a bottle storing breastmilk with baby in background

We’ve rounded up all your options for storing that liquid gold

Whether you’re building a stash before you head back to work or out of town, setting aside milk for date nights, or exclusively pumping around the clock, you’ll need to properly store your precious pumped milk. Which option you choose will depend on your storage space, baby’s feeding needs, cost and other personal preferences. Here’s a quick overview of the best ways to contain and store breast milk.

1. Breast milk storage bags

One of the most popular choices for storing breast milk is zip-top storage bags (we like ones with a double zipper to prevent leaks!). These pre-sterilized bags are thicker than your typical zip-lock bag and each hold up to roughly six ounces of milk. Most brands have the ability to attach directly to your breast pump. Just make sure not to fill them more than the recommended capacity to prevent leaks.

We love that storage bags are easy to label with the date and number of ounces, and your child’s name if they are in daycare. When prepping to freeze, squeeze out the excess air, leaving a little room for liquid expansion while freezing, and zip the bag securely. Lay them flat so you can easily store them without taking up too much extra space. Some moms like to keep their bags organized from oldest milk in front to newest in back, so it’s easy to rotate through the stash.

It doesn’t happen too often, but when thawing, beware of cracks along the seams and in the corners that could result in leaks. Sturdy, thick bags seem to hold up best, and to be safe, you can thaw your bags in a clean bowl or cup in the fridge. Breast milk storage bags are disposable, which is a pro if you want to skip washing or a con as it produces waste and requires you to continually buy more.

Here are a few of our favorite storage bags:

  • Kiinde: attaches to most pumps and has nipple and bottle attachments, which means you can pump, store and feed from the same bag
  • NUK: known to be less prone to leaks, waterproof so you can easily thaw under warm water without diluting milk
  • Dr. Brown’s: sturdy material, less prone to leaks, very secure double zipper
  • Lansinoh: lower cost, spout at the top, latest design allows moms to attach to pump with an adaptor

2. Plastic bottles

Screw-top plastic storage bottles are a great way to store milk on the go, in the fridge or even in the freezer. Here, we’re talking about the bottles that attach or come with your pump or other similar food-safe, BPA-free bottles. If you plan to freeze milk in plastic bottles, you’ll want ones with an air-tight seal. Avoid filling them to the very top, as you’ll need a little extra space for the liquid to expand while freezing.

The best part about using plastic bottles for storage? You can use them for pumping, storing and feeding, which saves time and cuts down on washing multiple bottles. They are reusable, so you won’t be producing waste or buying more, but you will have to wash them after each use. Bottles are stronger than storage bags and usually won’t leak, even if they’re stashed in your work tote or diaper bag. But if you’re building a freezer stash, bottles take up more space than storage bags and require a bigger expense upfront.

3. Glass containers

Similar to plastic bottles, glass containers usually feature a tight, screw-top lid. If you go the glass route, choose freezer-safe containers that are small enough that you won’t have to thaw too much milk at a time. As with other storage options, be sure to leave room for expansion if you use them in the freezer.

With glass, there are none of the concerns with chemicals that some moms may have with plastic. And glass containers are multi-use as you can use them to store homemade baby food when that phase arrives. Like plastic bottles, they can be bulky if you’d like to stash a lot of them in the freezer. Glass can also be at risk of breaking, especially if you want to use them to transport milk on the go, and they are more expensive than plastic bags or bottles.

4. Breast milk trays

Breast milk trays feature small compartments for breast milk (or homemade baby food when you get to that point!). They look similar to a typical ice cube freezer tray with an added cover to protect the milk from germs, odors and freezer burn. It’s important to note that regular ice cube trays are not designed to store milk.

These breast milk trays are for freezer storage (not fridge), easy to stack and reusable. They are ideal for freezing small portions so you can only thaw what you need—no wasting! And because the “cubes” are smaller, they freeze and thaw quickly. This portion size makes them a great option for newborns who drink only a couple ounces at a time or for those times when you just want to mix a bit of milk with baby food or cereal. You can also remove frozen milk from the tray and pop the cubes into a zip-top freezer bag or larger container, so you can then reuse the tray.

On the other hand, if you want to create a larger stash or freeze bigger portions, trays might not be the best option for you. Breast milk trays require carefully transferring milk from the bag or bottle you pumped into, and once frozen, you’ll likely have to use your (clean) hands to remove the breast milk cubes from the tray, which opens up a small risk of contamination.

No matter which storage option you use, you’ll want to follow safe storage guidelines, including the temperature and time stored, as well as thawing, feeding and cleaning processes. If you have any questions or want some guidance on which method of breast milk storage is best for you, reach out to the experienced IBCLCs with Ashland Health’s Lactation Network. We know every mom’s breastfeeding journey is a bit different and finding what works best for you is the easiest way to success.