Storing Breast Milk

Sawyer Strand

Updated October 22, 2024 22:41

I am trying to store milk for when I return to work. What are the proper ways to store milk?

Great job planning ahead! Make sure your pumping sessions are the most productive by choosing a breast pump that best fits your needs, and ensure the breast flanges fit properly. Just like any other food or beverage, breast milk has to be both handled and stored properly.

Before Pumping

Before pumping, be sure to wash your hands thoroughly and make sure pump parts are clean. Always use new storage bags designed especially for breast milk. Never wash and reuse milk bags.

Storage Guidelines

Freshly Pumped Breast Milk

- Can be left out at room temperature up to four hours
- Can be stored in the refrigerator for up to four days
  - It is normal to see a thick white layer on top. This is the fat in your milk, and it doesn't mean your milk has spoiled. You can mix it back in by gently swirling the milk. It’s always best to gently mix your breast milk rather than shake.

Freezing Breast Milk

- A chest/deep freezer is preferred. If you do not have a chest freezer, store your breast milk toward the back of your refrigerator freezer as far away from the door as possible. This keeps the temperature from changing when you open the freezer door.
  - A chest freezer keeps breast milk properly frozen for up to twelve months.
  - A refrigerator freezer keeps it properly frozen for up to six months.
- After adding breast milk to a storage bag, remove all the air. This will lessen freezer burn and spoiling, and keep the bag from popping open when it is frozen.
- Many moms store their freezer bags laying flat rather than upright, but read your milk storage bag instructions for how your bag is best stored.
- When combining small amounts of milk to freeze, they should be the same temperature. For example, if you pump a small amount in the morning and another small amount in the evening, chill both overnight, then combine in the morning before freezing.

Keep in mind that storing milk in smaller amounts means less waste.

Thawing Breast Milk

You can thaw your breast milk in the fridge for up to 24 hours. Once it is thawed, you can only keep it at room temperature for 1 to 2 hours before it spoils.
It’s better to thaw more than have to dump milk! If your baby does not drink the entire amount you’ve thawed within 2 hours, it’s recommended to toss it or use it for milk baths.
It helps to mark your bag with date, time, and amount of milk. That way you can thaw and use the oldest milk first.
Always warm milk by running it under warm water or placing the bag in a cup of warm water. Never microwave breast milk or place a bag of breast milk in a bottle warmer! Test the temperature of your breast milk before giving to your baby by sprinkling a bit on your wrist. If you’re comfortable, taste-testing can be helpful as well.