How To Warm Breast Milk Safely

How To Warm Breast Milk Safely

The many health benefits of breast milk for babies are well documented because it is a precious source of nourishment for infants. Breast milk also provides babies with essential nutrients and antibodies that promote healthy growth and development.

If you choose to warm your breastmilk it is important to gently heat the milk to preserve its nutrients and prevent burns or nasty hot spots. There are a few different ways to warm breast milk, but the most important thing is to use a method that is gentle and even.

In this guide, we will explore the many different techniques for safely thawing and warming breast milk, from gradual room temperature methods, warm water baths to baby bottle warmers. 

By following these guidelines, you will be able to confidently provide your baby with the best possible nourishment while ensuring their safety.

Why Safely Warming Breast Milk Matters

To improve the taste of breast milk for your baby, it's vital to warm it gently to a lukewarm temperature. This careful warming process will render the breast milk more appealing to your little one.

Breast milk is abundant in vital nutrients essential for your baby's growth and development. However, subjecting breast milk to rapid or uneven heating can jeopardise these crucial nutrients.

Excessive heating of breast milk can reduce its nutritional benefits for your baby and may potentially cause discomfort and reluctance to drink it by harming your baby's delicate mouth and throat.


The Basics of Storing Breast Milk

Before we delve into the intricacies of warming breast milk, it's essential to understand how to store it correctly.

Proper storage ensures your breast milk maintains its nutritional value and remains safe for your baby. Bacteria can grow in breast milk that is not stored or handled properly.

Proper Storage Containers

First, use clean, BPA-free containers specifically designed for breast milk storage. These containers can be made of glass or plastic, but they must be food-grade and have tight-fitting lids to prevent leaks and contamination.

Labeling & Dating

Label each container with the date. It helps you use the oldest milk first, reducing waste and ensuring freshness. Include the time if you are collecting milk throughout the day.

Freezing vs. Refrigeration

If you don't plan to use your expressed milk within a few days, consider freezing it. Freezing preserves the milk's nutritional value for an extended period. Use freezer-safe bags or containers and remember to remove as much air as possible to prevent freezer burn.

Recommended storage times

Breast milk can be stored safely at different temperatures:

  • Room temperature (77°F or 25°C) for up to 4 hours.
  • Refrigerator (32-39°F or 0-4°C) for up to 4 days.
  • Freezer (0°F or -18°C or lower) for up to 12 months.

You should always store breast milk at the back of the fridge or freezer to maintain a consistent temperature.

What are the Different Ways to Warm Breast Milk?

There are a few different ways to warm breast milk, including:

Bowl of Warm Water

This is a simple and effective way to warm breast milk.

Place the bottle of breast milk in a bowl of warm water (not hot). You need to ensure to stir the milk occasionally. This method can take 5-15 minutes. It also depends on the temperature of the water and the size of the bottle or bag.

Running Warm Water

If you're short on time, try holding the bottle or bag under warm water.

Be sure to rotate the bottle or bag so that it heats evenly. This method can take anywhere from 1-3 minutes, depending on the temperature of the water and the size of the bottle or bag.

Bottle Warmer

There are a variety of Baby Bottle Warmers on the market that can be used to warm breast milk.

Bottle warmers typically heat breast milk more evenly and consistently than other methods. However, it is important to follow the manufacturer's instructions. It will help you to avoid overheating the breast milk.

Tips For Warming Breast Milk Safely

Here are some tips for warming breast milk safely:

  • Do not microwave breast milk: because it can create hot spots. These hot spots can burn a baby's mouth and throat. Additionally, microwaving can destroy the nutrients in breast milk.
  • Do not boil breast milk: as this can destroy the essential nutrients in it.
  • Do test the temperature of the breast milk before feeding it to your baby: by placing a few drops of milk on the back of your wrist. The milk should feel lukewarm but not hot.
  • Do not reheat breast milk that has already been warmed: as this can lead to the growth and development of bacteria.

    How to Warm Breast Milk When You're On The Go?

    If you need to warm breast milk when you're on the go, there are a few things you can do:

    Room Temperature Thawing

    Thawing breast milk at room temperature is a safe and gradual method but it can take some time.It is essential to plan to ensure you have enough time for the thawing process.

