Durable, leak-proof, and made with a self-standing base and spout for easily filling and pouring, our single-use milk bags are just one more way we’re making your pumping and feeding routine even easier. 

Store your milk safely. Feed with confidence.

At Willow, we’re on a mission to help moms reach their feeding goals. 

We got our start changing everything about how it felt and what it meant to pump  — showing them how to feed their babies without cords or confusion, and with the freedom they needed to live their lives fully. 

Now, we’re continuing to solve your most meaningful challenges at every stage of your journey, no matter when or where you feed. Enter: Breast Milk Storage Bags, designed to help you pump and store your milk safely with ease. 

Like all of our products, they’re durable and made with materials designed to bring you peace of mind. So whether you’re building a freezer stash or transporting your milk home from work, we know they’ll become one of your most-used feeding essentials. 

Featured in our milk storage collection. 

Our Breast Milk Storage Bags join our Glass Breast Milk Pitcher and Portable Breast Milk Cooler, giving moms even more options for milk storage — whether you’re pumping at home or on the go. 

Explore the Breast Milk Storage Bags 

Our milk bags can be stored in the refrigerator or freezer, and easily labeled with a marker or ballpoint pen. (If freezing your bags, we recommend laying them flat for more compact storage and faster freezing!)

• Holds 8 oz (240 ml) of milk 
• Leak-proof, double-zip seal for durability
• Spout and self-standing base for easy filling and pouring
• Pre-sterilized with a tamper evident, tear-away top
• Made without BPA or phthalates

How to use 

• Tear away top seal, unzip and pour in milk. Do not fill above the maximum fill line.
• Remove excess air from the bag and zip shut.
• Label bag with date and milk volume.
• Store bag upright on a refrigerator shelf or freeze flat.

Best practices for milk storage

Storing Milk 

Before storing your milk, make sure to label your storage container with the time, date, and amount pumped. 

• Room temperature: It is optimal to keep your milk at room temperature for no longer than 4 hours, although 6-8 is acceptable in very clean conditions. 
• Fridge: Breast milk stored in the fridge is optimally used within 4 days, although 5-8 days is acceptable in very clean conditions. 
• Freezer: It is best to use frozen milk within the first 6 months, although it can remain in a deep freezer for up to 12 months.
• Cooler bag: Whether you have an insulated bag with ice packs or an insulated thermos, breast milk should be used (or transferred into the fridge or freezer) within 24 hours.

Thaw milk in the refrigerator, under a stream of warm water, or in a container of warm water. Do not place bags in the microwave.

Resources for milk storage 

We’ve curated articles from our blog to give you expert-backed tips on safe milk storage. 

Complete Guide to Storing Breast Milk
How to Store Breast Milk at Work
How to Thaw Breast Milk for Safe Consumption