There are a few basic concepts for storing breastmilk that are important to remember to protect the integrity of the milk and avoid any possible bacterial growth and exposure.
Room Temperature: 4-Hour Window
When you have freshly pumped or expressed milk, it is safe at room temperature for up to 4 hours.
You can safely leave the pumped milk out on the counter for the next 4 hours before transferring it to the fridge. This is convenient if you’re pumping and planning to feed the baby soon, as it doesn’t need warming or cooling if feeding is imminent. You can simply pump the milk, place in a bottle and within that 4-hour timeframe, feed it to the baby without any further steps.
When you have previously pumped or expressed milk in the fridge, it remains “good” for up to 4 days before requiring transfer to the freezer. I suggest labeling the milk with the date and time of pumping before refrigeration, as it’s easy to forget over time. You can also mix milk from multiple days together before freezing to consolidate it; it doesn’t have to be from the same day.
Refrigerator Storage: Up to 4 Days
When you have newly pumped milk that you want to add to previously pumped milk in the fridge it is important that we do not mix different temperatures of milk. So, what you will want to do is to take the freshly pumped milk, put it in the fridge to cool, once the milk is cool, you can add it to the already cool previously pumped milk. Mix cold and cold and warm and warm. The thing you want to remember is that fresh milk can be mixed with fresh milk. Cool milk should be mixed with cool milk. Avoid mixing warm and cool milk together as it can increase the risk for bacteria growth.
Freezer Storage: 6-12 Months
People consider frozen milk good for 6-12 months. When storing it, it’s best to keep it in a deep freezer, but you can also store it in a combo fridge freezer like the one you have at home.
It’s best to keep the milk in the far back of the freezer because that’s where the temperature is most consistent, and the freezer is coldest. Make sure that before placing milk in the fridge, that you date the bag as well as write how much is present in the bag. In terms of thawing previously frozen milk, once the milk is taken out of the freezer and thawed completely, it must be used within 24 hours.
In Summary
Simply put, milk is good at room temperature for 4 hours, fridge for 4 days, and freezer for 6-12 months! Happy storing! If you have any further questions about how to store milk, please contact your IBCLC.
