Expressing and storing breast milk is a great way to ensure your baby always has a steady supply of nutrition, even when you can’t be there to personally breastfeed. Packed with essential antibodies, proteins, vitamins and minerals, having a reserve of breast milk means your little one can reap all the amazing benefits with every feeding. 

Experts recommend keeping at least 2 to 4 ounces of expressed breast milk for future use, the average amount of milk consumed in one sitting. You might find yourself with a bit more of that precious ‘liquid gold’ than expected — but still, this doesn’t mean it comes easily! Read on to find out how to preserve the precious surplus safely and correctly to honour your efforts and maintain your baby’s health.

Guidelines for Storing Breast Milk

Pumping and storing breast milk is a delicate process that requires strict control over hygiene, temperature and duration. Keep in mind these general storage recommendations that help ensure your milk stays safe and nourishing for your baby:

• Cleanliness and Hygiene: Always wash your hands thoroughly with soap and water before expressing or handling breast milk. If using a manual or electric pump, make sure all parts of the pump are clean and dry, especially the tubing, which can be prone to mould if moisture is trapped.
• Temperature Requirements: Temperature changes can affect the nutritional value, flavour and consistency of the breast milk. If breast milk is left out or stored improperly, it can also lead to spoilage and become harmful to the baby. 
• Duration of Storage: You can prolong the shelf life of breast milk if it is kept under appropriate conditions, but it cannot last forever. It is important to observe the duration so your baby receives milk that is safe, fresh and nutritious.

Storing and Freezing Breast Milk

When it comes to quality, freshly expressed breast milk is definitely the gold standard — but refrigerated and frozen breast milk are excellent alternatives when fresh milk isn’t an option.

• Storage Solutions: Store breast milk in storage bags and containers specifically designed for keeping breast milk. They should be BPA-free and made from either glass or plastic. Make sure the containers have a tight-fitting lid (airtight) and are thoroughly sterilised before use.
• Location and Temperature: The ideal location to store breast milk is towards the back of the fridge, where the temperature is cold and consistent (4°C). Avoid storing it at the door where temperatures are susceptible to fluctuating. You can also keep breast milk in the freezer (-18°C), provided the storage solution is freezer-proof.
• Recommended Storage Time: While fresh breast milk must be consumed within 4 hours at room temperature, it can last up to 4 days in the refrigerator if stored properly. When frozen, breast milk can maintain optimal quality for up to 6 months.

Defrosting and Thawing Breast Milk

You should defrost or thaw breast milk that has been frozen or refrigerated before serving it to your baby. Storing your breast milk in smaller portions can speed up this process. If you need a larger amount, consider combining multiple smaller portions together as needed.

• First in, First Out (FIFO): The first breast milk expressed should be the first one used. Always use older breast milk first, as it can degrade in quality over time. 
• Thawing/Defrosting Methods: You can defrost frozen breast milk overnight by moving it to the refrigerator section the night before. For quicker thawing, run the bottle under or soak it in a bowl of warm water. Avoid thawing breast milk at room temperature.
• Timing Your Usage: You will need approximately 12 hours to defrost breast milk in the fridge. According to the CDC, this milk should be used within 24 hours from the time of thawing. Additionally, thawed breast milk that has been brought to room temperature must be consumed or discarded within 2 hours.

Preparing and Feeding Breast Milk

While warming chilled breast milk to a comfortable temperature isn’t strictly necessary, many parents prefer to do so. Below are some suggestions for serving breast milk, whether it is cold, lukewarm or warm.

• Warming the Milk: Heating up the milk slightly can make it more palatable for your baby. You can do this by placing the bottle in a container of warm water, raising it to body temperature, below 40°C. For more precision, you can invest in a bottle warmer for even and safe heating.
• Always Test First: To prevent scalding your baby, apply a few drops of the prepared breast milk on your wrist to test the temperature before feeding. Your milk can be warm but it should not be hot to the touch.
• Gently Swirl: Lastly, gently swirling the bottle can improve your baby’s feeding experience. This simple action helps mix the breast milk and combine any separated fat for a smoother, more consistent taste and texture. Just be careful not to shake the bottle as it can introduce air bubbles, which can potentially lead to trapped wind.

Some Additional Precautions

These tips can help both new and seasoned parents follow best practices for storing and using expressed breast milk.

• Don’t Mix Warm and Cold: Don’t add body temperature milk to already cooled milk, as this can raise the temperature and affect its quality. Only small amounts of already chilled milk can be added to properly stored, preexisting milk in containers.
• Freeze or Chill Promptly: Be sure to freeze or chill the milk as soon as possible after expressing to maintain its freshness. Storing it directly helps guarantee its safety and quality.
• Use Tight-Fitting Lids: Containers with tight-fitting lids contribute to the prevention of freezer burn, which occurs when breast milk is exposed to cold and dry freezer air. While it isn’t harmful, freezer burn can develop an unpleasant taste that may make your baby more likely to reject the milk. Milk storage bags also come with airtight seals to prevent freezer burn.
• Leave Space for Expansion: Always leave about one inch of space at the top of containers or bags, as milk tends to expand in the freezer. This circumvents spillage and breakage.
• Never Boil Breast Milk: Heating breast milk above 40°C may cause it to lose its antibodies and nutrients.

Frequently Asked Questions About Expressed Breast Milk 

Explore answers to common questions about expressed breast milk.

What is the substance that has formed on top of my stored breast milk?

The creamy layer on the surface of your breast milk is fat that has separated and risen to the top. This is completely normal and can be easily resolved by gently swirling the bottle to mix it back together.

Can I heat up breast milk in a microwave?

Breast milk should never be prepared in a microwave, whether it is for defrosting, thawing or warming. Microwaving can create hot spots in the milk that are difficult to detect until it burns your baby’s mouth. Plus, overheating milk can destroy its bioactive proteins and reduce its fat contents.

Can I defrost and freeze breast milk again?

It is not recommended to refreeze breast milk that has already been thawed. If you need to use only part of a thawed portion, you can do so, but any remaining milk should be discarded after the 24-hour period, inclusive of the time used for thawing.

How do I know if breast milk is spoiled? 

You can tell if breast milk is spoiled by checking for an odd smell or off-taste. It is often described as sour, fishy and rancid. Fresh breast milk should be slightly sweet, creamy and sometimes soapy. 

What items do I need for storing breast milk?

To store breast milk safely, consider investing in specialised breast milk storage bags and containers for safe and leak-proof storage, bottle warmers for warming milk without compromising quality, and cooler bags for transporting milk safely on the go. You should also check if your freezer and refrigerator are working properly. While not for storage, electric breast pumps can make expressing milk less demanding and more convenient, helping parents better manage their milk supply and feeding schedules.

Visit Mothercare Malaysia to browse our online catalogue and streamline your breastfeeding experience today. Alternatively, find us at our experience stores at Suria KLCC and Mid Valley Megamall for expert, on-site assistance.