High Lipase Milk: Cause, Effects, and How to Manage

Lipase is an important enzyme that helps your baby break down breast milk so that they can digest and absorb the essential nutrients contained in it.

Everyone produces lipase. This enzyme is normally produced in the pancreas but has also been found in the digestive tract of newborn babies. For people of all ages, lipase works in the intestines to help break down fats.

Lipase is naturally found in breast milk, and it’s believed that an excess of this enzyme can cause the flavor of breast milk to change. When expressed milk is stored in cool temperatures, it’s suspected that high levels of lipase make the fats in your milk break down more quickly, impacting the flavor and smell.

Recent research has shown that not all sour-smelling milk results from lipase activity. In fact, in some cases, sour-smelling milk had lower levels of lipase.

So, before assuming you have high lipase milk, check to be sure your breast pump parts and storage containers are clean and dry, decrease your consumption of rancid-smelling fats like fish oils, and ensure that your milk is being refrigerated soon after pumping.

If you suspect that higher lipase levels are the culprit of a weird flavor, there’s a simple home test you can perform.

After expressing some milk, store it — following recommended guidelines — either in the freezer or refrigerator. Let it sit for a day or two and then check the odor. If the milk originally smelled fine when you first pumped and now smells soapy, there’s a good chance that you might be producing breast milk with a higher lipase content.

The quick answer is, none. There is no evidence that high lipase milk is bad for your baby or that it will create problems in the future.

Your baby is capable of digesting this milk without any issues. Remember, this is the same milk that your baby is drinking if they nurse directly from the breast. It’s the pumping and storing process that makes the milk seem different.

The only issue that comes into play is that not all babies will appreciate drinking stored milk with a new flavor or smell. Some babies may not be affected at all. If your baby is rejecting stored, expressed breast milk, you’ll want to find a solution to eliminate the offending flavor.

The true cause of the sour smell and taste isn’t necessarily the amount of lipase in your milk, but the rate of lipase activity. While some moms can store milk in the refrigerator or freezer for a while with no change in smell, others notice a change after just 24 hours. It’s assumed that’s because the fat breakdown is happening at a faster rate, which causes the milk to smell sooner.

Also, let’s make it clear that having milk with high lipase activity isn’t a sign that there’s anything wrong with you. You’re not a failure, nor does this mean that there’s anything physically wrong.

The “my milk tastes soapy” issue is incredibly common. So, don’t let this hiccup in your breastfeeding journey be one more unnecessary item you use to measure your worth as a mother!

But still, if you’re a breastfeeding mom who’s planning to go back to work or just wants to take an occasional much-needed break — and your baby is refusing to drink your stored, high-lipase milk — then you’re going to need a solution to the problem.

If you plan to use stored milk, there are a few methods for eliminating the flavor and smell issue caused by high lipase activity.

Track your timing

The flavor of high lipase milk can change as quickly as 24 hours or over a few days. One option is to test through trial and error exactly how long it takes before the flavor changes. Knowing this, you can still pump and store milk.

If, for example, you realize that it takes four days for your milk to change its flavor, then that means that from the moment you pumped it, you have four days to use this milk before the flavor turns and your baby won’t accept it.

If you’re a working mom who pumps at the office to make an extra supply for the next day, this approach may work for you since you’ll be able to use the extra milk fairly quickly. But if you’re pumping extra milk and don’t plan to use it within a day or two, this approach won’t get to the root of the problem.

Adjust the pump

According to the text Breastfeeding: A Guide for the Medical Professional, some mothers found the smell of their stored milk improved when they lowered the pressure and speed of the breast pump. Researchers also noted the same result in bovine literature.

Mix it with freshly pumped milk or other foods

Combining soapy-smelling refrigerated milk with freshly pumped milk can sometimes sweeten the flavor again.

Mixing stored milk with solid foods is only an option if your baby is already old enough to begin eating solids. But sometimes, masking the flavor of high lipase milk can trick your baby into eating it and save you the heartache of having to throw out that hard-earned liquid gold. Baby cereals, oatmeal, and smoothies are great options for this trick.

Scald the milk

You might feel overwhelmed at the thought of having to add another step to your expressing process. But if the alternative is a baby who refuses any of your pumped milk, scalding the milk might be the best option to store your milk for longer periods.

Scalding should be done to your freshly expressed milk prior to storing it. To scald milk, the goal is to heat it to where bubbles form but to avoid boiling it. If you heat the milk for too long and it boils, you can destroy the nutrients. Look for bubbles to begin forming around the edges of the pan or bottle and remove the milk from the heat.

You’ll then need to quickly cool it in an ice bath to safely reduce the temperature before storing. Be sure to store it following the recommended guidelines for the proper temperature — whether you’re placing it in the refrigerator or freezer.

Most experts agree that scalding breast milk in a pan is best, but you can use a bottle warmer. Just ensure that the warmer doesn’t heat the milk above 180 degrees Fahrenheit.

Foul-smelling milk can feel like a devastating blow — especially if your breastfeeding journey hasn’t been the easiest. But the truth is that you’re not alone and this is a situation that can be managed.

Whether you opt for adjusting the pump, masking the flavor, or scalding the milk, know that there is a solution to ensure that your little one is getting all of the possible nutrition from your stored breast milk.