High Lipase In Breastmilk: A Complete Guide & the Best Scalding Method EVER

Jun 13, 2022Breastfeeding, New Moms

This article may contain affiliate links, and we may earn a small commission when you click on a purchase link. There’s no extra cost to you, and we sincerely appreciate your support! You can read our full disclaimer policy here.

Get 25% off Willow 3.0 for Everyday Heroes. Valid from January 26, 2023-February 7, 2023.

High Lipase In Breastmilk: A Complete Guide & the Best Scalding Method EVER

Nearly two gallons of breastmilk. 210 ounces to be exact. That’s how much milk I pumped and froze before I realized my daughter wouldn’t drink a single drop of it.

Lots of internet searching and research later, I finally pinpointed the source of my frustrations: high lipase levels in my breastmilk. Turns out that if my breastmilk wasn’t promptly scalded after pumping, the fat in it would start breaking down more quickly than normal, causing my milk to take on a sour or soapy smell and taste

milk storage - lansinoh bags with willow pump

The soapy-smelling breastmilk is not harmful, and it has no effect on the quality of the milk. But if your baby doesn’t like the taste of it? You’re out of luck.

I don’t know how many women deal with high levels of lipase in their breastmilk, but I do know I’m not the only one.

After three children, I’ve finally figured out the best way to efficiently scald my milk, and I have some tips and tricks to share with you.

Plus, the method I’ve perfected, sous vide, is not explained or detailed anywhere that I’m aware of. I sincerely hope this helps another mom out there learning how to deal with this pesky enzyme!

sous vide machine is now circulating the water
Sous vide

Also, I don’t know if I need to say this, but I will: I am not a doctor or a physician. I’m writing this article as a regular mom who has high levels of lipase in my breastmilk. All the information in this article is provided for informational purposes only and does not intend to substitute professional medical advice, diagnosis, or treatment.

Table of contents:

What Is High Lipase in Breastmilk?

If you’re reading this, you probably already know what high lipase in breastmilk is, or at least its effect.

High levels of lipase in breastmilk cause the milk to quickly turn sour, soapy, or metallic, both in smell and taste. That soapy flavor is caused by high lipase levels, a naturally-present enzyme that breaks down fat.

All breastmilk has lipase – it’s actually essential for helping newborn tummies properly digest and break down the fat in the milk.

However, when there are higher-than-normal lipase levels in your milk, those enzymes break down the fat a lot faster than normal, causing the milk to take on a sour, soapy, or metallic flavor.

Again, the milk is still completely safe to consume and is not damaged or rancid. It just has a less pleasant taste that causes many babies to turn up their noses.

willow milk bags are horribly shaped for freezer storage

How Do I Get Rid of High Lipase In Breastmilk?

The only way to get rid of high lipase levels in breastmilk – and stop that off-smell and taste from developing – is to scald it. 

Lipase can be destroyed at high temperatures, so you’ll need to heat your milk to preserve it. I’ll share all my tips and tricks later in this article.

What Can I Do with Soapy or Sour Breastmilk?

Chances are, you won’t realize your milk has gone sour or soapy until you’ve started stocking your freezer with it. I started pumping right away after having my first baby, and I was nearly two gallons in before I realized my milk had high levels of lipase in it. 

For any other moms out there who fight for every single ounce, losing 210 ounces of breastmilk was absolutely devastating for me.

I was completely gutted when we put two and two together, but don’t panic. There are a few things you can do with soapy or sour breastmilk, so don’t toss it!

  1. See if your baby will tolerate it. While the milk may smell off, it’s perfectly safe and still includes all of the important nutrients for your baby. If your baby doesn’t mind the taste, you’re clear to use it like normal. My children, however, had no interest in the soapy flavor. In that case, there are a few more options…
  2. Mix your high-lipase milk with freshly pumped milk. This would never have worked for me, logistically, but if you’re in a place where you can mix half freshly pumped milk with half-frozen milk, it can dilute the off-flavors. Your baby may accept it.
feeding baby a bottle
A family friend bottle-feeding our second child scalded milk while we were on a date
  1. Use the high-lipase milk in baby food purées and baby oatmeal. Adding the off-tasting milk to baby oatmeal or certain purées that need to be thinned out can be a wonderful solution. The food and oatmeal flavor helps mask the soapy taste of the milk. It’s certainly worth a test and can put your pumped milk to good use. I was able to use some of my previously pumped milk in homemade food purées like sweet potatoes to help thin it out for my baby, and she did not refuse it.
  2. Donate your milk. Last but not least, consider donating your milk. Milk banks do not care if your milk has high levels of lipase in it. When I called my local milk bank, they immediately knew what high lipase was (many doctors had never even heard of it, so that was a relief). They didn’t care at all and were glad to accept all of my frozen milk. They tube feed this milk to preemies in the NICU, so those babies don’t taste the milk anyway! Donating all of that milk gave me so much peace that my hours and hours of hard work was being put to good use. I even got emails when my milk was used in Florida hospitals, which was amazing!
milk bank letting me know my milk was donated

