Baby bottle placed in a baby bottle warmer, next to other bottles on the table in the background

How To Warm Baby Bottles The Safe & Easy Way: 5 Methods

Babies are impatient creatures. When their little tummies require a refill, a chill demeanor quickly turns into ear-splitting cries!

I guess we’ve all been there – a baby crying inconsolably, a parent rummaging through feeding gear to get a feed ready at lightning speed – a spill or two courtesy of blind panic which cues in more crying, because mommy, you’re taking too long!

The good news is that feeding your baby doesn’t have to be this stressful at all!

Baby bottle placed in a baby bottle warmer, next to other bottles on the table in the background

When it comes to bottle feeding – specifically, warming the milk up – there’s a hearty serving of inconsistent advice out there (and a lot of it is plain out bad advice), leaving many parents at a loss on how best to go about it.

In this article, we’ll go over what authoritative voices on the subject have to say about right and wrong practices, and we’ll also talk about a few tips from personal experience.

Here’s your go to guide on how to warm baby bottles!

How to Warm a Baby Bottle

First things first, know that it’s not a must to heat your baby’s breast milk or formula.

Some babies are happy to drink cold milk, while others prefer warm formula. It’s a matter of personal preference that you’ll have to find out on your own with your baby, by trial and error.

We weren’t lucky enough to have such babies ourselves in my family, so we did have to heat bottles in the four years we’ve been parenting. Hopefully, you will be (or already are) luckier than us!

The ideal milk temperature is at or just below body temperature, which is 98.6 degrees Fahrenheit.

This is not a hard and fast rule, though. You may find that your baby prefers warm milk or sleeps more soundly after a nice, warm bottle of liquid gold.

And why not? We’re not ones to drink coffee at room temperature, either!

The Food and Drug Administration (FDA) outlines two possible ways of heating formula or breastmilk in hard plastic and glass bottles:

In Hot Tap Water

Place the bottle under hot, running tap water for one to two minutes, or until the desired temperature is reached.

Be careful not to scald yourself!

On the Stove

Heat some water in a pan.

Once hot enough, remove the pan from the heat and place the bottle in it.

Wait until it’s warm.

In a Jug or Bowl

Fill a jug or bowl with water that’s hot enough to warm the bottle, but not too scalding that you cannot put your hand inside.

Leave the bottle in the warm water for not more than 15 minutes. If you leave the bottle inside for any longer than that, bacteria can develop.

The bottle should be sealed with a cap over the teat while it’s heating.

Use an Electric Bottle Warmer

This was our go-to option with both our kids, as it’s the easiest and most straightforward option overall.

Simply place the bottle in the warmer and follow the manufacturer’s instructions.

There’s a huge selection of bottle warmers available out there for you to choose from. We preferred to opt for one that heats up milk quite fast, as no baby wants to wait some six minutes to be fed – especially if it’s in the middle of the night! Saving time is of the essence, here.

Once you’ve heated the milk (using any of the above processes), shake the bottle gently to even out the temperature.

Do not give the bottle to the baby without first checking the temperature! Test it out by placing some drops on the top of your hand first. The milk should be lukewarm.

Take extra care when heating frozen breast milk, since too much heat can destroy the milk’s enzymes and immunizing properties.

Prepare Formula Using Warm Water

Always follow the infant formula manufacturer’s instructions when preparing a bottle of formula.

That said, most manufacturers will allow the preparation of baby formula using warm water. This means that the bottle is all set for consumption immediately after preparation.

You can either keep warm water on hand in a thermal flask, or run warm tap water directly in the bottle if you’re 100 percent sure of its safety.

If you’re not completely sure about its safety, boil the water and wait for it to cool down before using.

What to Avoid When Heating Baby Milk

Not all heating methods are safe for baby bottles.

Let’s go through the elements you need to be careful of, or downright avoid altogether.


I know, heating infant formula or breastmilk in the microwave is fast and convenient. Unfortunately, it’s not recommended at all.

As noted by the FDA, studies have shown that milk heats up unevenly in microwaves, creating ‘hot spots’ that can scald your little one’s mouth and throat.

The AAP adds that warmed breast milk changes its composition when heated too much in the microwave.

So, in short, baby bottles in the microwave = a huge no-no!

Inappropriate Storage

Throwing away milk honestly hurts so much. And this applies to both formula and breastmilk, although the latter increases the hurt element ten-fold. No one wants to throw away all that pumped milk that took so hard to express!

Sometimes, though, a stored bottle of milk has to be thrown away rather than heated.

As the FDA notes, foodborne illness is a serious health issue. Each year, 800,000 children under the age of 10 experience a foodborne illness.

Infants and young children are particularly vulnerable due to the inability of their immune system to counter foodborne bacterial infections.

With this in mind, the FDA emphasizes the following when storing milk aimed at heating:

  • Do not make more baby formula than you need. When a large quantity of formula is prepared and not handled or stored adequately, bacteria can multiply at an alarming rate.
  • Do not place an unfinished bottle back in the refrigerator. Harmful bacteria from the baby’s mouth can be transferred to the bottle and these can grow and multiply even after refrigeration and reheating.

The American Academy of Pediatrics (AAP) adds that infant formula should not be left at room temperature for more than 1 hour.

As for prepared formula that has not been given to an infant, the AAP notes it can be left in the refrigerator for 24 hours.

Using the Stovetop All the Way

Never place your baby’s bottle on the stovetop in boiling water. This can easily overheat the milk as well as melt the bottle, if it’s plastic.

Even just the thought of plastic remnants infiltrating your baby’s milk is horrible, let alone experiencing it!


It’s one scary acronym that has been getting a lot of attention lately: BPA.

This is something you’re going to want to stay on the lookout for if you’re heating baby bottles.

BPA, aka bisphenol A, is a chemical widely used in manufacturing many hard-plastic food containers.

In 2010, the FDA expressed concern about the potential effects of BPA on the brain, behavior, and prostate glands in fetuses, infants and young children.

Since then, the major bottle-making companies stopped using BPA, but there might still be a few BPA bottles doing the rounds.

When a hot or boiling element gets into contact with plastic containing BPA, traces of it get transferred on to the food. If your baby bottles are plastic, make sure they’re BPA free!

If plastic is not your thing, then you should absolutely choose glass baby bottles instead, but take good care when handling those bottles, as they can get slippery!

In Conclusion

And there you have it, that’s all you need to know to warm your baby’s bottle!

When it comes to warming baby bottles, we’re all in the same boat.

When babies get hungry, they can quickly morph into hangry creatures, and a hangry baby is no one’s idea of fun!

Kudos to you if your baby is happy with drinking a cold bottle, though. For the rest of us, preparing or heating a bottle is all about effectiveness and speed.

The methods we outlined in this article all work well and are authority-approved.

Over the course of your baby’s first months, you will very probably find yourself experimenting with all methods known to mankind, but you now know what to absolutely stay away from and what you can safely try.

Knowing that you’re providing a safe feed every single time takes the worry out of the process!

And to your baby: Bon Appetit!

Leave a Comment