It only takes about 20 minutes to warm a bottle this way.
DO NOT REFREEZE THAWED BREAST MILK.

How to reheat refrigerated milk.

Some people recommend running water over the milk container, but I think that wastes too much water. My way involves a nice bath. Just place the container of milk in a bowl or cup of lukewarm water and wait about 20 minutes.
There is another option, which I don’t do: warming it on the stove. First, heat water until just before it is steaming. Then remove the water from the heat and place the container of milk in the hot water. You can reheat frozen or chilled water this way, but I think it sounds like too much trouble. You’d have to make sure not to overheat the water, and then you have to constantly check the milk to make sure it doesn’t overheat either because the water is too hot. But it’s another option if you want to try it.
NEVER HEAT MILK ON THE STOVE, AND NEVER HEAT MILK IN THE MICROWAVE. You will kill anything that was ever good about the milk.

Tip: I find that the cold temperature of the bottle changes the water, so check it periodically and change out the water for fresh lukewarm so it maintains its warmth.

The temperature to aim for.

How warm are we talking about?

Some babies don’t mind drinking their milk cold. You can try it and if it works, that’s great.

But I have a hunch that, especially in young babies under six months, cold milk could cause gas or tummy troubles, and warm milk just seems more comforting and soothing when trying to get your baby to sleep. So I recommend warming it to body temperature, if you have the time.

Once it’s warm, be sure to gently swirl the milk to combine the cream top with the more liquid bottom, as separation does occur during refrigeration/freezing, and it will also ensure that the heat is distributed evenly before you test it.

How do you know when you’ve reached the perfect temperature? Just put a drop on the inside of your wrist.

If it feels cold, warm it up a little more. If it feels warm, let it sit a bit to cool down. If it feels hot, definitely let it cool down before giving it to baby.

It’s very important that you’re careful not to scald your baby’s sensitive mouth and gums.

Always test the temperature on your wrist first! If you don’t feel any difference in temperature when the liquid hits your wrist, Goldilocks would be thrilled. It’s just right.

If you make a mistake.

What do you do if you heat the milk too much or too quickly?

Don’t throw the milk away! It’s easy to accidentally overheat your breast milk, and if it happens now and then, don’t worry about it.

There will likely still be some benefits to it, and it’s not going to be bad for your baby. Just learn from your mistakes and be more careful next time.

The only time you should throw your milk away is if it’s truly gone bad…and you’ll know if it has. Just like cow’s milk, it will look and smell horrid, and you wouldn’t dream of giving it to your baby.

However, don’t be alarmed if your breast milk has a funny smell after freezing. According to La Leche League International, this is due to milk fats breaking down from being frozen, and it will not harm your baby.

Once you get in the groove of warming/reheating your breast milk, you’ll see it’s a piece of cake.

Just remember not to shock the vitamins and minerals out of it by heating it too quickly, and always remember to gently swirl and test it before offering it to your cutie pie.

This way, you’ll have peace of mind knowing you did it the right way so your baby is getting the most benefits from your hard-earned liquid love.