Why does my freshly pumped breast milk smell weird?

Understanding the Unusual Smell of Freshly Pumped Breast Milk
Breastfeeding is a natural and beautiful process, but many mothers encounter unexpected changes in the smell of their pumped breast milk. If your freshly pumped milk has a strange odor, it can be concerning. Here’s a closer look at the factors that might contribute to this phenomenon.
The Role of Lipase
One of the primary culprits behind the unusual smell of breast milk is lipase, an enzyme naturally present in human milk. Lipase plays a crucial role in breaking down fats, making them easier for babies to digest. However, when breast milk is pumped and stored, especially if it’s refrigerated or frozen, lipase can continue to act on the milk. This enzymatic activity can lead to a soapy or sour smell, which some mothers describe as reminiscent of parmesan cheese or even vomit-like odors.
Storage Conditions Matter
The way breast milk is stored significantly impacts its smell. Freshly pumped milk should ideally be stored in clean, airtight containers. If milk is left out at room temperature for too long or not stored properly in the fridge, it can spoil, leading to a sharp, sour odor similar to that of spoiled cow’s milk . It’s essential to monitor storage times and temperatures to prevent spoilage.
Fresh vs. Spoiled Milk
It’s important to differentiate between milk that has simply developed a strong smell due to lipase activity and milk that has genuinely gone bad. Freshly pumped milk may have a slight soapy smell, which is normal, but if it smells distinctly sour or rancid, it may indicate spoilage. Spoiled milk will have a very unpleasant odor and taste, and it’s crucial to discard it to ensure your baby’s safety.
Tips for Managing Smell Changes
If you find that your breast milk consistently has an off-putting smell, there are a few strategies you can employ:
1. Scalding the Milk: Some mothers choose to scald their milk before storing it. This process involves heating the milk to a temperature just below boiling, which can deactivate lipase and help maintain a more neutral smell.

2. Storage Practices: Ensure that your pumping equipment is thoroughly cleaned and that milk is stored in appropriate conditions. Use airtight containers and label them with dates to keep track of freshness.
3. Taste Test: If you’re unsure about the freshness of your milk, tasting a small amount can help. Fresh milk should taste sweet, while spoiled milk will have a distinctly sour flavor.
Conclusion
While it can be alarming to notice a strange smell in freshly pumped breast milk, understanding the role of lipase and proper storage techniques can help alleviate concerns. If the smell persists or if you suspect spoilage, consulting with a healthcare professional or a lactation consultant can provide further guidance and reassurance. Remember, your health and your baby’s safety are paramount, so don’t hesitate to seek help if needed.

How to tell if milk is high in lipase?

If your milk smells a little soapy, the cause is often milk that is high in lipase activity.

What should fresh milk smell like?

Milk that is fresh enough to drink will have barely any odor. It will generally smell clean and slightly sweet, but will not have a noticeable scent. On the other hand, milk that has gone off has a very noticeable smell. It will have a strong, sour odor that will immediately put you off drinking it.

Does breastmilk lose nutrients when pumped?

According to the CDC (Centers for Disease Control and Prevention), freshly expressed breast milk can be safely kept at room temperature (77°F or colder) for up to 4 hours. Generally, when freshly pumped, breast milk is at its peak regarding nutrients.

How to tell if breast milk is spoiled?

It will also smell bad, much like spoiled cow’s milk. And, like spoiled cow’s milk, breast milk that’s old will taste sour. (It’s fine to taste your breast milk to check!) Always label your pumped milk with a time and date so you can tell how old it is.

How to tell if milk has high lipase?

The most notable signs of high lipase milk are changes in taste and smell. You might notice your milk having a scent or taste similar to metallic, vomit, eggs, soap, or fishy. The appearance of the milk might also change, though this isn’t always the case.

How do I get the milk smell out of my breast pump?

Cleaning your breast pump by hand

1. Use a wash basin & soapy water. Place pump parts in a clean washing bowl or basin that’s used only for washing infant feeding equipment.
2. Scrub items according to the pump kit’s manufacturer’s guidance.
3. Rinse by holding items under running water.
4. Dry.

What is the 120 pumping rule?

The first 12 weeks of your breastfeeding journey requires frequent breastmilk removal, stimulating healthy milk production. Studies show moms who exclusively pump for a minimum of 120 minutes per day can make enough to feed their babies primarily breastmilk.

What should fresh breast milk smell like?

What does it smell like? Most moms say breast milk smells like it tastes — like cows’ milk, but milder and sweeter. Some say their milk sometimes has a “soapy” smell. (Fun fact: That’s due to a high level of lipase, an enzyme that helps break down fats.)

Why does my breast milk smell bad after pumping?

Some mums notice that their expressed milk has an ‘off’ or soapy smell and taste, even when they have handled it cleanly. This can be caused by oxidation following the normal action of enzymes in the milk designed to help the baby digest the milk fats. This problem doesn’t make the milk unsafe.

What is the 5 5 5 rule for breast milk?

Something I recommend to moms is the 5-5-5 rule. Try and use milk within five hours at room temperature, five days in the fridge, and by five months in the freezer.