How to Store Expressed or Breast Milk

Ideally, milk fed directly from the breast is best. However, direct breast feeding is not always possible, so expressed breast milk that has been correctly stored is the next best option for infants.

Mothers should wash their hands before they express breast milk. Once expressed, breast milk can be stored in a plastic or glass container with an airtight sealed lid, for example, a food storage container or bottle. The container should be dated at the time of collection, and the caregiver should always ensure that the oldest milk is used first. Fresh or refrigerated milk retains beneficial properties and is preferable to breast milk that has been frozen. The milk should be stored in small portions of around 100–300 mL to prevent waste.

Expressed breast milk that is being refrigerated or frozen should be stored in a new container rather than added to previously refrigerated or frozen breast milk. Adding expressed breast milk to frozen milk can cause the milk to thaw and then refreeze, which increases the risk of bacterial growth in the milk.

Containers and feeding equipment should be washed in hot soapy water and then rinsed. If the infant is three months old or younger, the containers and equipment also need to be sterilised. Sterilising equipment and tablets to make sterilising solution are available from supermarkets and pharmacies. The manufacturer’s instructions must be followed carefully. Alternatively, the containers and feeding equipment can be boiled.

In the refrigerator, expressed breast milk needs to be kept towards the back of the main body of the refrigerator where it is thought the temperature is the coolest. The New Zealand Food Safety Authority recommends refrigerators are operated at 0–4oC (NZFSA 2008).

Options for the short-term storage of expressed breast milk include using an insulated cooler bag containing ice packs where refrigeration or freezing is not immediately available (CDC 2007; Jones and Tully 2006). The maximum storage time using this method is 24 hours. Little research has looked specifically at this form of storage. The recommendations include advice that the ice packs should be in contact with the milk containers at all times and there is limited opening of the cooler bag.

Sourced from the NZ Ministry of Health