Storing mother's milk correctly

It's not always possible to breastfeed your baby. But you can express breast milk in advance, and then your child can enjoy it from a bottle wherever you happen to be – in a restaurant, on the tram or in the park. However, correct and safe storage is vitally important if the milk is to remain safe for consumption.

Breast milk is precious, because it's the best nutrition for babies. The tips below will help you preserve all the important nutritional benefits of the milk once it is expressed and also minimise the risk of bacterial contamination:

  • Store the expressed milk in clean (i.e. sterilised) plastic or glass containers or in "Pump and Save" bottles. Stainless steel containers, normal freezer bags, or yoghurt pots should not be used.
  • Ideally you should express directly into the container that you want to store the milk in. That way the milk will come into contact with fewer germs and bacteria than if it is poured from one container to another.
  • Only fill the container three quarters full, so that the milk has room to expand as it freezes.
  • Freeze the milk in small portions of 60 ml to 120 ml. These will defrost quickly, and there will be less waste if the baby doesn't drink all the milk. Defrosted milk must not be refrozen and should be disposed of if not used.
  • Label the milk containers with the date on which you expressed the milk.
  • Always defrost the milk with the oldest date as breast milk doesn't have a long storage life.
  • Freshly expressed milk can be added directly to frozen milk as long as it has been cooled first. In addition, the top layer of the frozen milk must not have thawed
  • Breast milk goes off easily and should therefore be stored in the coolest part of the fridge, on the middle shelf.
  • Medela recommends the following guidelines for storage times:
    - Freezer: 6 to 12 months at -20°C to -18°C
    - Fridge: 3 to 8 days at 4°C or less
    - Room temperature: 4 to 6 hours at 19°C to 26°C
    - Defrosted milk may be kept in the fridge for a maximum of 10 hours. Defrosted milk must not be refrozen.


If you have any questions about feeding and caring for your baby, SWICA customers can contact the santé24 telemedicine service free of charge on +41 44 404 86 86. A telemedicine practice licence allows santé24 physicians to provide additional medical services in cases that are suited to a telemedicine approach. SWICA customers can also use the BENECURA medical app to carry out a digital SymptomCheck and receive recommendations about what to do next. During a subsequent phone call with santé24, customers can decide for themselves whether to release their information from SymptomCheck to santé24.