    Begin by transferring the frozen breast milk container from the freezer to the refrigerator the night before you intend to use it. This slow thawing process helps preserve the milk's safety and quality by avoiding rapid temperature changes.

    Once the milk has completely thawed in the refrigerator, it should be at a lukewarm temperature, ready for feeding your baby.

    Warm Water Bath

    Creating a warm water bath is another gentle and effective way to warm frozen breast milk.

    To do this, fill a container with water at approximately 98.6°F (37°C) or slightly warmer. Ensure the breast milk container is sealed to prevent water from getting in.

    Submerge the sealed container in warm water, ensuring it's fully covered and periodically swirl the container to promote even heating. To check the milk's temperature, you can test a few drops on your wrist.

    When it feels lukewarm, it's suitable for feeding.

    Baby Bottle Warmer

    Investing in a Portable baby Bottle Warmer can streamline the thawing and warming process for breast milk.

    A Portable baby Bottle Warmer offers a convenient and invaluable solution for parents on the go. These versatile devices ensure that your baby’s breast milk can be gently warmed anytime, anywhere, preserving crucial nutrients in the process.


    With the ability to provide a consistent and safe heating process, portable bottle warmers not only guarantee that your breast milk remains palatable and at an ideal temperature, but also prevent overheating that might destroy nutritional value.

    Look for a baby bottle small enough to fit into your baby bag, with pre-set temperatures, and one that provides USB charging so you can power it up from wherever you are when you most need it. Always make sure you follow the manufacturer's instructions for your specific bottle warmer.

    As with other warming methods, you can test the milk's temperature by placing a few drops on your wrist and it should be lukewarm before feeding your baby.

    Microwave Precautions

    While using a microwave to warm breast milk is an option, it requires extra caution to avoid damaging the milk or creating hot spots that could harm your baby. We wanted to cover off this method of warming breast milk without our guide but it is not one we advise.

    If you do decide to use a Microwave to warm your baby’s breast milk, ensure the container you use is microwave-safe and has a secure lid to prevent spills.

    Opt for the lowest power setting or use the defrost function on your microwave. Heat the milk in short increments, such as 20-30 seconds. After each cycle, stir the milk thoroughly to distribute the heat evenly.

    Finally, test the milk's temperature by placing a few drops on your wrist to ensure it's lukewarm before feeding your baby. It's crucial to avoid reheating or reusing breast milk that has been microwaved, as this can compromise its quality.

    Body Heat Method

    Did you know you can use your body heat to warm your baby’s breast milk?

    This may sound absolutely bonkers crazy, but if you find yourself in a situation without access to warm water or a bottle warmer you can warm breast milk with your body heat.

    All you need to do is place the bottle or bag of breast milk in your pocket or between your breasts (if you have been blessed with big enough boobies!).


    This method will take longer to warm the milk, but it is a convenient option when you're on the go although it can be slightly uncomfortable in the winter months.

    Additional Tips For Warming Breast Milk Safely

    • It is advised to put frozen breast milk in the refrigerator overnight before warming it. It will help preserve the nutrients in the milk.
    • If you need to unfreeze the frozen breast milk quickly, you can place the bag of milk in a bowl of warm water. Be sure to stir the milk occasionally, and do not let it sit in the water for more than 30 minutes.
    • Do not warm breast milk in a saucepan. It can overheat the milk and destroy the nutrients in it.


    Thawing and warming breast milk is a crucial element of infant care, necessitating a delicate balance between safety and quality. It’s important to understand the risks to your baby when storing and using breast milk.

    Safely and gently warming breast milk is paramount for preserving its essential nutrients while preventing any risk of burns. While there are various methods available for warming breast milk, the key lies in choosing a gentle and uniform approach.

    By conscientiously avoiding excessive heating or reheating, you can ensure that your baby not only receives safe breast milk but also benefits from its valuable nutrients and antibodies.

    Read more about The Best Ways To Warm a Baby's Bottle and if you find yourself uncertain about the safest warming method, don't hesitate to seek guidance from your GP or midwife.