One Friday evening when my second daughter was 6 months old, my husband and I were going out for a rare date night. In preparation, I pumped a few ounces of breast milk prior to heading out and set it on the counter so it would be fresh for her. A few hours later when we returned home, my mom broke the news that my daughter wouldn’t take the bottle (surprise, surprise) and had instead eaten Puffs all evening. She stuck my breast milk in the fridge, thinking the baby might drink it at some point over the weekend. By Sunday evening, though, it was clear she wasn’t going to drink a bottle when I was around.
I wasn’t sure what to do with the milk. Did I have to (gasp) toss it? Was it ok to freeze it at this point? I didn’t want to risk giving my daughter spoiled milk, but I also didn’t want to throw away perfectly good breast milk just because I wasn’t sure how to handle this particular situation.
Standard breast milk storage guidelines from the CDC are pretty straightforward. They provide the below chart outlining rules for room temperature, refrigerator, and freezer storage of breast milk:
However, other experts endorse slightly less stringent guidelines that still seem prudent enough to me. For example, Medela’s storage guidelines state you can keep freshly pumped breast milk at room temperature for up to 6 hours and in the fridge for up to 8 days. What gives?
The CDC is always going to err on the side of caution. If there’s a range of acceptable storage times, they’re going to recommend the most conservative end of that range, as they don’t want anyone getting sick based on their guidelines. We scoured the internet for recommendations from a lot of different sources – government entities, large hospitals, breast pump companies, lactation experts – and came up with our own rules to live by, using the ‘somewhere in the middle’ approach:
Now, what about those scenarios that don’t fall within these guidelines? What do you do then? How do you know if your breast milk has gone “bad”? And what happens if you unintentionally give your baby “bad” breast milk? We’ll answer all of that and more.
Why Proper Breast Milk Storage is Important
I think we’re all aware breast milk isn’t quite like the milk we buy at the grocery store. It hasn’t been pasteurized, which means it hasn’t gone through the process of heating it up quickly and then cooling it down, thereby eliminating pathogens and extending shelf life. As a result, we must handle it with more care. The good news is breast milk naturally has properties that slow the growth of bad bacteria; the bad news is these properties start to deteriorate after a few days of refrigeration. How many? As we discussed, the CDC recommends 4 days, but many other experts say you could push it to as many as 8 days in a refrigerator.
Let’s say you’re coming up on the end of your breast milk’s shelf life, and you’re wondering if it’s still fresh. How will you know for sure that it’s ok to give to your baby? Basically, the same way you know if cow’s milk is still fresh:
--Smell it: Does it smell sour or spoiled?
--Look at it: Are there any chunks in it? When you swirl it around, does it easily mix up, or is it still chunky?
--Taste it: If all else fails, try it yourself. If you think it tastes terrible, your baby will think so, too.
If you unintentionally give your baby “bad” breast milk, don’t stress too much. The baby will likely vomit up the spoiled milk and may have an upset stomach for a little bit, but otherwise, she should be fine.
Standard Breast Milk Storage Guidelines
Let’s talk about the right way to handle your breast milk from the start. Before you pump or handle breast milk, always wash your hands thoroughly with soap and water. If you don’t have a sink handy, make sure the hand sanitizer you use contains at least 60% alcohol. Also, inspect the pump parts and tubing to make sure they’re clean and free from mold. You may want to wipe everything down with disinfectant wipes periodically.
When you’re done pumping and ready to store your milk, always use breast milk storage bags or containers with secure closures to prevent any leaks. Look for BPA-free storage bags and containers, specifically avoiding any bottles with the recycle symbol number 7, which indicates there may be BPA present. Label the bag or bottle with the date; you may also want to indicate how many ounces you pumped, as breast milk swells when frozen and the bags appear that they have more milk in them than they do. For this reason, don’t fill the bags all the way up to the top, as the zipper closures could bust open in the freezer.
Always store your milk in the center of your fridge or freezer and not on the door, as the temperature is more stable deep within a fridge or freezer. Also, to give you more flexibility when thawing, store your breast milk in smaller amounts (2-4 ounces) so you don’t waste any milk in case the baby doesn’t finish the bottle.
When you’re ready to thaw your milk, always use the oldest breast milk first. Never thaw or heat breast milk in a microwave, as it can destroy the nutrients in your milk and could get too warm for the baby. Instead, you could thaw it in the refrigerator overnight, making sure to use it within 24 hours of the time when it was completely thawed. For faster thawing, set the bag or bottle in a container (I always used a large coffee mug) filled with room temperature water, or place the bag or bottle under lukewarm running water.