Why Does My Doctor Know Nothing About Lipase and Breastmilk?

The most frustrating part of my journey with high lipase levels in my breastmilk is that no one knows anything about it!

Two pediatricians, three OB-GYNs, and my primary care doctor have never heard of high lipase levels in breastmilk. The only physician who had any insight was a lactation consultant (God bless lactation consultants), but even I had a deeper knowledge of the topic than she, just from my online research.

It’s honestly so frustrating when a doctor looks at you like you’re crazy and then comes back with advice that’s copied and pasted from a Google article you’ve already read top to bottom.

My only assumption at this point is that the topic of high lipase levels in breastmilk is so rare that it’s not taught in medical school, and perhaps it doesn’t come up in office visits often enough.

milk in freezer

Why Do I Have High Lipase Levels In My Breastmilk?

The question that plagues me is: why do I have high lipase levels in my breastmilk? I’ve searched everywhere for this and have asked every doctor that will listen.

No one knows for certain, though a lactation consultant suggested it may be related to your gut health. I have never gotten any testing to prove or disprove this theory. I asked my OB, who said he wouldn’t pursue any gut health testing because he had no professional knowledge on this topic.

I also have had full bloodwork done on everything from my liver enzymes to my vitamin levels, and everything is completely normal (save for being sightly low on vitamin B12 and vitamin D).

After my primary care doctor researched it, he basically said he believes it’s all genetic and there’s nothing you can do to lower your lipase levels.

weighing milk from willow go pump

I personally cut out dairy when my babies are 0-2 months (all my babies have been sensitive to dairy at first). Removing dairy from my diet has had no impact on the lipase levels in my breastmilk.

So, I’m sorry to say: no one really knows why we have high lipase levels in our breastmilk. Our best course of action is to learn to live with it, find ways to efficiently scald our milk, and make it work!

Do High Lipase Levels Go Away?

I thought the high lipase levels in my milk might’ve been a problem with my first child but perhaps not with my second. Nope! I was wrong. 

It seems that high lipase levels are for life, so don’t make the mistake I did and start freezing breastmilk without scalding, assuming you’re home free.

Lansinoh milk storage bags
With our second child, I only scalded the milk when I had extra time. I wasn’t sure if I needed to scald it anymore, but I labeled the bags that I did not scald. Turns out all these bags were no good in the end.

How to Scald High-Lipase Breastmilk (3 Ways)

I’ve had three children and have tried every method under the sun for scalding breastmilk. I have the luxury of working from home, so I do breastfeed my baby almost exclusively, but I still pump every day to build up a freezer supply. 

I personally like having milk in storage for when my husband and I go on dates, if we end up going on a vacation, or if I somehow lose my milk supply. I’m writing this during a huge formula shortage, so it’s nice to know I’d have a little bit of coverage by doing all this pumping.

willow 3.0 with milk in it

I write all this to say that I’m not pumping and scalding in a public location. I imagine things might be a little trickier – and more stressful, no doubt – if you’re pumping, scalding, and storing at work or while traveling.

That said, my favorite method for scalding milk would be ideal in a work environment, I would think. Here we go!

Method #1 (Worst): Scald Milk On the Stove

This method is the one I tried first, and it’s awful in every way. It takes forever, you dirty a pot, and you have to pay close attention to the temperature of your milk the entire time.

You basically pour your milk into a small saucepan, turn the heat to medium, and stir constantly with a thermometer (Thermapen is the BEST) in the milk. The thermometer should never touch the bottom of the pan or you’ll get a false reading.

best saucepan for scalding milk
I used a small saucepan from All-Clad when I scalded my milk over the stove. You want something pretty small that heats evenly, and All-Clad excels in this category.

