By knowing how to store it safely, you can reduce the risk of any of your precious expressed breastmilk going to waste.
Any parent who has expressed breast milk knows how precious it is. Even spilling the smallest drop can be heart-breaking – whoever said "don’t cry over spilt milk" has never expressed breast milk!
But, by knowing how to store it properly for future use, you can reduce the risk of any going to waste and keep your baby safe.
Breast milk is very resilient and stores well due to its antibacterial properties, so don't worry if you're unsure how to store your expressed milk – that's why we're here to help!
How to prepare to store expressed breast milk
Before you begin storing your expressed breast milk, wash your hands thoroughly and make sure that the container you’re going to use is sterile and appropriate. It’s also a good idea to make sure you've got what you'll need to label the container and check that you have enough space in your refrigerator or freezer to safely store it.
How to store breast milk
Once it’s been expressed, breast milk can be stored in the fridge or freezer in sterile bags, pouches, or bottles with well-fitting storage lids.
Can I store breast milk in zip-lock bags?
Technically you can store your expressed breast milk in food-safe zip lock bags, but we’d recommend that you use specially designed breast milk storage bags that are pre-sterilized instead, and you should avoid bags that are not designed for freezing because they might burst or tear. Our storage bags and pouches are perfect because they're already sterilized and ready to be used right away!
Can I store breast milk in mason jars?
If you’re going to pop your expressed breast milk in the fridge, it’s ok to store it in a sterile glass mason jar with a securing fitting lid, but if you’re planning on freezing it, we advise that you use a plastic container instead because liquids expand once frozen and may cause glass jars to crack or smash.
Can I put breast milk that was pumped at different times on the same day into one container?
Yes, it's fine to do this, and don’t worry if it's separated into layers after being stored – this is normal (it's just the hindmilk and foremilk). All you need to do is give it a gentle swirl to re-mix before you feed your little one.
How to label breast milk
You should always label your chosen container, pouch or bag with the date and time the milk was expressed, so you can use the oldest batch first. It can help to add a 'use by' date too, and if your baby is going to have the milk at a childminders or nursery, clearly add their name and ask your care provider if they have any other requirements for how it should be labelled or stored.
If you're going to freeze the milk, it's also handy to write on the amount because milk can expand once frozen, and it can be tricky to see just how much you've got.
How to properly store breast milk
Breast milk can either be frozen or refrigerated depending on when you’re planning to use it.
How to store breast milk in the fridge
Breast milk can be stored in the refrigerator between 32°F and 50°F.
It’s best to put your expressed milk in the fridge as soon as possible once it’s been expressed, and to protect breast milk from temperature changes as the door opens and closes, don’t store your expressed breast milk in the refrigerator door. Instead, store it as close to the back of the fridge as possible.
How to store breast milk in the freezer
Breast milk can be stored in the freezer for up to six months, so if you’re not planning on using your expressed milk right away and you want to store it for longer than five days, pop it in the freezer as soon as you can after expressing to preserve the quality and nutrients.
When freezing breast milk, you should avoid using glass containers, and it's a good idea to leave a 2.5cm gap at the top of your chosen container for expansion.
It's easiest to freeze breast milk in individual feed quantities of 60 to 125ml or 2 to 4 oz. – at least until you know how much your baby has per feed – then it'll be ready to be defrosted when needed. You can also store smaller quantities of around 30ml for days when your baby is feeling extra hungry!
It’s always helpful to store your newly pumped milk at back and clearly label it with the date it was expressed, that way, when you’re reaching for some frozen milk to give your baby, you’ll always start with the oldest milk first.
How many days can you store breastmilk in the refrigerator or freezer?
Just like any other foodstuff, breast milk will expire over time. The amount of time breast milk lasts will depend on whether it's stored in the refrigerator or freezer, and at what temperature. You can buy special refrigerator and freezer thermometers to help you monitor this.
The longer you store your expressed milk, the more you should consider…
- Cleanliness and hygiene while expressing, storing, and handling breast milk.
- Storing breast milk at appropriate temperatures (use refrigerator and freezer thermometers).
- Checking for bad tastes and smells, which will tell if your milk has gone off. You should always pour away any milk that smells sour and don’t give it to your baby.
You can store freshly expressed breast milk:
- at room temperature (below 77°F) for six hours
- refrigerated at 41-50°F for three days
- refrigerated at 32-39.2°F for six days
- in the freezer for up to 6 months
You can store thawed frozen breast milk that’s not warmed:
- at room temperature (below 77°F) for 4 hours or less
- at back of the fridge for up to 12 hours
Please note, these guidelines explain how long you can store breast milk for a full-term baby with no additional health concerns.
If your baby has been ill or was born prematurely, it's best to discuss this with your health professional to check that the same storage times apply, and if you're taking colostrum or expressed breast milk into the hospital, follow their advised storage and transport times.
- Never defrost or heat breast milk in a microwave.
- Never re-freeze previously frozen breast milk and throw away any unused breast milk after freezing.
- Breast milk stored in the fridge but intended for freezing should be frozen within 24 hours.
- Do not boil breast milk.
How to store breast milk when travelling
If you want to take some expressed breast milk with you when you go out, make sure it's in a securely sealed container to avoid spills, and that it stays cold until needed. Our insulated bottle bags are perfect for protecting your milk on the move.
For longer journeys, it's handy to know that breast milk that's been chilled in the refrigerator can be stored in a cool bag with ice packs for up to 24 hours. If no ice packs are available when transporting expressed breast milk, make sure it's used within four hours.
How to safely thaw frozen breast milk
Remember to use the oldest breast milk in your freezer stash first.
The best way to defrost breast milk that's been frozen is to leave it in the refrigerator to thaw out completely. Once it’s defrosted, you can store it in the refrigerator for up to 24 hours before it’s used if you haven’t already warmed it up.
However, if you need it to be defrosted right away, you can pop the bag or container in warm water or hold it under warm running water until it's defrosted.
To make your life a little easier, our 3-in-1 Advanced Bottle and Pouch Warmer is equipped with a special setting to defrost frozen breast milk!
Whichever way you defrost frozen breast milk, it must be used right away once it's thawed. You should never re-freeze it, and don’t be tempted to microwave or heat breast milk on a stove, even if you’re in a hurry. Not only will this destroy the nutrients, but it can also cause dangerous ‘hot spots’ which can burn your baby’s delicate mouth.