How to Store Breast Milk

Once you’re able to start pumping and storing your breast milk, you can help make sure your baby is still getting the milk they need – even when you can’t be there with it on tap. Let’s go through the basics on storing and using expressed breast milk safely.

How to store breast milk: Start with the right container

breast milk bottle breastmilk
Step one for storing breast milk is to make sure you’re using a clean, sterilized, BPA-free container to put it in. Choose hard plastic or glass containers, or specially designed milk bags. If you’re using a specialized breast pump, make sure that each part of the equipment has been washed and cleaned in hot water and dish soap before you express.

Once expressed, seal the sterilized container if you’re not going to be feeding straight away. Always write the date and time on each container so you know when you produced it and when you’ll need to use it by.

How to store breast milk: Room temperature, fridge or freezer?

breast milk breastmilk
Breast milk has some anti-bacterial properties, but it’s still important to keep yours stored breast milk at the right temperature for the right time.

Room temperature

Freshly expressed breast milk can be kept at a moderate room temperature (no warmer than 77°F/25°C) for up to 6 hours – but ideally, it should be used within 4 hours.

  • Tips
    Even at room temperature, it’s a good idea to keep expressed milk as cool as possible. Try wrapping the bottle in a cool, damp cloth, and keeping it in a cool, shady part of the room.

In a cooler pack

Freshly expressed breast milk will keep in an insulated cooler bag with ice packs in it for up to 24 hours.

  • Tip
    Make sure the ice packs are in contact with the container of breast milk all the time.
    Try to avoid opening and closing the container as much as possible to keep the temperature inside constant.

In the fridge

In clean conditions, freshly expressed breast milk can be kept in the fridge for up to 5 days. Ideally, it’s best to either use it up or move it into the freezer within 3 days.

  • Tips
    You can “top up” refrigerated breast milk with freshly expressed, but make sure it’s cooled down first. Use the refrigerator or an ice bath to cool it to the same temperature as what’s already in the fridge.

In the freezer

Expressed breast milk can be safely frozen and stored in the back of a freezer for up to 12 months. It’s best to thaw and use the stored milk within 6 months.

  • Tip
    Breast milk will expand as it freezes, so leave an inch of space at the top of the bag or container.

Warming stored or frozen breast milk

From the fridge

It’s safe to use breast milk stored in the fridge without re-warming it, and some babies can drink cold milk happily. However, others prefer it warmed to body temperature.

Use a pan of hot water to heat up the bottle, or run it under a warm tap. Never use a microwave to do this: this can decrease the quality of the milk, and the uneven heating can create “hot spots” that could burn your baby.

Test the temperature of the warmed milk by squirting a little on your wrist before giving it to your baby. If it stings at all, let it cool first. If there are leftovers after feeding, just throw them away. Once your baby’s mouth has touched a bottle of it, it’s not safe to use the breast milk inside again.

From the freezer

Frozen breast milk needs to be thawed out again. It might look a little different from fresh milk when it thaws, but it’s still good for your baby, and better than formula. Leave it to defrost in the fridge, and then use it straight away.

Never use a microwave to thaw breast milk: the uneven heating could burn your baby. If there are leftovers after a feeding, just throw them away. It’s not safe to put thawed breast milk back in the freezer again.

What if my baby won’t drink stored breast milk?

woman question
If you’ve been exclusively breastfeeding, it might take your baby a little while to get used to stored milk – which can be frustrating after all the trouble you’ve taken to pump and store it correctly!

If your baby is fussing about drinking breast milk from a bottle, it may be helping to warm the nipple of the bottle until it’s closer to your body temperature using warm, sterilized water. This might help your baby realize they’re still getting the good stuff from Mama after all.

Learning how to store breast milk is a great skill for busy moms

mother mom kid child baby milk bottle
Learning how to store and use your expressed breast milk can help you fit the benefits of breastfeeding into a busy lifestyle. This allows your baby to enjoy many of the benefits of breast milk, as even thawed or refrigerated breast milk is a healthier choice for babies than formula.

Talk to your midwife or pediatrician if you need advice on how to store breast milk safely and want to ensure your baby is getting the high-quality nutrition they need.