How to Tell if Breast Milk is Bad

There are so many firsts when it comes to new mamahood. Knowing how to tell if breast milk is bad is one of them. We’ll take you through the details.
While it can be a total game-changer in your life, pumping can be hard work.

And the thought of that work going to waste may be more than a little frustrating.

Knowing how to tell if breast milk is bad is great knowledge to be armed with on this journey.

We’ll take you through the details.

And before we get going, know that breastfeeding comes with a learning curve.

And pumping has its own set of challenges.

If you need support, reach out to your healthcare provider.

They may recommend a lactation specialist who can help you figure out your path.

You don’t have to do it alone.

In this article: 📝

Signs breast milk is bad
How do I know if my breast milk went bad?
What happens if a baby drinks spoiled breast milk?

Signs breast milk is bad

When you start expressing, pumping, and storing your breast milk, you may find that it looks, tastes, or smells different from what you expect.

And this can make you think twice about giving it to your baby.

Here’s what you could notice:

Odor. While breast milk often has a neutral smell, there are times when this isn’t the case. According to La Leche League International, pumped or expressed milk could have a scent that has been described as “soapy,” “metallic,” “fishy,” or “rancid.”
Taste. Breast milk comes in all sorts of flavors, a lot of which have to do with what you eat. This study, for example, showed that mamas who have bitter foods in their diets might pass their palate on to their babies. In some cases, breast milk can taste sour or “off.”
Sight. Breast milk comes in all different colors. The first milk you produce, colostrum, is usually golden, progressing to mature whiter milk. If breast milk is left at room temperature or in the refrigerator, it can separate into layers. But this doesn’t necessarily mean it’s gone bad. So, what does spoiled breast milk look like? If it remains separated or chunky after you try to mix it, it may signal that it has spoiled.

But just because breast milk tastes, looks, or smells different, it doesn’t always mean it’s bad for your little one. Breast milk is quite hardy, and is quite good at being stored for later.

And if there is a distinct change in smell, taste, or sight that you’re worried about, there are solutions to be found!

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How do I know if my breast milk went bad?

Breast milk could appear bad for one of these possible reasons:

1. High lipase content

Lipase is an enzyme that occurs in breastmilk.

It has an important job to do — break down the fats in breast milk so that your baby can more easily get all the nutrients they require from this miracle liquid.

These enzymes even help protect your little one from bacteria, viruses, and parasites.

If there’s significantly high lipase activity in your milk, it can result in a soapy or fishy smell.

And it may not taste too good for your baby.

But here’s the thing!

If your milk does have high lipase content, there’s nothing wrong with you or your milk.

It’s safe for your baby and is still nutritious.

The only catch is that you might have one tiny (tough) customer on your hands.

And they may not be that keen on drinking it up.

But there’s hope.

You could try mixing it with freshly expressed milk, which can help dilute any tastes that are putting your baby off.

It can also help to heat it over a low heat on the stove. (Just avoid the microwave.)

You can then cool it quickly by placing the sealed container in a larger bowl of ice water.

2. Chemical oxidation

If your milk has a sour or rancid smell, it may have to do with something called chemical oxidation.

Basically, this means that a reaction has taken place to change the chemical makeup of your milk.

And it can make it harmful to your baby.

Chemical oxidation could be because of anything from bad drinking water, to the presence of specific fatty acids in your diet, to the milk freezing process.

Because there are a few different possibilities here, it’s a good idea to talk through your unique situation with your healthcare provider.

They may recommend avoiding tap water, cutting back on certain fats in your diet, or changing your milk freezing process.

3. Pumping issues

If the parts of your breast pump are not cleaned properly, it could result in bacterial contamination.

To pump safely, wash your hands before using your pump, and clean the parts after every use.

4. Storage issues

To ensure that your milk is ready for use later, seal it in a bottle or collection bag and place it in the refrigerator or freezer soon after you have done so.

The CDC offers these guidelines on the safe storage of breast milk:

Freshly expressed or pumped milk:

Room temperature: Use within four hours.
Refrigerated at a maximum temperature of 40°F (4°C): Use within four days.
Frozen at 0°F (-18°C) or colder: Preferably use it within six months, but can use within twelve.

Previously frozen milk:

Room temperature: Use within one to two hours.
Refrigerated at a maximum temperature of 40° F (4° C): Use within a day.
Never refreeze thawed breast milk.

Milk from a previous feed

Use it within two hours.

What happens if a baby drinks spoiled breast milk?

Contaminated milk can double your baby’s risk of developing infections that can cause diarrhea.

But that doesn’t mean you should shy away from breastfeeding, particularly for the first six months of your baby’s life.

The health benefits of breastfeeding are so significant that experts all agree that it’s a great choice for you and your baby.

If you’re using donor milk, it’s important to get it through your healthcare provider to ensure that it’s safe.

Beyond everything, be kind to yourself.

This journey is not always plain sailing.

Trust yourself.

Reach out if you need help.

And check in with your Peanut community if you’re looking for support.

We don’t have to do this alone.