5 Ways Breast Milk Changes When Stored

How breast milk changes as it’s stored

1. Fat separates ((OK to feed))

As breast milk sits, the fat rises. You may see a thick, creamy layer on top and a thin, milky layer on the bottom. Just swirl or gently shake the bottle to mix the fat back in before a feeding.

2. Color ((OK to feed))

The color of breast milk can change as it’s stored, and that doesn’t necessarily mean it’s gone bad. When the fat separates, the thin layer on the bottom can look a little bluish, and frozen milk can turn more yellow.

3. Soapy smell or taste ((OK to feed))

You might notice that your milk has taken on a soapy or metallic smell. This is caused by the lipase enzyme, which breaks down fat. It mainly happens with frozen milk, but it can also happen with refrigerated milk. 

Even though it is still safe, some babies might refuse to drink it because of the taste. You can either combine the high-lipase milk with fresh milk, or you can scald your milk before storing it. This is done by heating the milk in a pan just to the point where bubbles start to form around the edges (be careful not to boil), then quickly cool it in an ice bath.

4. Quality decreases over time  ((OK to feed))

I hesitated to write this section because I don’t want you to think that there’s anything wrong with building a freezer stash and giving your baby frozen milk. I don’t want you to think that frozen milk loses all of its nutritional value. It doesn’t! Just like any other food, the fresher the milk, the better the quality. ((Just compare fresh food to frozen and you’ll understand what I mean!)) Frozen milk still contains everything your baby needs, and it’s still better than formula. But I wanted to give you all the facts, so you can better plan how to use your freezer stash to preserve the quality as best you can.

The quality of breast milk goes down the longer it’s stored. Fresh milk has the highest quality, followed by refrigerated, and then frozen. Over time, the nutrients in breast milk break down. Different studies have shown that breast milk loses some of its Vitamin C content, fat, protein, calories, antioxidants, and anti-bacterial and protective properties.

So what should you do?

• Make sure you’re labeling your bottles and storage bags with the date expressed.
• Use fresh milk when possible to give your baby the best of the best. And when using stored milk, use the oldest milk first.
• Breast milk is good for up to 4 days in the fridge, but if you don’t think you’ll use it within those 4 days, it’s best to freeze it as soon as possible to preserve the quality.
• Consider donating a portion of your freezer stash if you don’t think you’ll use it within 3-6 months.

5. Bacteria growth ((NOT ok to feed))

If breast milk is stored longer than the recommended times, bacteria can start to grow and multiply. For the recommended breast milk storage times, click here.