You’ve done the hard work of pumping and storing your breast milk. Now you’re wondering how to thaw frozen breast milk and prepare it safely for your baby.

Your freezer is more than just a place to store meals for when you’re too tired to cook. It’s also a place to store your precious liquid gold.

Pumping, freezing, and bottle feeding solve common breastfeeding challenges like bad latches, tongue ties, inverted nipples, and leaky boobs. They also enable you to share feeding responsibilities with your partner or another caretaker if you can’t be with your baby around the clock. 

But what do you do when you take that bag of icy cold breast milk out of the freezer?

Read on to learn how to thaw your breast milk and prepare it safely for your little one.

How to thaw breast milk

Thawing breast milk can be a relatively effortless part of your daily routine. Depending on your needs, you can choose from a few different methods. In this blog, we’ll answer common questions so you can feel confident you’re thawing your breast milk according to safety guidelines. 

How long does frozen breast milk keep?

Frozen breast milk has some serious staying power. However, breast milk does expire, so it’s essential to understand how to evaluate whether your breast milk is safe to thaw and use. 

Shelf life varies depending on your freezer type:

Do you have a deep freezer? If so, you can safely freeze frozen breast milk for up to 12 months. Be sure to place your breast milk near the back of the freezer to avoid exposing it to room temperature air. 

Do you have a standard freezer? If so, your frozen breast milk will last up to six months. Store the breast milk toward the back of the freezer to ensure the coldest temperature.

Additionally, be sure to follow safety storage guidelines when freezing your breast milk:

• Use breast milk storage bags, glass bottles, or plastic bottles with no BPA.
• Freeze breast milk in two- to four-ounce portions (roughly one feeding size to reduce breast milk waste).
• Mark the date on each container when you put it in the freezer.
• Thaw your oldest milk first. 

How do you defrost breast milk quickly (and safely)?

For busy moms and dads, quick and easy is the name of the game. So when you’re ready to use your frozen breast milk, choose from a few safe defrosting methods:

• Put your frozen breast milk in the refrigerator overnight to thaw for 12 hours. (You could do this every evening at 6 pm to have enough defrosted milk for the next day.)
• Thaw a sealed bottle or bag of frozen breast milk by holding it under warm or lukewarm running water. (This is perfect for single, on-the-go feedings when all you have is a sink.)
• Thaw a sealed bottle or bag of frozen breast milk by placing it in a bowl of warm or lukewarm water. 

Avoid thawing your breast milk by putting it in the microwave. Not only can microwaves deplete nutrients, but they can also create hot spots that burn your baby’s mouth.

How long does breast milk last after it's defrosted?

Once you defrost your breast milk, you need to use it fairly quickly:

• If you put your frozen breast milk in the refrigerator to thaw, use it within 24 hours. 
• If you use warm or lukewarm water to thaw your milk, feed it to your baby within two hours. 

Dispose of any milk you don’t use within the designated “safe” time period. Trust us: we understand throwing breast milk away can be upsetting, but your baby’s safety comes first.

Tip: If your babysitter, daycare provider, or family member will feed your baby, write down thawing instructions so your caregiver knows what to do.

How to prepare breast milk

Once you’ve defrosted your frozen breast milk, it’s time to prepare it. Like thawing, it’s important to know your options and safety guidelines. We’ll answer some common questions below.

Is it safe for babies to drink cold breast milk?

Yes! Your baby can safely enjoy cold breast milk. However, some babies prefer warm milk, which is why many dads, moms and caregivers choose to heat cold milk.

But if your baby tolerates cold breast milk, your meal prep will be quicker.

How do you warm up breast milk from the refrigerator?

If your breast milk is in your refrigerator, you can heat it using a bottle warmer or simply by placing the sealed container in a bowl of warm water. (Large coffee mugs work well too.) 

Avoid heating cold breast milk on the stovetop or in the microwave as both can deplete vital nutrients and burn your baby’s mouth.

How do you warm up breast milk in the bottle on the go?

Busy moms don’t want to lug around a bottle warmer – and you definitely don’t need fancy equipment to warm up a bottle of breast milk. 

Use a soft-sided cooler, some ice packs, and glass or BPA-free plastic bottles to transport your thawed milk. When it’s time for a feeding, run the bottle under warm water. Sprinkle a few drops on the inside of your wrist to check the temperature and ensure it’s not too hot.

Is it safe to warm breast milk more than once?

No. After warming up breast milk, you must use it within two hours. If your baby doesn’t finish the warmed milk, pour the remainder out. Don’t risk milk quality or your baby’s safety by reheating it.

Tip: If your babysitter, daycare provider, or family member will feed your baby, write down preparation instructions, so your caregiver knows what to do.

The best tip for how to prepare breast milk

You have many considerations to make when pumping, storing, thawing, and preparing your breast milk. 

Hand expression or breast pump? Storage bags or bottles? Glass bottles or plastic bottles? Bottle warmer or tap water? 

You can’t go wrong if you follow safety guidelines. The best tip is to relax and know you’re feeding your baby nutritious food in the way that works best for your family. 

When in doubt, always contact your pediatrician or a lactation consultant for help.