Safe Breastmilk Storage Guide
You’ve put in the work—and every drop of breastmilk counts! Proper storage keeps your breastmilk nutrients intact and ready when your baby needs them. From freezing and thawing to rewarming, this simple guide (plus bonus tips!) makes it safe and easy.
How to Store Breastmilk
Here at Lansinoh, we recommend following the breastmilk storage guidelines from the Centers for Disease Control and Prevention (2024). If you ever feel unsure or have questions, know that you're not alone; your healthcare provider, lactation consultant, or our friendly Customer Care Team is always here to support you.
Freshly Expressed or Pumped Breastmilk
Room Temperature (77°F or cooler): Breastmilk can be safely stored for 4 hours at room temperature.
Refrigerator (40°F): Breastmilk can be safely stored in the fridge for up to 4 days.
Freezer (0°F or colder): Frozen breastmilk can be stored for up to 12 months, but it’s best to use it within 6 months for optimal quality.
Thawed Breastmilk
Room Temperature (77°F or cooler): Thawed (previously frozen) breastmilk can be safely stored at room temperature for 1-2 hours.
Refrigerator (40°F): Thawed breastmilk can be safely kept in the fridge for up to 1 day (24 hours).
Freezer: NEVER refreeze breastmilk after it has been thawed
Leftover From a Feeding
If your baby didn't finish their bottle, you can safely give them what’s left, as long as it’s within 2 hours of when they finished feeding.
Safe Breastmilk Storage Chart
Whether you're building your stash for the first time or just figuring out your routine, let's walk through how to store breastmilk in the fridge for short-term use and how to store breastmilk in the freezer for longer periods.
What Type of Container Should You Use to Store Breastmilk?
To keep your breastmilk safe and fresh, refrigerated or frozen milk may be stored in:
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Breastmilk storage bags specifically designed for freezing and storing breastmilk, like Lansinoh Breastmilk Storage Bags. Did you know you can pump directly into our bags? No messy transfers are needed!
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Breastmilk storage bottles: choose bottles designed for pumping, storing, and transporting breast milk.
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Hard-sided plastic or glass containers with tight-fitting lids.
How Do You Thaw Frozen Breastmilk?
You can refrigerate frozen breastmilk overnight or place a sealed bag or container in warm tap water or a clean, empty container. It’s normal for the milk to separate as it thaws. Massage the milk storage bag to recombine the milk. Thawing breastmilk is easy, but it’s important to handle it gently to preserve all those valuable nutrients. Here’s how:
Refrigerator Method
Place the frozen milk in the refrigerator overnight.
Warm Water Method
Submerge the sealed bag or container in a bowl of warm tap water.
Room Temperature Method
Leave the sealed bag at room temperature for a short time.
Important: Never use boiling water or a microwave to thaw breastmilk, as this can destroy nutrients and create dangerous hot spots.
How Do You Store Thawed Breastmilk?
Once the breastmilk is thawed, it can be stored in the refrigerator for up to 24 hours. However, it should never be refrozen.
How Do You Warm Breastmilk?
To warm breastmilk:
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Place the sealed bag or container under warm running water or in a bowl of warm water. Do not bring the milk to a boil, as this can damage some of its nutrients.
- Always test the temperature on your wrist before feeding.
More Breastmilk Storage Tips
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Leave space for expansion: When freezing, leave about an inch of space at the top of hard-sided containers or fill Lansinoh Breastmilk Storage Bags no more than the 6-ounce mark. This prevents leaks as the milk expands.
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Squeeze the bag gently from the bottom to the top, pushing any air towards the top. Zip the bag closed, leaving a small opening in one corner to let out any remaining air, then close the bag completely.
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Pro Tip: You’ll know Lansinoh’s Milk Storage Bags are securely closed when the pink and blue double zippers turn purple, and you hear a “click.”
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Freeze flat: Lay storage bags flat to freeze. This saves space and speeds up thawing.
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Label everything: Write the date and your baby’s name on each bag or container, especially if your baby is in daycare.
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If you are pumping and storing your breastmilk at work in a common refrigerator, make sure you label it with your name or put it in a bag (also marked) so it is not mistaken for regular milk.
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Store strategically: Keep frozen breastmilk in the middle to the back of the freezer where the temperature is most consistent. Avoid storing breastmilk in the door.
Frequently Asked Questions
What is the best way to thaw a frozen breastmilk storage bag?
Frozen breastmilk storage bags can be thawed in the refrigerator, at room temperature, or placed in a bowl of warm tap water. Never use extremely hot or boiling water on a stovetop or microwave breastmilk to defrost, as this process may destroy breastmilk nutrients and create “hot spots” that could be dangerous for your baby.
Can I pump directly into Lansinoh Breastmilk Storage Bags?
Yes! Lansinoh pumps are designed to let you pump directly into our storage bags. If you’re using a non-Lansinoh pump, you can use our pump-into-bag adapter (sold separately), which works with most standard neck pumps.
How long does breastmilk last in the fridge?
Freshly pumped breastmilk can be stored in the refrigerator for up to 4 days. Thawed breastmilk should be used within 24 hours.
How long does frozen breast milk last?
Frozen breastmilk can be stored for up to 12 months, but it’s best to use it within 6 months for optimal quality.
What’s the best way to organize frozen breastmilk?
Freeze bags flat to save space, then store them upright in a container or bin. Arrange them by date, with the oldest milk in the front so you can use it first.
Can I mix freshly pumped milk with refrigerated milk?
Yes, but only if the freshly pumped milk has been cooled to the same temperature as the refrigerated milk. Never mix warm milk with cold milk.
How do I know if breastmilk has gone bad?
Spoiled breastmilk may have a sour smell or taste. If you’re unsure, it’s better to be safe and discard it.
Can I reuse leftover milk from a feeding?
If your baby doesn’t finish a bottle, use the leftover milk within 2 hours. After that, it’s best to discard it.
How long can breast milk stay out?
Breastmilk can be safely stored at room temperature for up to 4 hours (up to 77°F).
How long does breastmilk last after warming?
Warmed breastmilk should be fed to your baby within two hours.
How to open Lansinoh Breastmilk Storage Bags?
To open a new bag, tear away the safety seal and pull the zipper apart.
When you are ready to feed your baby with breastmilk from a Lansinoh milk storage bag, gently massage the milk in the bag to ensure all fats and solids that may be sticking to the sides of the bag are incorporated back into the milk.
With the bag upright, gently pull apart the top tabs to open the zipper seal. To transfer it to a feeding bottle, gently squeeze the zipper seal on the sides to create a spout with the tabs and pour milk into the bottle.
What is the best way to store my Breastmilk Storage Bag after it’s filled?
We recommend removing excess air from the bag and double-checking to ensure it is not overfilled. When zipping closed, make sure your bag is sealed all the way to the ends. Lansinoh’s Breastmilk Storage Bags feature a double-zipper closure that turns purple when completely sealed, for your peace of mind.
Lay the storage bags flat to freeze. To protect the bags from contact with other frozen items or freezer surfaces, place the flat bags in a container or freezer bag.
You've Got This, Mama
If you have more questions about pumping, storing, or feeding breastmilk, don’t hesitate to reach out to your lactation consultant, healthcare provider, or our Customer Care Team. We’re here to support you every step of the way!
All content found on the Lansinoh.com website, including text, images, audio, or other formats, was created for informational purposes only. The content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.
