How long to warm breast milk in hot water

When your baby wakes up and wants to eat right away, trying to get a breast milk bottle warmed up quickly can be really stressful. Today’s question is from a reader who wants to know if there is an easy, quick way to warm a bottle at night, when you’re half asleep.

Table of Contents Show

Fastest Ways to Warm Breast Milk for Night Feedings
1. Leave your freshly pumped milk out at room temperature after you pump it
2. Use a bottle warmer to warm the milk, with everything ready to go
3. Use hot water to warm the milk
4. See if your baby will take cold bottles (and skip warming altogether)
Can you warm up breast milk in warm water?
How do you warm breast milk when out?

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My baby is four months old, and has started sleeping longer stretches at night. I just dropped my middle of the night pumping session.

Is there an easier way to store the milk from my last pumping session of the day (around 10pm) until my baby’s first feeding at night (around 2am, sometimes a little later)? I’ve been using a cooler and warming the milk under the sink, but it seems to take a long time. Can breast milk be heated in a bottle warmer?

Yes, there is an easier way! Generally, I wouldn’t recommend warming milk by running it under water in the sink (unless you have no other option) because, as you said, it takes forever.

Here are a few other options that might work better.

Fastest Ways to Warm Breast Milk for Night Feedings

1. Leave your freshly pumped milk out at room temperature after you pump it

Whether this is a good option for you depends on:

How long your baby usually sleeps
How warm “room temperature” is in your house at night.

Kellymom defines “room temperature” as between 61 and 79 degrees Fahrenheit (16-26 degrees Celsius), and states that breast milk will be fine at these temperatures for 4-8 hours (though between 3-4 hours are ideal).

So, assuming your house is cooler than 80 degrees and the amount of time between when you pump the milk and when you feed it to your baby falls within that window, it should be fine to leave the pumped milk out at room temperature.

As an example, here’s what I did with my baby. I took a bottle up to my room after my 10 pm pumping session, and my baby usually woke up around 4 am to eat it. On the rare occasions that we’d both sleep until 6 am or later, I would dump the milk because it had been out longer than eight hours.

That’s one disadvantage of this method – you may have to dump your milk (or use it for a milk bath) if your baby wakes up later than normal for a feeding.

(One reader mentioned that she brings a small cooler to bed with her, with one bottle of fresh milk and the other refrigerated. She gives the baby the first bottle of fresh milk for the first feed, and at that time takes the other bottle out of the cooler, allowing it to warm up before the baby’s second feeding of the night.)

2. Use a bottle warmer to warm the milk, with everything ready to go

If using freshly pumped milk isn’t an option (for example, if you’re using a frozen stash or are supplementing with formula), another option is prepping the bottle ahead of time and keeping it in a cooler or mini-fridge in your room, along with a bottle warmer for night feedings that’s all set up and ready to go.

Then when baby wakes up, you just have to take the bottle out, put it in the warmer, press start and bounce your baby for a minute while it warms.

3. Use hot water to warm the milk

If you don’t have a bottle warmer, you can microwave a bowl of hot water for 60-90 seconds and put the bottle in that for a minute or so to warm.

This is less easy to do in the middle of the night with a baby to juggle, but it’s much faster than running a bottle under warm water in the sink.

Note that you should never heat baby bottles in the microwave due to “hot spots” that could burn your baby’s mouth.

4. See if your baby will take cold bottles (and skip warming altogether)

There’s no medical reason to warm breast milk, it’s just that some babies prefer it and get used it to warm.

So if your baby will take cold milk, you might just want to switch to cold bottles so that you can feed your milk directly from the fridge. This will make your life a lot easier (and not just at night).

It’s possible you’ve already tried this, but if not, give it a shot.

I would start by offering a cold bottle during the day (the middle of the night is not the time for experiments) and seeing if your baby will take it.

If your baby rejects it, you can try warming it a bit (maybe not as much as you normally would), and see if that is acceptable. If it is, you can see if gradually bringing the temperature down – until it’s not necessary to heat it at all – will work.

This won’t work for every baby – some will refuse cold milk, no matter what you do – and you may have to try this a few times under different circumstances. Try it with you offering it, with someone else offering it, when your baby is really hungry, when he’s not as hungry, etc.

Do you have any tips for quickly warming up bottles that I missed? Share them in the comments!

References

Bonyata, Kelly, IBCLC. “Human Milk Storage: Quick Reference Card.” https://kellymom.com/store/freehandouts/milkstorage01.pdf

Can you warm up breast milk in warm water?

Refrigerated human milk is best heated by holding the container of milk under cool running water and gradually adding warmer water until the milk is warmed to room temperature. If running water is not available, a pan of water can be heated on the stove.

How do you warm breast milk when out?

You can feed expressed milk straight from the fridge if your baby is happy to drink it cold. Or you can warm the milk to body temperature by putting the bottle in a jug of warm water or holding it under running warm water. Do not use a microwave to heat up or defrost breast milk.