Warming Breastmilk Safely

Warming pumped breastmilk isn’t the same as heating cow's milk. Heat it at too high a temperature, and you could destroy key benefits of breastmilk for baby. Here's how to safely warm up your breastmilk for your little one.

If you're pumping your breastmilk for any reason, you're likely storing some in the fridge (where it will last for 3-4 days) or in the freezer (where it will stay good for up to 6 months). And while some babies enjoy cold breastmilk, many prefer warm pumped breastmilk as it more closely matches the temperature of milk that comes straight from your body. This means that you may have to warm up your breastmilk at some point.

But heating breastmilk isn't the same as heating cow's milk. You can't just warm up breastmilk in any way you choose, because warming it up the wrong way could destroy key benefits of breastmilk for baby. Here's how to safely warm up your breastmilk for your little one.

Warming up breastmilk: Safety concerns

You'll need to warm up breastmilk safely to prevent scalding. Don't heat it up at too high a temperature! Breastmilk heated to 104 degrees Fahrenheit or hotter is unsafe for baby, as it puts them at risk for scalding.

Warming up breastmilk safely is also crucial to keeping the most beneficial parts intact for baby. Apply too hot a temperature, and you could destroy the crucial antibodies, other immune-boosting properties, and enzymes in breastmilk.

Breastmilk contains enzymes that help baby digest it, particularly important as baby's digestive system is just starting to develop. One type of enzyme, called the lipase enzyme, also helps baby process and use the fat in breastmilk. Since baby's pancreas isn't ready to produce lipase yet, baby needs the lipase to take full advantage of breastmilk's fatty acids and carbohydrates.

And breastmilk also contains immune-boosting properties that help protect baby from harmful bacteria and viruses, and support baby's still-growing immune system. In particular, the antibodies in breastmilk help your little one fight off infections.

But especially high or intense heat (over 104 degrees) can kill off these valuable antibodies, and remove the enzymes baby needs to properly process breastmilk.

This is why you should NEVER heat breastmilk directly on the stove or in the microwave. The high, intense heat of both appliances poses a risk of burning baby's mouth or lips, and rapidly destroys crucial enzymes and immune-boosting properties. Plus, the microwave unevenly distributes heat, which may create especially hot spots in the milk and further increase baby's burn risk.

Safely warming up breastmilk: The bowl of warm water method

Fortunately, using the safe methods of warming up breastmilk will keep these valuable parts of breastmilk intact and keep your little one safe.

As recommended by the Centers for Disease Control and Prevention (CDC), the best way to warm up breastmilk safely is the bowl of warm water method. Here's how to use this method:

Prepare the breastmilk: If you froze your breastmilk, you'll need to thaw it in the refrigerator first before warming it. Generally, you'll thaw it overnight. Only thaw milk that you're planning on using within 24 hours (that's 24 hours after it fully thaws).

See below if you only have frozen breastmilk and don't have time for fridge thawing.

Always plan to use the oldest breastmilk first, to continue to give baby the best quality of milk you can. Remember: "first in, first out." That means starting with the oldest milk from the fridge if you're not thawing breastmilk out, and starting with the oldest milk from the freezer if you do choose to thaw.

And no matter if your milk is frozen or refrigerated, only plan to warm milk that you think your baby will drink within 2 hours of warming. If you need to re-portion a container of breastmilk for warming, do so with clean hands, then place the containers back in the fridge.

Prepare warm water. You can heat up water on the stove or in the microwave, then pour it into a bowl. Or, you can run warm water right from the tap into a bowl. Make sure the water is very warm, but not boiling.

Let the water sit: Wait until the water reaches body temperature (about 98-99 degrees Fahrenheit, if you're checking with a thermometer) before moving on.

Add a container of breastmilk: Once the water is at the right temperature, you can put a sealed bottle of breastmilk (with no nipple), or a tightly sealed breastmilk bag, in the bowl. Keep the breastmilk container in the water for about 2 minutes, or until it reaches body temperature (98-99 degrees Fahrenheit).

Need warmed milk right away, and have no time for fridge thawing? You can thaw and warm breastmilk in the water bowl, but it'll take 10-15 minutes or more to complete the process. You might also need to prepare another bowl of warm water if the first one gets too cold.

Prepare the milk for baby: Wash your hands thoroughly, then pour breastmilk in a bottle (if it isn't already in the bottle) and add the bottle nipple. If it looks like the fats have separated from the rest of the breastmilk, swirl the breastmilk for a bit to re-incorporate the fats. You can also shake the bottle if desired, as shaking won’t damage the nutrients in the breastmilk.

Test the temperature: Always shake a few drops of breastmilk on your wrist before feeding baby, to make sure it isn't too hot or cold.

Use within 2 hours: Warmed, pumped breastmilk must be used within 2 hours. If there's any left after warming the milk and feeding baby, and 2 hours have passed since the first feeding, you'll unfortunately need to throw that milk out. It's also unsafe to refreeze thawed breastmilk.

Safely warming up breastmilk: Two other methods

There are two other safe ways to warm up breastmilk.

The tap method: If you choose this method, turn on the tap and run warm water. Then, place a sealed bag or bottle of breastmilk under the running water until it reaches the desired temperature. Although this is on the list of safe methods recommended by the CDC, it's not as efficient as the bowl of warm water method. It wastes a lot of water, and takes longer than the bowl of warm water method.

The bottle warmer: Bottle warmers offer an easy way to warm breastmilk, as long as you use them correctly. But if you don't follow the exact instructions, there's a risk that you'll overheat breastmilk with a bottle warmer and destroy the valuable nutrients. Also, it isn't necessary to spend your money on a bottle warmer because other safer options are available that use materials you already have. It's up to you whether you want to invest in a bottle warmer.

Like with the bowl of warm water method, you'll need to swirl or shake breastmilk to mix in the fats, and test the temperature before feeding baby, if you use a tap or bottle warmer. Also, you only have 2 hours to use the breastmilk after warming when using either of these methods.

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