19 Breast Milk Storage: Everything You Should Know
Storing breast milk can feel like a big task, but it’s super important, especially if you’re heading back to work or need to be away from your baby for a while. Knowing how to store your milk properly helps keep it fresh and nutritious, so your baby gets all the good stuff, even when you’re not around. Whether you’re just starting to pump or looking for a refresher, this guide will help you feel confident about storing breast milk the right way.
Why Proper Storage Matters
Breast milk provides babies with essential nutrients, antibodies, and other beneficial compounds that are vital for their growth and development. Storing breast milk improperly can compromise its safety and quality. Bacteria can multiply if milk is stored at incorrect temperatures, potentially causing illness. Additionally, improper storage can lead to the loss of valuable nutrients, especially vitamins like vitamin C, which degrade over time.
Safe storage of breast milk involves understanding the key aspects: what type of containers to use, where to store the milk, and how long milk can remain viable before it needs to be used or discarded.
Prepare to Pump and Store Milk
Before pumping, ensure that all equipment is sanitized. Hand hygiene is crucial — wash hands thoroughly with soap and water to minimize the risk of contamination. If soap and water aren’t available, an alcohol-based hand sanitizer can be used as an alternative. The cleanliness of bottles, storage bags, and other pumping equipment is just as important. Cleaning pumps, storage containers, and accessories after each use is crucial to prevent bacterial growth.
A breast milk pump or a breast pump can aid in the collection of milk, and it’s important to choose a device that suits your needs. Manual pumps can be more affordable but may take more effort, while electric breast pumps tend to offer quicker milk expression, particularly for mothers who need to pump regularly.
Choose Containers for Storing Breast Milk
The right containers for storing breast milk is essential for preserving the milk’s quality. Only use containers made specifically for storing breast milk, such as BPA-free plastic bottles, glass containers, or special milk storage bags. These containers are designed to withstand freezing and ensure the milk does not come into contact with harmful chemicals.
Avoid using disposable bottle liners or general household plastic bags for storage, as these are not designed for food safety and may contain harmful chemicals that could leach into the milk.
Ideal Storage Conditions for Breast Milk
Breast milk can be stored in several places: at room temperature, in the refrigerator, or in the freezer. Each storage method has its own timeframe for how long milk can safely remain viable.
Room Temperature Storage
Freshly expressed breast milk can safely remain at room temperature (up to 77°F or 25°C) for up to four hours. After four hours, the milk should either be used or refrigerated. While it’s safe to store milk at room temperature, it’s best to use or refrigerate milk as soon as possible to reduce the risk of bacterial growth. If your baby does not consume the milk, discard any leftovers after an hour of feeding.
Refrigerator Storage
Fresh milk stored in the refrigerator at a consistent temperature of 40°F (4°C) is safe for up to four days. For mothers who are storing milk for later use, a clean, labeled container should be placed at the back of the refrigerator where temperatures are most stable. Milk stored on the door may be subject to temperature fluctuations, making it less ideal for longer storage.
In cases where the milk will not be used within four days, freezing is the best option.
Freezing Breast Milk
Freezing allows mothers to store breast milk for extended periods. The optimal freezing temperature for breast milk is 0°F (-18°C) or lower. When milk is frozen immediately after pumping, it can last up to six months, although up to 12 months is generally acceptable, though the quality may degrade over time.
When freezing, it’s important not to overfill storage bags or containers, as milk expands as it freezes. Leave about one inch of space at the top of each container to allow for this expansion. For best results, label each container with the date it was expressed. Storing milk in smaller portions, such as 2 to 4 ounces (60 to 120 milliliters), is ideal for reducing waste and ensuring only the amount needed for each feeding is thawed.
Use Coolers and Ice Packs
If you need to transport breast milk, an insulated cooler with ice packs can keep it at the proper temperature for up to 24 hours. After 24 hours, milk should be refrigerated or frozen to maintain its safety and nutritional quality.
Thaw and Warm Breast Milk
Proper thawing and warming of breast milk is as important as the storage process. When thawing frozen breast milk, thaw the oldest milk first to prevent milk from remaining in storage too long. It is best to thaw frozen breast milk in the refrigerator overnight. This slow thawing process helps maintain the milk’s nutrients and quality.
If you need to thaw milk more quickly, place the container in warm water or hold it under running warm water. However, never use a microwave to thaw or heat breast milk, as microwaving can create hot spots that may burn your baby’s mouth and degrade the milk’s nutritional content.
