How To Store Breast Milk
Whether you're going back to work after maternity leave, going away on a mini-break or just heading out for a few hours, you need to know how to safely store your breast milk if you're breastfeeding and pumping. Here's what you need to know about how long you can keep breast milk and where and how to stash it properly.
How long does breast milk last in the refrigerator?
Breast milk can be stored in the back of the refrigerator for up to four days before it’s moved to the freezer.
How long does breast milk last in the freezer?
You can store frozen milk for six months for best quality but up to a full year safely. The earlier you use up your breast milk, the better, because longer storage can diminish the amount of vitamin C in it. Be aware that the color of stored versus fresh breast milk could be different, but that isn't an indication of whether the milk is still good.
Safe storage guidelines for breast milk
At room temperature
Newly pumped breast milk can be stored at room temperature (no warmer than 77 degrees F), ideally for up to four hours as long as it’s not in the direct sunlight or close to other sources of heat. In some cases, it might be able to keep for up to six hours at room temperature, especially if it's not that warm out or the room is on the cooler side.
In the refrigerator
Breast milk can be stored in the fridge for up to four days. Check the temperature of the refrigerator to make sure it’s around 40 degrees F, and stockpile your loot in the back of the fridge where it’s the coolest. Avoid keeping breast milk on the door of the refrigerator, which is most vulnerable to warmer air when the door opens. After four days, it’s time to move your milk to the freezer.
In the freezer
If you need to freeze your pumped milk, you can use plastic bags designed especially for storing breast milk. Don’t use bottle liners — they’re too thin and could sprout a leak. The temperature of the freezer should be around 0 degrees F. Again, store it in the back of the freezer, furthest away from the door, if possible.
In an insulated bag or cooler
If you need to store breast milk with you when you’re away from home, an insulated bag with frozen ice packs will keep the milk fresh for 24 hours. That's a good option when you’re headed back to work, especially if there isn’t an office refrigerator available for use.
Storage solutions for breast milk
If you’re using storage bags, fill them three-quarters full to allow for expansion as they freeze. To avoid a mess if your storage bag tears, you may want to put your bags inside a sealed plastic container.
A lot of breast pumps come with a couple of bottles you can use for storing the milk and giving it to your baby, and you can buy more if you need to. You can also use your regular baby bottles or even cups with lids that can be closed tightly. Again, fill three-quarters full to allow for expansion as your bottles freeze.
Whether you’re using a bottle or bag, try and avoid BPA, a chemical found in some plastics that has been shown in animal studies to impact the endocrine system and could be particularly problematic to babies during development. Avoid bottles with the number 7 recycling symbol and the letters PC because many of those contain BPA.
Though not quite as common, you can also find milk storage bags that are BPA-free. If your milk will be stored at a day care or other child care facility, make sure that the milk is clearly labeled with your child’s name and the date.
Bear in mind that breast milk doesn't have to be warmed up and if you haven’t already, it’s best to avoid getting your little one into the habit of taking warmed milk because it’s an extra step with no known health benefits. However, if you are heating or thawing breast milk, make sure you don’t microwave it. Doing so can interfere with the nutrients and heat the milk unevenly, which can unexpectedly burn your baby’s mouth. It’s best to heat milk by running warm, not hot, water and then testing the milk before feeding your baby. Make sure that the bottle’s top is secure so that water doesn’t get inside the container and contaminate it.
Freezing breast milk
If you need to freeze your milk, do so in small quantities of two to four ounces at a time. You should label each container with the date, using the oldest milk first, and keep your stash in the back of the freezer, where the temperature is the coldest and most consistent. Don’t add freshly expressed breast milk to frozen milk because it could thaw it out.
Thawing breast milk
Wash your hands carefully before handling any thawed milk. There are two ways to thaw breast milk safely, so you can choose depending on how quickly you need to feed your baby. You can either place the bottle or bag in a bowl of warm tap water, which is the faster option, or you can put it into the fridge and use it within 24 hours.
Experts from Centers for Disease Control and Prevention (CDC) advise parents to try gently swirling, not shaking, breast milk to make sure that the fat blends into the milk before serving it up to your baby. Never thaw milk in a microwave, on the stove or at room temperature, and never use thawed leftovers again or put the milk back in the freezer. Once breast milk is defrosted, make sure to use it up within about two hours, after which the milk needs to be thrown away.
Watch How to Safely Store Your Breast Milk