High Lipase in Breast Milk (and What to Do About It)
If you’ve ever thawed frozen milk and thought, “why does this smell… soapy?” or if your baby acts like they dont like the taste of your milk… you’ve probably heard the term high lipase. A quick google/tiktok search will have you quickly self-diagnosed with high lipase milk and a laundry list of things you need to do about it.
buttt let’s clear this up because its not that simple.
What is lipase?
Lipase is a normal, helpful enzyme naturally found in breast milk.
Its job is to break down fats over time so your baby can digest milk more easily. That “over time” part matters.
Fresh milk doesn’t usually smell or taste different because the fat hasn’t had time to break down yet.
But once milk is stored, especially frozen and then thawed, lipase continues doing its job, and that can change the smell or taste.
What we used to think
For years, we blamed this on “high lipase,” or excess lipase in a moms milk.
The idea was:
too much lipase → more fat breaks down than typical → milk smells/tastes bad
So the solution became: scald your milk before storing it (more on this later).
What we understand now
Newer understanding suggests:
It’s often not just lipase
It may be oxidation + normal fat breakdown during storage.
Meaning:
your body isn’t “doing something wrong”
and your milk isn’t abnormal
It’s just how some milk changes over time, especially one stored.
The most important thing to figure out is why the smell and taste of the milk has changed, and it may not be related to lipase at all.
Why fresh milk is different
This is why:
baby drinks freshly pumped milk → no issue
baby refuses frozen/thawed milk → tastes different
Because the change happens during storage, not when the milk is first made.
When do you actually need to do something?
Only if:
your baby refuses stored milk, and
you’ve confirmed it’s not a storage or handling issue (its likely not)
If your baby drinks it → you don’t need to fix anything.
What to try before doing anything drastic
If your baby seems unsure about stored milk, a really simple fix is: mix fresh milk with thawed milk
This can:
balance the taste
make it more acceptable to your baby
Often, this is enough without needing extra steps.
What about scalding?
Scalding used to be the go-to recommendation. It’s likely what you’ve heard about before you found this blog post.
Now, it’s more of a last resort, not a first step.
Why the shift?
it adds a lot of extra work
it can reduce some of the beneficial properties of breast milk
and many babies don’t need it at all
But if your baby truly won’t take stored milk in any way, it can still help in some cases. Assuming we know with 100% certainty lipase is the cause of the taste change.
If you choose to scald, here’s how:
Start with freshly pumped milk
Heat in a saucepan on the stove
Watch for small bubbles around the edges (not boiling) about 180°F.
Remove from heat immediately
Cool quickly (ice bath or fridge)
Then store as usual
Any milk that has been frozen before scalding will remain affected, scalding after thawing will not change anything about the lipase within the milk.
The bottom line
Lipase is normal and helpful
Taste changes happen over time with storage
Not all “high lipase” milk is actually a problem
Try mixing fresh + frozen milk first
Scalding is optional—not routinely recommended anymore
If your baby is taking your milk, you’re doing everything right.
If you’re ever feeling unsure or want to talk through what this looks like in your specific situation, I’m always here to help you navigate it with confidence.
You don’t have to figure this out alone