Once milk has been thawed or warmed, it should be used within two hours and should not be refrozen. After feeding, any leftover milk should be discarded to prevent bacterial contamination.
Signs of Spoiled Breast Milk
If the milk smells sour or has a curdled texture, it may have gone bad and should not be fed to the baby. Some variation in smell, taste, and color can occur with freshly expressed and thawed milk, depending on diet and storage methods, but milk that smells rancid or off should be discarded.
Tips for Maximizing Storage Efficiency
● Label and Date. Label each storage container with the date and time the milk was expressed. This ensures that the oldest milk is used first and that you’re aware of when it was pumped.
● Freeze in Small Quantities. Store milk in smaller portions to avoid thawing more than what your baby needs. This reduces waste and allows for easier portion control when you need to thaw milk quickly.
● Avoid Overfilling Containers. As milk expands when frozen, leaving space at the top of containers helps prevent spills and ensures the milk remains sealed and fresh.
● Storage Location Matters. For optimal freezing, place milk at the back of the freezer, where the temperature remains constant. Avoid placing it on the freezer door, as this can cause fluctuations in temperature.
● Storage Bags vs. Bottles. While both breast milk storage bags and BPA-free bottles work well, bags may take up less space, making them ideal for freezing.
The Bottom Line
Storing breast milk doesn’t have to be stressful. By following a few simple steps—like using the right containers, keeping milk at the right temperature, and labeling everything—you can make sure your baby gets fresh, nutritious milk every time. With a little planning, you’ll be all set to keep your breastfeeding routine going strong, even when you’re not always there.
FAQs
Can You Add Fresh Milk to Already Stored Milk?
Yes, freshly expressed breast milk can be added to milk already in the refrigerator or freezer, but only after it has cooled to the same temperature. Never add warm milk directly to frozen milk, as this can cause the frozen milk to thaw and compromise its safety.
How Long Can You Store Thawed Milk?
Once breast milk has been thawed in the refrigerator, it should be used within 24 hours. Milk that has been thawed but not used should never be refrozen.
Can You Reheat Milk More Than Once?
It’s not advisable to reheat breast milk more than once. Each reheating and cooling cycle increases the potential for bacterial growth and nutrient loss.
How long can breast milk stay at room temperature?
Breast milk can safely stay at room temperature (up to 77°F or 25°C) for up to 4 hours. After this time, it should be used or refrigerated.
How long can I store breast milk in the fridge?
Freshly expressed breast milk can be stored in the fridge at 40°F (4°C) for up to 4 days.
How long can I store breast milk in the freezer?
Breast milk can be stored in the freezer at 0°F (-18°C) for up to 6 months, though it is acceptable to store it for up to 12 months.
Can I combine milk from different pumping sessions?
Yes, but only if the milk has been cooled to the same temperature. Freshly expressed milk should not be added to already frozen milk.
How should I thaw frozen breast milk?
Thaw frozen breast milk in the refrigerator overnight or by placing the container in warm water. Avoid using a microwave to thaw milk.
How do I warm breast milk?
Warm breast milk by placing it in a container of warm water or holding the bottle under running warm water. Never microwave breast milk.
Can I refreeze breast milk once it has been thawed?
No, once breast milk has been thawed, it should not be refrozen.
Can I store breast milk in regular plastic containers or bags?
No, only use BPA-free plastic bottles, glass containers, or specially designed breast milk storage bags to store breast milk.
Can I use milk that was left out too long?
If breast milk has been left out for more than 4 hours, it should be discarded.
How long can I keep thawed breast milk at room temperature?
Thawed breast milk should be used within 1 to 2 hours if kept at room temperature.
How should I store breast milk if my baby is in the hospital?
Consult with hospital staff for specific storage instructions, especially for premature or ill babies, as there may be different guidelines.
Is breast milk safe to use after it separates?
Yes, breast milk may separate into fat and liquid. Gently swirl the milk to recombine it, but avoid shaking the bottle.
How should I clean my breast pump parts?
Clean all pump parts and bottles thoroughly after each use with warm, soapy water. Sterilize them regularly, especially for newborns or premature babies.
Can I store milk in a cooler with ice packs?
Yes, breast milk can be stored in an insulated cooler with ice packs for up to 24 hours. After 24 hours, it should be refrigerated or frozen.