To feed the baby, you don’t have to warm your breast milk – it can be served at room temperature or cold, straight from the fridge. It all depends on what your baby prefers. If you do warm it, make sure the breast milk storage bag or bottle stays sealed close while warming, and never heat it directly on the stove or in the microwave. Instead, similar to how you thawed it, warm your milk by placing the bag or bottle in a separate container of warm water for a few minutes or place it under warm running water.
Carefully open the container and transfer the milk (if necessary) to a feeding bottle. Swirl the milk to ensure the fat is mixed up and there are no hot spots, and then test a few drops of the milk on the inside of your wrist to ensure it’s an appropriate temperature. Once your milk is warm or has been brought to room temperature, use it within 2 hours. Once it’s been thawed, you should never refreeze breast milk, which is why you want to make sure you don’t thaw more than you need!
Special scenarios: What to do when…
When you’re pumping on the go, breast milk can be stored in an insulated cooler bag with ice packs for up to 24 hours. Make sure it stays cold the entire time and doesn’t warm to room temperature. As soon as you can, transfer your milk to fridge or freezer storage.
If you’re going to be away from your baby for a few days, make sure your hotel room has a fridge or freezer that will be large enough to store your milk and your ice packs. You may need to buy a larger cooler bag or a large Styrofoam cooler to transport your milk back home.
When flying, you’re allowed to have 3.4 ounces of breast milk in your carry-on bag without any trouble. If you have more than 3.4 ounces, notify a TSA officer as you’re going through security that you have breast milk than needs screened separately. Your milk will likely be screened by X-ray and may also need to be tested for explosives. If this happens, you’ll just need to transfer a few drops of your milk into a separate container, if possible. If you do not want your breast milk to be X-rayed or tested, let the TSA officer know, and they’ll go through a few additional steps to make sure you’re not a terrorist (nope, just an overtired mom).
You haven’t used the breast milk in your fridge yet, and it’s been a few days.
The guidelines say if you don’t think you’ll use your breast milk within 4 days, freeze it right off the bat. But what if you DID think you’d use it, and life didn’t work out the way you planned…now what? Similar to my conundrum that I shared at the beginning of this article, it’s difficult to know whether it’s ok to freeze breast milk that is at the end of its so-called “shelf life” in the refrigerator. Good news, though: According to the Mayo Clinic, if refrigerated breast milk isn’t used within 3 days, it can still be frozen at that point. Hooray!
You have breast milk in the fridge, and you just pumped some more.
Do you have to use two different containers for milk pumped in the same day? No, but you do need to handle it properly. Thoroughly cool the fresh milk before adding it to the previous refrigerated milk. You don’t want to mix warm and cold milk because the warm milk will cause the cold milk to partially thaw.
If you’re pumping on two separate days, it’s best to store them in separate containers, as they’ll have different expiration dates.
Your worst nightmare happened – the power went out! Do you have to throw away all your frozen milk?
It depends on how long the power is out and what kind of freezer you have. If it’s a deep freezer and the door stayed closed the entire time during the outage, you probably have a better shot. While the power is off, resist the urge to check on your milk, as opening the freezer door will warm up the freezer. Once the power is back on, check to see what condition your milk is in. If it’s a little bit slushy, but still has ice crystals, it can safely be refrozen. If it’s totally thawed, though, you should put it in the refrigerator and use it within the next 24 hours, and then toss whatever is left.
I have more frozen breast milk than my baby could ever drink! Do I have to throw it all away?
This is a heartbreaker! With both of my daughters, I had to throw out all the breast milk I pumped from the first 4 weeks of their lives because I discovered they were sensitive to dairy in my diet, and I knew I couldn’t give them my dairy-laden frozen breast milk. I made my husband toss it and told him not to tell me when he was doing it. If you’re an overproducer, or if for some reason, your baby simply won’t be able to use all the breast milk you painstakingly pumped, you don’t necessarily need to throw it away. You could reach out to local friends and acquaintances with babies to see if they would be interested in taking your breast milk, or you could donate to a breast milk bank. For most of these companies, you need to be in good health, not regularly using medications or herbal supplements (with a few exceptions), be willing to take a blood test, and be willing to donate a minimum amount of breast milk (varies by breast milk donation bank). It’s ideal if you can find one located in your area, but if not, you can typically ship your breast milk.
Pumping and storing breast milk can feel like a full-time job, but it’s worth it! The nutrients and immunities you’re giving your baby are priceless, and proper handling of your breast milk ensures those nutrients remain intact.
About Katie Stansberry
Katie Stansberry is a work-from-home mom of two sweet girls and the creator of Breastfeeding Bliss. After struggling at the beginning of her breastfeeding journey, she wanted to create a happy place where breastfeeding moms could find practical tips, positive inspiration, and the newest and best breastfeeding products. On her "Back to Bliss" breastfeeding blog, she shares her personal stories and tips for making breastfeeding an easier and more enjoyable experience.