If you’re planning on expressing breastmilk then you’ll need to know how, where and for how long you can store it and then how to de-frost and reheat to safely give your expressed breastmilk to your baby. Below an update of the current guidelines.

Storing expressed breastmilk

After pumping your expressed breastmilk you can choose to store in either sterile freezer bags of storage pots. Freezer bags are single use whilst storage pots are multi-use but do need to be sterilized between each feed. Storage pots also come in very handy when you start your weaning journey. Be sure when storing any expressed breastmilk that you write the date and time of expression clearly on the container so you know exactly which one to use first. How you choose to store your breastmilk will really depend on how soon you want to use it. If you plan to use it within a few days, then popping it in fridge is likely better than freezing.

You can store your expressed breastmilk in a number of ways:

  • At room temperature (no more than 25C) for up to six hours
  • In a cool box with ice packs for up to 24 hours
  • In a fridge (at 4C or colder) for up to five days, always store at the back of the fridge, where it’s coldest and store away from meat, eggs or uncooked food.
  • In a fridge freezer compartment for two weeks
  • In a freezer (at -18C or lower) for up to six months

If you know you will be returning to work when your baby is still young and you want to continue to offer breastmilk, then try to get into the routine of expressing and storing your breastmilk on a daily basis. This will help to boost your milk supply, and your baby can continue to receive the benefits of your milk even if you’re not together.

You can add freshly expressed milk to breastmilk that’s already in the fridge, provided it has been expressed on the same day and you cool it thoroughly in the fridge first before mixing the two batches. Bear in mind, though, that you can only keep it until the original milk is five days old.

Warming expressed breastmilk

If your milk has been stored for some time, for example in the freezer, you may notice that it separates, this is just the fat content separating from the rest of the milk. This is normal, so just give it a gentle shake to mix it up again. Especially when combination feeding, warming the milk to body temperature is important to make sure baby takes the bottle. You can warm the milk by placing the bottle in the microwave with the Milkymeter which will allow you to safely and easily warm the milk to the same temperature throughout, removing the risk of hot spots and ensuing the milk is the perfect temperature to feed to your baby.

How to freeze expressed breastmilk

If you want to freeze your milk, do it as soon after expressing as possible. Leave a gap at the top of each bottle or bag, as your milk will expand during freezing. If you’re storing milk in bags, watch out for any tears. You may not notice any until you start to thaw the milk. Remember that plastic bags tend to fall over when thawing. You could also freeze very small amounts of milk in an ice cube tray, ideally one with a lid, or you could store the tray inside a sealed freezer bag. These smaller quantities defrost quickly and are ideal if you need some breastmilk to mix with your baby’s food when you start to introduce solid foods.

Frozen breastmilk should ideally be defrosted in the fridge, and can be stored there for 12 hours. Never re-freeze your breastmilk once defrosted and offer to baby on the same day.

You may also want to read my advise on how to introduce a bottle to a breastfed baby and how to have success with combination feeding