Once the milk reaches 180 degrees Fahrenheit, you want to pour it out and bring the temperature down as fast as you can over ice. I recommend pouring your scalded milk in a stainless steel baby bottle set over ice and mix the milk until the temperature comes down. Then, pour the cooled milk into a breastmilk storage bag and freeze.

This whole process takes 10-15 minutes and requires you to be physically present the entire time. For many women, it’s just not feasible, especially if you’re doing this many times a day.

Method #2 (Decent): Scald Milk In a Bottle Warmer

The bottle warmer method is the one I used almost exclusively with my son (second child). It’s a thousand times better than the stovetop method, but it does require patience and a little attention.

Pour your pumped milk into a stainless steel bottle. I used this one – it’s great.

Set your bottle warmer to 4-5 minutes and set a thermometer in the bottle. I use and love Thermapen. Stir the milk occasionally to ensure it’s warming through evenly. Once the milk reaches 180 degrees Fahrenheit, remove the bottle (it’ll be hot) and set it in an ice bath to cool.

Stainless steel bottle

If you pump the same amount of milk each time, you can time how long it takes to reach 180 degrees. That allows you to walk away or do other things while it’s heating, though you do need to occasionally stir it.

This is a mostly fuss-free method that’s especially great if you already have a bottle warmer. We had the Dr. Browns warmer, and it worked perfectly for this.

I also think this is totally feasible for women who need to pump at work. Using a bottle warmer to scald in about 5 minutes is much better than needing access to a stove and 15 minutes of your time.

Method #3 (Best): Sous Vide Your Milk

I don’t know if anyone else out there has done this before – I mean, I’m sure someone has. No idea is really new. But this idea came to me without any prompting, and I felt like a genius.

Sous vide is a method of cooking where you put food (typically meat or fish) in a Ziploc-style bag and immerse it in warm water. 

For example, if you want your steak to be exactly 135 degrees, you set your water temperature to 135 degrees. The sous vide device circulates the water while heating it to your specified temperature, and with some patience, your immersed food will eventually reach the same temperature of the water. You can’t overcook food when you cook it sous vide.

Why Scald Milk Sous Vide-Style?

There are SO many pros to scalding your milk with a sous vide device:

  1. Heat your breast milk to your specified temperature without having to sit, wait, or test the temperature.
  2. You can scald your pump parts simultaneously.
  3. You can scald at a lower temperature.
underwater view of sous vide breastmilk and pumping parts

According to the book that everyone references for high lipase information, Breastfeeding: A Guide for the Medical Profession by Lawrence & Lawrence, these are the options for scalding your milk and destroying lipase:

  • 180° F – instant
  • 163° F for 15 seconds
  • 144.5° F for one minute

Most people rely on the 180° F option because it’s foolproof. But when you’re heating under very controlled conditions, you can choose a lower temperature, which is far superior.

And heating milk gently at a lower temperature is actually how milk banks do it. According to Mother’s Milk Bank, their donated breast milk is heated at 144.5° F for 30 minutes. They explain this kills unwanted viruses and bacteria “while preserving a high percentage of the beneficial nutrients and immune properties.”

Now, 30 minutes is excessive – one minute holding at that temperature would do it. But it gives me a lot of peace of mind that I can better preserve the good components of my milk while getting rid of the lipase.

How to Scald Milk Sous Vide-Style

To sous vide your milk, you need a sous vide machine. This one from Joule is amazing. I use it every day to scald my milk, but it also makes the BEST chicken breast ever (149° F is perfect for chicken breast!).

You can put your sous vide machine in any container you have – if you have a big pot, that’ll work. My husband gifted this to me for Christmas one year, so he also bought this sous vide container, but you don’t need anything special.

filling sous vide bucket with water

In the Joule app, I set the temperature to 144.5° F.

Setting Joule app temperature

After I start the sous vide machine, I start pumping. I use the wearable Willow pumps – I go back and forth between the Willow Go and the Willow 3.0. You can read my review of these two pumps here

my milk is pumped and ready for scalding

By the time I’m finished pumping, the water is heated. I pour my milk into a breastmilk storage bag. I use and love Lansinoh and Baby Lemon. The Baby Lemon brand bags are really thick and they have some nice features, like a pour spout. But they’re pricier than the tried-and-true Lansinoh bags.

