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Can You Reheat Breast Milk? Everything You Need to Know

Even if you want to breastfeed your baby, chances are there will be times you need to store pumped or expressed milk in the refrigerator or freezer to use later. So the question is: Can you reheat breast milk?

The answer is yes, you can!

In this article, we'll talk about everything you need to know about reheating breast milk, from the best reheating methods to certain precautions and tips.

Why Reheat Breast Milk?

There are several reasons why you might need to reheat pumped or expressed breast milk for your baby. While it’s safe to serve cold or at room temperature, there may be certain situations where you may want to warm it up.

To Make It More Like You

Reheating breast milk to your body temperature can make it feel more like it comes directly from you. Cold breast milk can be less appealing to babies because it doesn’t  provide the warmth and comfort they get from you.

To Improve Taste and Consistency

Although cold milk is safe, some babies prefer the taste of warmed breast milk. Reheating breast milk can enhance its flavor, making it more appealing to your baby's taste buds. Additionally, reheating can help redistribute the cream that may have separated, resulting in a more consistent texture.

Best Ways to Warm Breast Milk

When it comes to reheating breast milk, there are two methods that help preserve its nutritional value and make sure it’s safe for your baby to consume. Let's explore these below!

Using a Warm Water Bath

  1. Fill a container or bowl with warm water. Select a clean container or bowl that is large enough to hold the bottle or bag of breast milk bottle. Fill the container or bowl with warm water. Avoid using hot or microwaved water because excessive heat can damage the breast milk's nutrients.

  2. Place the closed or sealed breast milk bottle or bag into the warm water bath. Make sure the water level is below the lid or top of the container to prevent any water from getting into the breast milk.

  3. Let the bottle or bag sit for 10 to 15 minutes. Allow the breast milk to warm up gradually in the warm water bath. Swirl the bottle or bag occasionally to promote even heating and mix in the fat. This also helps to prevent hot spots and ensures that the milk warms up uniformly.

  4. Check the temperature. After a few minutes, remove the container from the water bath and carefully test the temperature of the breast milk by dripping a few drops onto the inside of your wrist. It should feel slightly warm, or you should feel nothing at all. This method lets you gauge the temperature without risking burns to your baby's mouth.

Using a Bottle Warmer

  1. Read the instructions. Before using a bottle warmer, carefully read the manufacturer's instructions and familiarize yourself with the device's specific guidelines and settings.

  2. Prepare the bottle warmer. Place the bottle warmer on a flat, stable surface and ensure it is plugged into a power source. Add water to the bottle warmer as per the instructions, if required. Some bottle warmers may not require water.

  3. Set the desired temperature. Depending on the model, adjust the temperature setting on the bottle warmer to the desired level. Most bottle warmers have adjustable settings to accommodate different milk temperatures.

  4. Place the bottle inside. Gently place the bottle of breast milk into the bottle warmer. Ensure that the bottle is properly sealed to prevent any milk leakage or water entering the bottle.

  5. Turn on the bottle warmer. Follow the manufacturer's instructions. The device will begin heating the breast milk to the set temperature.

  6. Monitor the warming process. Keep an eye on the warmer as the breast milk warms up. Some warmers have timers or automatic shut-off features that indicate when the milk is ready.

  7. Test the temperature. Once the warming process is complete, remove the bottle from the warmer and carefully test the temperature of the breast milk. Drip a few drops on the inside of your wrist to make sure it’s comfortably warm, not hot. The perfect temperature is one where you feel nothing at all.

Thawing Frozen Breast Milk

While the methods above are great for warming cool or room temperature breast milk up, they're not the best for frozen milk. Follow these steps to reheat frozen milk:

  1. Retrieve the frozen breast milk. Remove the frozen breast milk storage bag from the freezer. Make sure it has been properly labeled with the date of expression and still safe to consume. (Frozen milk can be stored for 3 to 6 months in the freezer or 6 to 12 months in a deep freezer.)

  2. Thaw in the refrigerator. Place the frozen breast milk bag in the refrigerator. This will help preserve its quality and minimize the risk of bacterial growth. Depending on the volume of milk and the temperature of your refrigerator, thawing may take approximately 12 to 24 hours. You may want to put it in the refrigerator overnight to use the next day.

