Breast Milk Storage
Pumping breast milk can be a time-consuming process, and you don't want to lose any of that precious milk once you've taken the time and care to express it. Luckily, there are many ways to store breast milk safely so your baby can reap the benefits of your breast milk when you are not available for breastfeeding your baby.
The best storage containers for breast milk are specially designed breast milk storage bottles or storage bags. You can also use standard glass baby bottles or plastic baby bottles to store breast milk in the refrigerator or freezer if your bottle is freezer safe.
Breast milk storage bottles are made of freezer-safe plastic that are specifically designed to store breast milk in the freezer. They usually have cc measurement markings telling you how much milk is in each bottle. Many breast milk storage bottles come with freezer-grade labels so you can label each bottle with the date you pumped your breast milk. Most breast milk storage bottles can be attached to any breast pump with a universal seal, allowing you to pump directly into the storage bottle. Most breast milk storage bottles are top rack dishwasher safe.
A preferred method of storing breast milk is to use pre-sterilized breast milk storage bags made specifically for the freezer. They are made of freezer-safe, medical grade plastic with a zipper seal to keep your milk sterile and safe. Breast milk storage bags usually have cc measurement markings on the bag showing how many ounces of breast milk are in each bag. They also have an area on the outside so you can note the date and time you pumped your breast milk. This will help you keep track of how long the breast milk has been in the freezer. Always use ink on a breast milk storage bag. Never use a permanent marker to date milk as it can seep through the plastic and contaminate the milk.
If you are using your breast milk soon after pumping, breast milk will last at room temperature for six to eight hours in a bottle or storage bag. If using within the next week, breast milk will last between 3-7 days in the refrigerator. Frozen breast milk will last up to 2 weeks in a freezer compartment inside your refrigerator, 3 months stored in a freezer compartment attached to, but separate from your refrigerator, and up to 6 months stored in a deep freezer. Liquids expand when frozen, so always leave extra room at the top of your breast milk storage bag or bottle to prevent splitting or over-flowing. Always use your oldest breast milk first.
Thaw frozen breast milk in the refrigerator overnight, hold the bottle under warm water, or set the bottle in a pan of warm water for 20 minutes. Do not microwave breast milk. Microwaves can destroy essential vitamins, nutrients, and anti-bodies present in the breast milk and may heat unevenly, creating hot spots.
Do not add freshly pumped milk to frozen breast milk. The new warm milk may thaw the top layer of frozen milk when they come in contact with each other. Thawed milk is safe in the refrigerator for 24 hours, but never re-freeze thawed milk.
Breast milk can vary in color, consistency, and smell, depending on your diet. You may notice the variations more after it has been frozen. It can look slightly blue, yellow, or brown. It is also normal for breast milk to separate into layers. The hind milk or fatty part of the milk rises to the top, the fore milk or watery part of the milk sinks. Swirl the bottle or sealed bag to mix the layers together.
To avoid wasting breast milk, store breast milk in 2-5 ounce portions. Small portions thaw and warm up more quickly, and less milk will need to be thrown away if your baby does not drink it all. You can combine milk from different pump sessions throughout the day, but cool each batch before combining in one breast milk storage container.
- I pumped at work and used the Gerber Seal 'N Go Breast Milk Storage Bags to store and transport my milk. These bags were everything I needed and more. I could write the date and time I expressed on the bag, fill the bag, and throw it in the freezer. The zipper seal never leaked, even when I filled it to capacity. The opening would open so wide I could hand express into the bag and not lose a drop! I used a different brand once when I couldn't find these, and was not as happy. The next time I found the Gerber bags, I bought a few boxes – I recommend you do the same.