Then, I submerge the bag in the water. Sometimes, I clip the milk bag to the side of my bucket.

baby lemon milk bag in sous vide

It’s important to note that your milk needs to reach 144.5° F and THEN hold for 1 minute. It will take several minutes in the heated water to reach 144.5° F, so I personally wait about 10-15 minutes before taking out my milk and putting it in the freezer. 

You can also test the temperature as you go until you get a feel for the timing.

testing temperature of scalded milk from sous vide

The timing doesn’t have to be perfect with sous vide, though. You could technically let it sit there and hold at your scalding temperature for several hours, though I wouldn’t recommend it.

waiting for milk to be done to sanitize pump parts

Now, I also sanitize my pump parts in this water, but I do the milk first. When the milk is done, I then increase the temperature to 155° F and add my rinsed-off pump parts to sanitize them.

sanitizing pump parts

According to the World Health Organization, bacteria is rapidly killed at temperatures above 149° F, so I just add on a few degrees for good measure.

That’s it!! Completely hands-off and foolproof. 

Sous Vide & Scalding Milk FAQs

OK, I had a LOT of questions when figuring out this sous vide solution, so if you do, too, I hope to answer them all here.

Q: Will the plastic from the breastmilk storage bag leach into my breastmilk?

A: I was really worried about plastic leaching into my breastmilk, so I started off by trying to submerge my stainless steel bottle. But it floats to the top and I couldn’t find a decent way to keep it underwater.

Good news, though: heating milk inside your breastmilk storage bag using the sous vide method is considered safe.

a look at my milk and pump parts sterilizing

High-density polyethylene, low-density polyethylene, and polypropylene are the safest plastics out there. They’re resistant to sub-boiling temperatures, and they aren’t toxic. As in, you could cut them up and eat them and there’d be no toxicity risk. (Information from Cook’s Illustrated, Is Sous Vide Safe?)

Most breastmilk storage bags, like Dr. Brown’s, Kiinde Twist, and Lansinoh, are made of low-density polyethylene and would be safe to use in a sous vide machine.

I decided that I was OK with heating my milk in the breastmilk storage bag, but if this is worrying for you, you can definitely look into heating it inside a stainless steel bottle – you’ll just need to find a good way to keep it submerged in the water.

There are also silicone breastmilk bags available on Amazon, which are reusable, albeit expensive. Finally, most milk banks pasteurize their donated milk in glass bottles, but just be careful – glass can shatter when it changes temperature.

Q: How do I know if my milk has been properly scalded?

A: Your milk will definitely be properly scalded if you leave it in the sous vide water bath for long enough. But if you want to take the milk out as soon as it’s scalded, you can test and time things using a thermometer. I recommend Thermapen, which is insanely accurate, durable, and fast.

Once your water is heated, stick a thermometer in your milk bag (while it’s submerged). Set a timer and pay attention to when your milk hits 144.5° F. Then, count out 60 seconds. At that point, your milk is properly scalded, and the lipase has been destroyed.

For a while, I actually scalded my milk at 147° F, just to make sure it was getting hot enough. I got more comfortable as I went and decided to go with the recommended 144.5° F.

testing the temperature of my milk in the sous vide water bath

Now, you know exactly how long it takes to scald your breastmilk!

I personally just leave my milk in there for 10-15 minutes, and I’ll know it’s good to go without having to pay close attention or set any timers.

Q: Do I have to put my milk bag in an ice bath after I sous vide it?

A: No, you don’t! The whole point of putting your scalded milk in an ice bath is to ensure it doesn’t keep heating up. You don’t want to overheat your breastmilk because it starts killing all the components that make it so beneficial for your baby.

However, when you sous vide the milk, it cannot keep increasing in temperature once it reaches the temperature of the water. 

I personally put my milk in an ice bath the first few times out of habit, but I then realized it wasn’t necessary.

putting milk in an ice bath but really just out of habit

After it’s heated, I just towel off the milk bag and put it straight in the freezer.

drying off wet milk bag

Q: How long do I need to keep my pump parts in the water bath?

This is a great question, and I haven’t found a definitive answer. But here’s what I do know:

  • The CDC recommends boiling pump parts for 5 minutes.
  • According to the World Health Organization, bacteria is rapidly killed at temperatures above 149° F.