  3. Use a warm water bath for quicker thawing (OPTIONAL). If you need to thaw breast milk more quickly, you can use the warm water bath method as described above. Swirl the container periodically to speed up the thawing. Do not use hot water or a microwave as they can damage the breast milk's nutritional quality and create hot spots that can burn your baby’s mouth.

  4. Check the temperature. Once the breast milk is thawed, gently swirl the container to mix in the fat that may have separated. Open the container or bag and carefully check the temperature of the breast milk by dripping a few drops on the inside of your wrist. It should be comfortably warm, but not hot.

Once the breast milk has reached the desired temperature, it is ready to be fed to your baby. Pour the warmed breast milk into a sterilized bottle or use the appropriate feeding method for your baby.

Precautions When Reheating Breast Milk

When reheating breast milk, it's important to follow some precautionary tips to ensure the safety and quality of the milk you give your baby. Here are some important ones to keep in mind:

  1. Avoid repeated reheating and cooling. It's recommended that you only heat breast milk once. Repeated reheating and cooling leftover milk can lead to nutrient loss and increase the risk of bacterial growth. To minimize waster, only heat the amount of milk needed for each feeding.

  2. Discard unused leftover breast milk. Unused breast milk that has been warmed should not be put back into the refrigerator or freezer or stored again for later use. Bacteria can multiply quickly in human milk that has been heated and left at room temperature. It's important to discard any leftover milk that your baby does not consume within one to two hours to prevent contamination.

  3. Never refreeze human milk once it's been thawed. Thawed milk must be used within 24 hours and should be stored in the refrigerator until it is ready to be used.

  4. Use airtight containers. When storing and reheating freshly expressed breast milk, use clean, airtight containers specifically designed for that purpose. These containers help prevent contamination and maintain the quality of the pumped milk. Remember that liquid expands when it freezes, so leave some extra space in storage bags/bottles.

  5. Recognize signs of spoilage or contamination. Before reheating breast milk, carefully examine it for any signs of spoilage or contamination. If the milk smells sour, looks clumpy, or has an off color, it may be spoiled and should not be fed to your baby. Additionally, if the breast milk has been left at room temperature for more than two hours, it's best to discard it and not take a chance.

  6. Practice good hygiene. Always wash your hands thoroughly before handling breast milk or any feeding equipment. Clean all bottles, nipples, and breast milk storage containers with warm soapy water and rinse them well before use.

  7. Label and date the breast milk. Properly label each container or bag of breast milk with the date of expression before storing it. Then store it with the newest milk in the back and oldest milk in the front of the refrigerator or freezer. This helps you keep track of the storage time and ensures that older breast milk is used first.

Frequently Asked Questions

Is it okay to reheat breast milk twice?

It's not recommended to reheat breast milk multiple times as it can lead to nutrient loss and increase the risk of bacterial growth. It's best to heat only the amount needed for each feeding to minimize waste and discard what you don't use.

Can you reheat breast milk after feeding?

It's not recommended to reheat breast milk after it has been fed to your baby. Once breast milk has been warmed or thawed, it should be discarded after one to two hours to prevent bacterial contamination.

How many times can I reheat breast milk?

Breast milk should be reheated only once. Repeatedly reheating breast milk can result in nutrient degradation and increase the risk of bacterial contamination. It's best to heat only the required amount for each feeding and discard any remaining milk.

Can you reheat pumped breast milk once it has cooled?

Yes, you can reheat pumped breast milk after it has been cooled. However, it is important to handle and store cooled breast milk properly to maintain its quality and safety. Cooled, freshly pumped breast milk should be refrigerated promptly and reheated using appropriate methods, such as a warm water bath or bottle warmer.

What is the fastest way to warm breast milk?

A quick way to warm a bottle of cold breast milk Is to place it in a bath of warm water or run it under a stream of warm water in the sink.


Done right, reheating breast milk will retain much of its nutritional value, taste good to your baby and not risk contamination. By following the steps and tips outlined above, you'll be able to safely and effectively do just that!

Reviewed by Linda Dahl, MD


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