February 05, 2019 4 min read

As a mom I wanted to make sure my baby kept having breastmilk while I was away from him, as such it became very important to know how to correctly store freshly expressed milk. A quick search on Google proved overwhelming with so many opinions and instructions – how do you know which one is right and if you are storing your milk correctly?


There are a few factors that have an impact how we store and keep our milk safe for our baby’s consumption. Various factors such as milk volume, room temperature when milk is expressed, temperature fluctuations in the refrigerator and freezer and cleanliness of the environment can affect how long human milk can be stored safely.

Please note this guideline is for home storage for a healthy full-term baby only. For a hospital setting please chat to your local medical practitioner.


Before expressing:

  • Make sure your pump is always clean and sterilized before pumping.
  • Bottles for your milk storage need to be clean, sterilized and ready for use.
  • Wash your hands well



Room temperature

Many international sites say that breastmilk can be kept at room temperature for anything from 3 – 6 hours. I really would not recommend leaving breastmilk at our South African “room temperature” for very long.  Remember when reading international sites, the “normal” room temperature is often quite a bit lower than the temperatures we experience at the southern tip of Africa. I, personally, would not leave breastmilk out of a cooled environment for longer than an hour.


Cooler bag:


  • If you are using a cooler bag, please make sure that you have frozen ice bricks to keep the milk cool. Medela has a lovely cooler bag with a specially designed ice brick that fits 4 Medela bottles keeping your milk cool and well insulated.
  • Remember to not leave you cooler bag in direct hot sunlight.
  • Should you use the right cooler bag and frozen bricks – breastmilk will be safe in this environment for 10 – 15 hours.



  • Milk should always be kept near the back of the fridge, if you place the milk in the door of the fridge the temperature will keep changing as the hot air enters the fridge when opened.
  • Fresh milk – can be kept in the fridge for 3 – 6 days. If milk is going to be stored for longer, try freeze the milk as soon as possible.
  • Thawed milk (this is breast milk that has been previously frozen) – this milk can only be kept in the fridge for 24 hours in total. It must be consumed in this time.


The cream will rise to the top of the breastmilk during storage. Gently swirl milk (do not shake) to mix before checking temperature and offering to baby.


If you have not expressed enough for one feeding session in one of your pumping sessions, milk from different pumping sessions/days may be combined in one container.



  • Milk needs to be at the SAME temperature for you to be able to combine it.
  • Keep both bottles of smaller amounts in the fridge until they are the same temperature before you mix the milk in one container.
  • If you are going to freeze this combined milk, make sure to use the suggested timelines from the date of the first milk that was expressed.




  • If you have a combined fridge with the little freezer compartment inside your fridge – Milk will stay safely frozen for 2 weeks
  • In a self-contained freezer and fridge unit – milk will stay safely frozen for 6 months
  • In a standalone chest freezer - milk will stay safely frozen for 6 - 12 months. However ideally use this within 6 months.


How to thaw frozen milk:

  • Thaw slowly in the refrigerator (this takes about 12 hours – try putting it in the fridge the night before you need it).
  • Avoid letting milk sit out at room temperature to thaw.
  • For quicker thawing, hold container under running water - start cool and gradually increase temperature.
  • Previously frozen milk may be kept in the refrigerator for up to 24 hours after it has finished thawing.


How to warm breastmilk:

  • Heat water in a cup or other small container, then place cold milk in the water to warm
  • Use a bottle warmer.
  • NEVER microwave breastmilk
  • NEVER heat breastmilk directly on the stove.
  • Once breast milk is brought to room temperature or warmed after storing in the fridge or freezer, it should be used within 2 hours
  • If baby does not finish milk at one feeding, it is probably safe to refrigerate and offer within 1-2 hours before it is discarded.



How to store your milk:

  • To avoid waste and for easier thawing & warming, store milk in smaller quantities, we suggest anything between 60 – 120ml portions.
  • Use breast milk storage bags or clean food-grade containers with tight fitting lids made of glass to store expressed breast milk.
  • Never store breast milk in disposable bottle liners or plastic bags that are not intended for storing breast milk.
  • Clearly label the breast milk with the date it was expressed.
  • If you will be delivering breastmilk to a childcare provider, clearly label the container with the child’s name and talk to your childcare provider about other requirements they might have for labeling and storing breast milk.

I trust the above provides you with some valuable information with regards to looking after your liquid gold.


Much Love

Natalie aka Mrs Milk