Can warmed breast milk be refrigerated again? This question is asked by many new parents. They don’t know how much amount should be fed to their babies and probably warm up much more breast milk than their babies need.
If you still don’t know, check our post on baby feeding charts and schedules by age.
Knowing the amount of breast milk for different ages is the first step. As parents, we also have to know much more than we’re prepared.
In this comprehensive guide, we’ll not only answer the above question – can warmed breast milk be refrigerated again, but also the science behind breast milk storage, the reasons why you shouldn’t re-refrigerate warmed milk, and practical tips for managing and warming breast milk to ensure the best care for your baby.
What is Breast Milk?
We all know that breast milk is the most important source of nutrition for infants, especially for newborns. Breast milk includes microbiomes and miRNAs for growth, development, and immunity and is an irreplaceable source of nutrition for babies.
Even though formulas may have many similarities to breast milk in many components, there is no perfect substitute for breast milk.
According to the studies, breast milk contains about 87%–88% water, and 124- g/L of solid components as macronutrients, including about 7% (60–70 g/L) carbohydrates, 1% (8–10 g/L) protein, and 3.8% (35–40 g/L) fat.
The composition may vary depending on the environmental factors. What moms eat during breastfeeding may also affect the actual composition of their breast milk.
That’s why we recommend moms stay hydrated and eat nutritious foods for power pumping. The more nutrition you take in, the more healthy breast milk you’ll feed to your baby.
How Important Breast Milk Is
As an irreplaceable part of your baby’s diet, breast milk certainly plays an important role in their lives, mainly including these areas:
1. Nutritional Benefits: Breast milk is the most nutritionally complete food for babies, especially newborns. It provides all the essential nutrients, including proteins, fats, and carbohydrates, that are needed for optimal growth and development.
2. Immune System Support: Breast milk has large amounts of microRNAs, which can be absorbed by intestinal epithelial cells to play an important role in a baby’s immunoprotection and developmental programming. This natural defense system is especially vital in the early months when the baby’s own immune system is still developing.
3. Emotional Bonding: Breastfeeding fosters a strong emotional bond between mother and baby. The physical closeness and skin-to-skin contact during breastfeeding promote a sense of security and attachment, which is beneficial for the baby’s emotional development.
4. Reduced Risk of Health Issues: Breast milk contains rich and diverse microbial communities, including the genera Staphylococcus and Streptococcus. They work as various bioactive proteins and peptides on the intestinal tract, vasculature, nervous system, and endocrine system, ensuring your baby grows healthy and well.
5. Cost-Effective: Breastfeeding is also economically beneficial. Feeding your baby with formulas can be expensive. So it’s best for moms to breastfeed their babies.
Reasons Why Warmed Breast Milk Should Not Be Refrigerated Again
According to health organizations and experts, including the American Academy of Pediatrics (AAP) and the Centers for Disease Control and Prevention (CDC), warmed breast milk should be used within a specific timeframe (generally within 1-2 hours) and should not be re-refrigerated.
Warmed breast milk should NOT be refrigerated again for several reasons. Here are some important ones we think you should not put the warmed breast milk being refrigerated again.
1. Bacterial Growth: Once breast milk has been warmed, it becomes a more favorable environment for bacterial growth. Bacteria can multiply rapidly at warmer temperatures, increasing the risk of contamination. Even if the milk is returned to the refrigerator, it does not stop bacterial growth that may have begun during the warming process.
2. Nutrient Degradation: Repeated warming and cooling can degrade the nutritional quality of breast milk. Heat can destroy some of the vital nutrients and enzymes that are crucial for the baby’s health. This degradation can reduce the effectiveness of breast milk in providing the necessary nourishment and immune protection.
3. Risk of Spoilage: Warmed milk is more susceptible to spoilage. If breast milk has been left out for too long or warmed more than once, it may spoil and become unsafe for consumption. Spoiled milk can cause gastrointestinal upset and other health issues in infants.
That’s why the storage bags and bottles are launched to help store breast milk safely in the refrigerator and freezer. Read our post on how to pump and store your breast milk.
How to Deal with Leftover Warmed Breast Milk
The CDC recommends using the leftover breast milk within 2 hours after warming up. If the warmed breast milk is put on the countertop at room temperature for over 2 hours, the leftover breast milk should be thrown away. That’s why you should cleverly store, thaw, and warm the breast milk in small amounts.
So here are some tips to deal with leftover warmed breast milk.
1. Disposal: Just as the CDC’s suggestion, the safest practice is to discard any leftover breast milk that has been warmed if your baby does not eat within 2 hours. This prevents the risk of bacterial growth and contamination. It’s important to follow this guideline to protect your baby’s health avoiding eating bad milk.
2. Pre-Warming Preparation: Every drop of breast milk is precious. To avoid wastage, pre-warm only the amount of milk you expect your baby to consume. Follow the tips in our post on breast milk feeding amount by age to prepare the approximate amount for your baby. This helps minimize the amount of milk left over and ensures that the milk remains fresh and safe for feeding.
3. Managing Multiple Feedings: Based on your baby’s needed amount for their current age, you anticipate needing more milk for multiple feedings, and consider warming small amounts at a time. For instance, you can warm a portion of milk and refrigerate the rest, warming additional portions as needed.
4. Using Breast Milk Wisely: If you’re not sure how much milk your baby will eat, use smaller storage bags, bottles, or containers. In this way, you can avoid having too much leftover milk and ensure that each feeding is fresh.
10 Tips to Safely Store Breast Milk in the Fridge
It’s necessary to consider storing the breast milk after every pump when your baby is not at your side. For example, if you’re going to go back to work, or just go out to meet friends, at this time, you probably have pumped and need to use storage bags or containers to store the breast milk.
