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Expert Shopper Baby & Kids

The best breast milk storage bags

Which breast milk storage bag is best?

Breast milk storage bags are a convenient way for moms to have extra milk on hand for babies.

Breast milk storage bags are designed to be freezer-safe and highly puncture-resistant to combat spills and leaks. Many bags are also marked with measured increments to help moms track how much sustenance their babies are receiving. Others are marked with labels that can be written on to indicate when the milk was pumped and frozen to eliminate guesswork.

If you’re ready to compare breast milk storage bags, give our buying guide a read. We’re covering everything you need to know, plus we’re sharing a few recommendations. Our top choice, Medela Breast Milk Storage Bags, is equipped with a double seal to prevent leaking, even when the bag lays flat.

What to consider when choosing breast milk storage bags

Filling the bag

There are two types of breast milk storage bags — those that attach directly to pumps and those that don’t. The most seamless option is the former. Unfortunately, only select bags work with a pump.

Bags that don’t attach to pumps require milk to be transferred into them, which can be somewhat messy. On the upside, these breast milk storage bags often have superior seals as well as lay-flat or upright designs.


It’s best to use refrigerated breast milk within three days; otherwise, you need to freeze it. Most breast milk storage bags are freezer-safe. They may have stackable designs or be contoured in a manner that fits inside a dedicated freezer box made by the same manufacturer.

Bag design

The majority of breast milk storage bags hold five to six ounces of milk, though a few varieties hold up to eight ounces.

In terms of construction, it’s recommended to choose bags that are free of BPA, PVC, and phthalates. For added safety, it’s a good idea to stick with breast milk bags that are pre-sterilized. Thicker bags are best since they’re more durable and puncture-resistant.

Breast milk storage bags features

Pre-printed measurements

To help you keep track of how much babies consume at each feeding, many breast milk storage bags have preprinted measurements. They usually list measurements in both ounces and milliliters. These are especially important features to parents of preemies or babies with other health concerns.


Labels are a valuable feature in breast milk storage bags because they help you cycle through milk in a timely fashion. Write the date and time the milk was pumped, as well as when it was frozen.

Double seals

To keep leaks and spills at bay, it’s best to use breast milk storage bags with double seals. In the event one seal bursts, the secondary seal provides peace of mind. Some breast milk storage bags even have bag-within-a-bag designs, in which the breast milk is essentially double-bagged for added protection.

Breast milk storage bags price

To better understand the prices of breast milk storage bags, we’ve broken down the cost per bag. Inexpensive breast milk storage bags cost $0.13 per bag, though most of these have single zips and hold smaller volumes. Mid-range breast milk storage bags cost approximately $0.15 per bag and feature labels, measurements, and double seals. Premium breast milk storage bags cost closer to $0.20 per bag and in addition to having a wealth of features, their construction quality is superior.

Breast milk storage bags FAQ

Q. Are breast milk storage bags microwavable?

A. Most aren’t, and it’s not a design flaw. Microwaving frozen milk to thaw it can be problematic because it causes milk to thaw unevenly. Instead, parents are encouraged to simply place the frozen bag under warm water of a running faucet for safer, more even defrosting.

Q. Do I really need breast milk storage bags with labels?

A. It’s strongly preferred for safety reasons. Parents of babies who go to daycare also need bags with labels to distinguish them from others kept in the daycare’s freezer.

Breast milk storage bags we recommend

Best of the best

Medela Breast Milk Storage Bags

Our take: A reliable option approved by physicians that has a lay-flat design for easy storage.

What we like: Comes with 100 six-ounce, BPA-free bags. Bags are strong and puncture-resistant. Reliable, leak-free zip closure.

What we dislike: Doesn’t attach to the pump, so milk must be transferred into them.

Where  to buy: Sold by Amazon

Best bang for your buck

Lansinoh Breast Milk Storage Bags

Our take: Remains a favorite among moms for its affordability and secure double-seal closure.

What we like: Bags feature labels that are easy to write on. Even when frozen, bags are easy to open. Bags connect directly to the pump.

What we dislike: A few parents noticed that the bags leak during thawing.

Where  to buy: Sold by Amazon

Worth checking out

Unimom Breast Milk Storage Bags

Our take: A convenient design that’s made to stand upright by itself thanks to a contoured bottom.

What we like: Bags are made with BPA-free plastic. Pre-marked with ounce measurements for easy tracking. Seals hold up exceptionally well.

What we dislike: Without a lay-flat design, the bags take up considerable freezer space.

Where  to buy: Sold by Amazon


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Sian Babish  writes for BestReviews. BestReviews has helped millions of consumers simplify their purchasing decisions, saving them time and money.

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