When Your Breast Milk Smells Weird

Jenna had been nursing her baby boy for four months. Things were going well. They had a rocky start- he was born 4 weeks early and was jaundiced and sleepy at the breast. Extra help from a lactation consultant and lots of pumping to build supply and they made it. Now, he’s four months old and Jenna had been working on building a freezer stash so her and her hubby could go for a night away. She was doing a test run to ensure he would take a bottle– she took the milk from the freezer, unthawed it in a container of warm water, glancing proudly at her freezer full of milk.
She poured the thawed milk into the bottle and stopped in her tracks. What was that smell? Why did her liquid gold smell rancid, almost soapy? She quickly thawed another bag only to smell the same thing! Panic set in as she realises her entire lot of breastmilk is ruined.
This is actually more common than we think. There are moms who have replaced entire deep freezes, sure that it was the reason their milk spoiled… only to have it smell the exact same way again.

So why does this happen?

Lipase. Lipase is an enzyme which is normally found in breastmilk. Lipase acts as an emulsifier breaking down fat, so fat-soluble nutrients are available to baby. Some women naturally produce more lipase than others. High concentration of lipase means fat breaks down faster, altering the taste and smell of the milk. Milk with high lipase is safe for your baby to consume, although some will refuse to drink it. It is important to note this only happens when your milk is pumped and sits at room temperature, in the fridge or is put in the freezer. Straight from your breast does not alter the taste at all.

How can you avoid lipase issues?

Pump and give the milk right away.

The longer the milk sits, the more the fat will break down, causing the odor. If you are going out- pump right before you go (and feed your baby). The less time it sits before your baby drinks it, the less likely it will taste sour.

Scald the milk

Right after pumping, scald your breast milk. This will help break down the lipase, keeping the composition of your breastmilk, and saving the smell. Do not boil your milk, just heat until it reaches 82 degrees Celsius. You will notice small bubbles on the sides of the pot. When it has reached temperature, cool and pour into freezer safe breastmilk bags and freeze.

Don’t throw out the smelly milk!

Once you discover your milk has lipase, don’t throw it all out. Often your baby will take it mixed in with solids.
Breastmilk also has many other uses- put it on your baby’s bum rash, dry skin and even eczema. Place it directly onto her skin or mix it into her bath water.

I had high lipase with my first baby, will it happen with the next?

Potentially. Many moms report that they do have it again with the next baby. Pump and freeze your milk earlier with the next baby and see what happens. You may still notice the soapy smell, but baby number #2 may not mind the taste. Remember it is safe for your baby to drink, so if she will, awesome!