Breast milk is the best possible food to help your baby develop and grow. It contains antibodies, live cells, and other substances to help protect your baby from infection and illness.
If you choose to express your breast milk, it’s important to store your breast milk safely to keep your baby safe and ensure they’re getting all the nutrients they need.
Storing Expressed Breast Milk
Breast milk is suitable for storing due to its antibacterial properties, which help it to stay fresh and discourage the growth of bacteria. When you’re expressing breast milk, it’s particularly important to store it in the right type of container to avoid contamination – we recommend our Breast Milk Storage Bags or Bottles. Remember that shouldn’t be filled to the top, always leave at least 2.5cm of space to allow the milk to expand as it freezes.
How Long Can Breast Milk Stay Out?
Breast milk should be stored somewhere cool as soon as it has been expressed. It is best to avoid storing the milk in the fridge door due to temperature control. Instead, store it in the coldest part of the refrigerator, usually at the back of a shelf.
Storing Breast Milk in the Fridge
Breast milk should be stored in plastic bags or breast milk bottles as soon as it has been expressed. However, keep in mind to not add body temperature breast milk into already chilled expressed breast milk unless it’s a very small amount.
It is best to avoid storing the milk in the refrigerator door due to temperature control. Instead, it’s best to store it in the coldest part of the refrigerator, which is at the back of the shelf that is just above the vegetable compartment.
How Long Does Breast Milk Last in the Fridge?
When you’re expressing milk to use at a later date, it’s important to refrigerate or cool it immediately to ensure it has the longest shelf life possible. The NHS states that when stored correctly, expressed milk will last for:
- Up to eight days in the fridge at 4C or lower.
- Up to three days in the fridge if it’s higher than 4C.
- Two weeks in the ice compartment of a fridge.
How to Store Breast Milk in the Freezer?
If you’re freezing your breast milk, you should always place it in the freezer straight after it has been expressed. It’s recommended to keep frozen breast milk in the middle of the freezer where the temperature is most consistent so it won’t partially thaw.
How Long Does Breast Milk Last in the Freezer?
The NHS states that when stored correctly, expressed milk will last for:
- for 2 weeks in the ice compartment of a fridge
- for up to 6 months in a freezer, if it's -18C or lower.
Breast Milk Storage Containers
Refrigerated or frozen milk should be stored in either sterilised hard-sided plastic or glass containers with well-fitting tops, sterilised BPA or BPS free containers, or breastmilk bags that are specifically designed for storing expressed milk, such as Lansinoh® Breast Milk Storage Bags.
It’s also important to mark the container with a date so you know how old it is and when to use it by.
Tips for Storing Breast Milk
- Wash your hands before expressing.
- Wash your express milk pump and containers in hot, soapy water, rinse well, and allow to air-dry before use. Alternatively, you can wash and dry in a dishwasher.
- As well as marking the date on the container, also include your baby’s name on the label if your baby attends nursery or a childminder to avoid the milk getting mixed up with another child’s.
- If you’re travelling and need to take expressed milk with you, chilled breast milk can be carried in a cool bag with ice packs for up to 24 hours.
- It’s best to store expressed breast milk in smaller quantities to avoid waste.
How to Warm Breast Milk?
Warming up breast milk needs to be done efficiently and carefully, especially if you are wanting to use frozen breast milk.
How to Defrost Breast Milk?
Warming up breast milk needs to be done efficiently and carefully, especially if using frozen breast milk.
- If your milk is frozen, you can easily defrost it in the fridge – just remember to use it within 24 hours after defrosting.
- Alternatively, thaw and heat breast milk under warm, running water, or in a bowl with warm or hot water.
To preserve the nutrients in your milk, it’s important to not heat your breast milk in a pan on the cooker. It’s also recommended to never heat your expressed milk in the microwave as it won’t heat the liquid evenly which could cause hot spots and hurt your baby.
How Long Does Breast Milk Last Once Defrosted?
One the breast milk is defrosted, use straightaway. Once your baby has drunk from the bottle of breast milk, it should be used within 1 hour, and anything left should be thrown away. Do not refreeze ilk that has been defrosted.
How to Defrost Breast Milk Fast?
If you need to defrost your milk more quickly, hold the container under a cool running tap and gradually increase the temperature of the water to heat the milk to a safe feeding temperature. Alternatively, immerse the container in a bowl of warm water. If the water has become cold before the milk has defrosted, take the milk out and reheat the water if necessary.
Once you’ve heated your milk, gently swirl the milk before testing the temperature. Avoid shaking vigorously as it could damage some of the live components of the milk.
Why Does My Breast Milk Have a Funny Smell?
In rare cases, some mothers may find that their milk smells soapy or not nice after storing. This happens when the milk produced is high in lipase, an enzyme that breaks down fat in the milk.
Depending on the level of lipase, some mothers notice this smell after their milk has been stored in the fridge, others may notice it only after the milk has been frozen for a while and then thawed. If it does smell when thawed, in future, the milk can be scalded before freezing to deactivate the lipase.
If you have any more questions about breast milk storage, speak to your midwife, health visitor or doctor for support. Or for further reading around breast milk, check out our handy guides on the breast pumping basics and feeding expressed breast milk.