So, you know… I just leave my pump parts in a 155° F water bath for 30 minutes or so. I figure that’s over and above and will properly sanitize everything.

overhead view of milk and pump parts scalding and sterilizing

There is no harm in leaving your pump parts in this water for an extended period of time. The only hangup is going to be removing the parts and letting them dry so you can use them again.


I sincerely hope this article helps another mom out there who just realized her breastmilk turns soapy or metallic after sitting in the fridge or freezer. It’s absolutely devastating when you first find out, but there are ways to live with it and store your milk.

The sous vide method has changed my life. I know that sounds dramatic, but it has freed up my time and has kept me motivated to keep pumping. 

If you have ANY tips or tricks, please don’t keep them to yourself. Share them in the comments!!

Also, I’ve never met anyone who also deals with this, so I’d just love to hear from someone else who is going through what I am.

By Rebekah

By Rebekah

I'm a work-from-home mom with a supportive, hard-working husband, two toddlers, and a newborn. In the business world, I'm a copywriter with a deep background in marketing and SEO. At home, I'm always looking for mom hacks, the best projects and toys for my growing kiddos, and ways to solve everyday mom dilemmas. Whatever I find, I'm sharing on this blog, which is my passion project!

Join the Conversation!

5 1 vote
Article Rating
Notify of
Newest Most Voted
Inline Feedbacks
View all comments
Katelyn Meek
Katelyn Meek
6 months ago

Thank you thank you thank you for this. 2 gallon bags full of Lansinoh milk bags all to waste because I didn’t know about high lipase.
No one does!! This is SUCH amazing info. Thank you very much for your time typing it all out!! I have a sous vide machine in my Amazon cart now! I did find these sous vide magnets on Amazon that look pretty cool to possibly hold the bags?
A clip works just as well though for less $
Thank you again<3333

6 months ago

Thank you SO much for sharing this Rebekah. I’ve recently discovered that my entire freezer stash is metallic tasting, and my refrigerated milk is only lasting 3 days. I felt so overwhelmed by the info about scalding over the stove or in the warmer until you shared this, because we have a Joule already and the temp control aspect seems so much better. And sanitizing the pump parts at the same time is GENIUS. Trying this tomorrow 🙌🏼 Thank you for helping other mamas!! I appreciate you!!

5 months ago

Thank you so much for posting this! Milk in the fridge only lasted 16 hours before the metallic taste started and I was spending hours every day scalding on the stove. The sous vide has changed my life! Thank you thank you!

4 months ago

Hi, I just discovered yesterday that my milk has been taking on a soapy taste in about 16-24 hours after pumping. Still in the initial stages of heartbreak since I go back to work in two weeks and have worked so hard to build a freezer stash 🙁 BUT your article has given me real hope!! Thank you very much for sharing this method and your experience. One question – after scalding with this method, how long can you general freeze the milk for? Did you have any issues feeding to baby weeks/months later? I recognize this might differ depending on the person. Thank you!

4 months ago

THANK YOU for this incredible write up. I had over 400 oz of milk frozen before realizing my baby would not drink it. I switched over to sous vide scalding a few days ago and am starting to save up frozen milk for an upcoming trip. Having a workable solution has helped me get over losing my existing freezer stash and focus on the help it’ll bring (I’ll be donating the 400 oz to a local milk bank that gives to NICU babies). Again, thank you!

4 months ago

I was trying to think of better ways to do this than with a bottle warmer and the sous vide is genius!

3 months ago

I just have to say thank you!
I just found out all the milk in my freezer (almost 400oz) is high lipase and baby won’t drink if it’s been over a couple weeks in the freezer (the taste/smell is stronger) as an exclusive pumper I felt completely devastated as I was hoping to be able to stop a few months shy of baby girls 1st birthday and use my stash!

I scalded my first batch the other day and was so defeated by the process, upon doing more research I came across your blog post and I’m so excited to try the sous vide method! I just purchased all the necessary things from Amazon and can’t wait to try it out!

11 days ago

This is a genius idea! I’m going to do this as I build my stash for my baby before I go back to work. I had to donate extra milk with my older kids because of the same issue.

Suggested articles for you:

Get notified of new articles

Pin It on Pinterest

Share This