How to Properly Store and Freeze Breast Milk

Storing and freezing milk in feeding-sized portions can help minimize waste. While you can always defrost more milk, you can’t reuse milk that has been thawed (more on that later). Remember to leave a little space at the top of the container, as milk will expand slightly when frozen. After all, you worked hard for that milk—why waste it if you don’t have to?

• Label each baggie of milk with the date and time. Always use the freshest milk first, it’s richer in vitamins, protein, fat, antioxidants, probiotics, and immunoglobulins (which are like little magical goblins that combat germs, helping to keep us healthy).
• Breast milk is indeed magical! Its composition varies throughout the day, so whenever possible, try to use milk pumped at the same time. For instance, if it’s evening and you’re selecting a bag to thaw, choose one pumped in the evening for sleep-supporting nutrients! Conversely, morning milk is like a refreshing cup of coffee for your baby, so provide them with morning-expressed milk.
• Here’s something else fascinating: Your body alters the milk based on your baby’s cues, including the scent of their head and even their poop! Yes, poop! Your brain recognizes the odor and produces nutrients tailored to their needs. Additionally, your nipple acts as a two-way valve, gathering components from their saliva and releasing nutrients, immunoglobulins, macronutrients, and micronutrients in response to their requirements.
• After thawing, use the milk within 24 hours. Frozen human milk that has been defrosted for 24 hours should not be left at room temperature for more than 2 hours. Avoid refreezing milk that has already been thawed.
• Newly expressed warm milk should not be combined with cooled or frozen milk, as it can rewarm the already frozen milk. It’s best to cool the freshly expressed milk before adding it to older stored milk.
• Refrigerated and frozen human milk may have a different odor compared to fresh milk due to lipase-mediated triglyceride breakdown, which releases fatty acids. However, there’s no evidence that infants will refuse human milk because of this odor. Many foods we enjoy, such as eggs, cheese, and fish, have strong odors that don’t affect their taste. And who doesn’t enjoy a bit of stinky cheese?
• When you’re ready to thaw your frozen milk, simply place the sealed bag into a lukewarm water bath and wait for the milk to reach room temperature. Gently swirl the bag to blend the creamy fat layer with the more liquid portion.
• There’s no need for the milk to be warm; in fact, lukewarm breast milk is known to retain higher fat content. This is because warmer fat tends to stick to the container, while cooler milk is less likely to adhere.
• Avoid using a microwave. It can destroy nutrients and makes it hard to control the temperature.
• If you have leftover milk, don’t worry! You can use it in a milk bath to soothe skin and reduce irritation.
• For irritated, cracked, red, or sore nipples, consider using nipple balms or creams. Additionally, hand express a drop or two of milk and apply it to your nipples; this can help breast milk heal any minor wounds. Silverettes, small silver cups, are also excellent for healing tissue—just wear them inside your bra or shirt when you’re not nursing.