How to Store Breast Milk: What You Should Know

It’s perfectly normal to have a lot of questions about breastfeeding if it’s time for you to go back to work. In fact, you have to know how to store breast milk, how to freeze it and how to defrost it.

If you don’t know where to begin, not to worry. After reading this article, you’ll know how to store your breast milk, without losing its amazing properties. Don’t miss any detail!

Before expressing and storing breast milk

First of all, you need to wash your hands with water and soap, whether you do it manually or using a breast pump. However, in case you use a breast pump for expressing your breast milk, make sure it’s clean and dry.

The following are some containers you can use to store your milk:

• Free of bisphenol A, rigid containers, which can be made of plastic or glass. Safe-for-use containers include a symbol with a fork and a glass. This means that you can store food in them. Remember that they must be clean and dry.
• Breast milk storage bags. Nowadays, you can find many types of bags of different brands. They’re also very practical for freezing.
• Urine sample containers aren’t suitable for storing food.

How to store breast milk

Recently expressed breast milk:

• At room temperature (between 66ºF and 71ºF): 6 hours.
• In a cooler bag (59ºF): 24 hours.
• At room temperature, but defrosted milk: 1 hour.

Refrigerated breast milk:

• Refrigerated milk in the fridge: up to 8 days, ideally, up to 5 days.
• Defrosted milk in the fridge: 24 hours.

Frozen breast milk:

• In freezers that are included inside the fridge: 2 weeks.
• In separate freezers that are part of the fridge: between 3 and 4 months.
• In freezers that are totally separated from the fridge: up to 12 months, ideally, up to 6 months.

It’s important to mention that all these times are different in the case of premature babies.

Tips to store breast milk

• You should store small amounts of milk (1.7 oz. to 2 oz.) in the fridge or freezer. This is because you can’t store the remaining milk again.
• Use the refrigerated milk before using the frozen milk.
• Label the containers, writing the date of extraction. This way, you’ll always use the older one. Try to write down the amount of milk in each container, because once you freeze it, there’s no way of knowing the exact amount.
• Try to leave space free of milk in the container, because it expands when frozen.
• Don’t put the container on the fridge door shelves. It’s always better to keep it at the bottom of the refrigerator. This is because, when opening the fridge door, the temperature varies and the milk can go bad.
• If you’re not using the milk you just expressed within the following 4 days, freeze it. As a result, you’ll maintain the milk’s properties.

How to defrost and heat your breast milk

• To defrost the breast milk, you can take it out of the freezer the night before using it, so it defrosts slowly.
• You can also put it under sink water or inside a container with warm water (not on the burner).
• It’s not a good idea to defrost your breast milk in the microwave, because it can get burned. The same can happen if you defrost it on the burner.
• Remember to use the older container from the freezer.
• After defrosting it, stir it for a while before giving it to your baby.

The breast milk has a different aspect

When we store breast milk in a container, it separates into two phases. This is because of the water and the fat it contains.

Before giving it to your baby, you should stir the milk, in order to make it homogeneous. Stir it but don’t shake it. 

The breast milk has a different smell

Sometimes, frozen or defrosted breast milk has a strange smell, like rancid milk. Actually, we may even think it has gone bad. This happens because of the lipase, an enzyme in charge of breaking down fats and releasing milk fatty acids. Some babies don’t care about its taste, while others reject it. If this happens, you have to scald the breast milk.

To do this, you must heat it until tiny bubbles appear at the edge of the pot. Once these bubbles appear, remove the breast milk from the fire and cool it as quickly as you can, then freeze it.

How can you store your breast milk if you express it at work?

If you express your breast milk at work, look for a place to refrigerate it until you get to go home. Then, on the road, keep it inside an ice bucket, so you don’t break the cold chain.

If there’s no refrigerator where you work, you’ll have to keep it inside the ice bucket you take for the road.

In order to prevent it from spilling, put it inside hermetic sealed containers or breast milk storage bags.

We hope you can find many answers to your questions by reading this article. However, if you have more questions or concerns, ask your doctor for more advice.