That’s why the proper storage of breast milk in the refrigerator is crucial for maintaining its quality and safety. Here are ten detailed tips:
Dos
1. Use Clean Containers or storage bags
To ensure the safety of stored breast milk, always use clean and sterilized containers or bags. Bacteria can easily contaminate milk if containers are not properly cleaned. Use glass or BPA-free plastic containers with tight-fitting lids, or specialized breast milk storage bags designed for this purpose. Before use, wash the containers thoroughly with hot, soapy water and sterilize them by boiling or using a sterilizer.
2. Squeeze out the air
Before sealing the storage bags, make sure there is only the extracted fresh breast milk in the bags. In this way, the breast milk will be much safer, with no circumstances for bacteria to exist and grow.
3. Label and Date
Clearly label and date each storage bag or container of breast milk. This practice helps you keep track of how long the milk has been stored and ensures you use the oldest milk first. Use a permanent marker or a label maker to indicate the date and time of expression. This way, you can easily manage milk storage and avoid confusion about which milk to use.
4. Store in the Back
Put breast milk containers or storage bags at the back of the refrigerator, which is typically cooler than the door or shelves. The lower and consistent temperature helps maintain the milk in a safe condition.
5. Use Within a time frame
Freshly expressed breast milk should be consumed within 4 hours if you don’t store the breast milk in a refrigerator or a freezer. If you need to store the fresh breast milk in the fridge as soon as pumped, the timeframe can be up to 4 days. If stored in the freezer, the time goes up to 6 months. Check the timeframe for each type of breast milk.
6. Keep It Sealed
To keep the fresh breast milk safely in the refrigerator, make sure all the storage bags and containers are tightly sealed. This can prevent contamination and odor absorption. Tight-sealing also helps to maintain the quality and prevent spills or leaks. We generally use storage bags.
7. Use Ice Packs
You can put the fresh breast milk in the refrigerator or freezer for longer storage at home. But it’s inevitable that you’ll go out, how to store fresh breast milk? For example, during travel, if so, use ice packs to help maintain a low temperature.
8. Maintain a Consistent Temperature
Ensure that your refrigerator maintains a consistent temperature of 39°F (4°C) or below. Use a fridge thermometer to check the temperature regularly. In case your fridge goes out, check on the status of the frozen breast milk. If it has been stored in a full freezer and not opened after the power outage, it’s safe to use for 48 hours.
Don’ts
1. Don’t fully fill the storage bags
The frozen breast milk will expand in volume. If you fill the storage bags fully, the bags will be broken after frozen. It’s better to fill the bags at or under 2/3 of the storage bags. Most storage bags have scales and you can store the fresh breast milk following those scales.
2. Better not Mix
It’s not recommended to mix fresh breast milk with cooled or frozen milk that has been placed in the refrigerator or freezer for some time because they’re not at the same temperature level. If you do want to mix them, remember to cool freshly expressed milk before pouring it into the storage bags or containers storing older, previously cooled, or frozen milk. Check this post on how to safely mix breast milk from different days.
10 Tips to Warm Refrigerated Breast Milk
As long as the warmed breast milk can’t be refrigerated again, smartly warming the breast milk would be the first and most important thing for parents. After all, we don’t want to waste a drop of the precious breast milk.
Dos
1. Warm Gradually
Warm breast milk gradually to avoid overheating. Use a warm water bath or a bottle warmer designed for breast milk. Rapid heating can destroy some of the milk’s beneficial nutrients and create hot spots that can scald your baby. Gently warm the milk to body temperature (about 98.6°F or 37°C) for the best results.
2. Test Temperature
You should test the temperature before every feeding. Place a few drops on your wrist to check if the milk is at a safe temperature to eat. The milk should feel warm, not hot.
3. Use Within 2 Hours
Once breast milk has been warmed, use it within 2 hours. Do not leave warmed milk out for extended periods, as it can become a breeding ground for bacteria. If your baby does not consume the milk within this timeframe, discard any leftover milk to ensure safety. Follow the above tips to deal with the leftover warmed breast milk.
4. Reheat Only Once
Avoid reheating breast milk. Reheating milk multiple times increases the risk of bacterial growth and degrades the milk’s nutritional value. Only warm the amount of milk you anticipate using in one feeding.
5. Keep in Warm Water
Maintain warmed milk in a container with warm water if it needs to stay warm for a short period. This method helps keep the milk at the desired temperature without overheating. It’s a good idea to use some fast bottle warmers to warm up the breast milk. However, you should not keep the breast milk in the bottle warmer for a long time, not longer than 2 hours.
6. Use a flowing warm water
If your baby wakes up at night feeling hungry, you probably need to warm up the frozen breast milk. Flow up the breast milk with warm water at around 40° and knead the iced milk at the same time.
Don’ts
1. Avoid Microwaving
Never microwave breast milk. Microwaving will break down important nutrients and enzymes in the breast milk. Additionally, it causes uneven heating, creating hot spots that can burn your baby’s mouth. Always use alternative methods like a warm water bath or bottle warmer to heat breast milk.
2. Swirl, Don’t Shake
Gently swirl the bottle to mix the milk after warming. Don’t shake!!! Shaking the bottle can break down proteins and fats in the milk, affecting its quality. Swirling allows for the even distribution of the milk’s components without compromising its integrity.
3. Don’t warm up directly
You don’t need to take the breast milk from the storage bags or container and power it into a pot or pan for warming up. You just need to warm milk in the storage bags and then pour it into the feeding bottle.
Sources
Components of moms’ breast milk. – By National Libray Medicine.
Breast milk preparation. -By CDC.
