Breast milk is one of the healthiest substances in existence. It’s perfectly formulated to nourish a developing brain and help an infant double in size within just a few months.
The benefits of breastmilk go well beyond nutrition, and numerous studies show that it’s an effective treatment for topical skin issues as well. Breastmilk soap has been growing in popularity with parents looking for natural alternatives to treat infant eczema, and adults are trying it too. But does it work?
Many years ago I attended a homemade ice cream festival hosted by a large group of friends. It was a contest of sorts, where everyone brought their own ingredients and the ice cream was flash-frozen on-site using liquid nitrogen.
There were literally hundreds of flavors to try, but the most unique obviously got the most attention. The star of the show? Breast milk ice cream.
One mother had saved up her extra breast milk and pasteurized it at home before bringing it to share. It turned heads at first, but there’s nothing more nourishing than human breast milk, and most people were just eager to try it.
Fast forward more than a decade later, and I’m tandem breastfeeding two babies under two. At this point, I’m spending most of my time as a dairy animal under my two snoogly babies, but my creative side gets to thinking. What can I make with my breastmilk?
I’m a home cheesemaker, and I got pretty excited about making my own breastmilk cheese. The problem is, you need a lot of milk to make cheese, and my little ones weren’t really leaving any to spare.
My breastfeeding days came and went, and I never actually did anything with my breastmilk besides growing to healthy baby humans. I was content with that…until I found a few spare frozen bags of breastmilk in the freezer.
As luck would have it, a few days later Storey Publishing sent me a review copy of the book Milk Soaps, which takes you through the ins and outs of making soap with any type of milk under the sun….including breastmilk!
Why Make Breastmilk Soap?
So just because you can make breastmilk soap, why on earth would you want to? Beyond the pure novelty of washing with your own homegrown milk soap, there are actually a few good reasons to try it.
Breast milk has a long history of use topically. Studies show that it’s just as effective as hydrocortisone cream in treating infant eczema.
Natural compounds in breastmilk can also be helpful in treating acne and rashes (source) and doctors sometimes even suggest using the antibacterial properties of breastmilk to treat localized infections.
Does any of this come through in a finished breastmilk soap, after the milk has been transformed by lye? Honestly, probably not.
If you add breastmilk into the soapmaking pot with the lye it’s going to be chemically cooked, and any enzymes it may have aren’t likely to make it into the finished soap. So why bother?
Because beyond the micronutrients and enzymes, breast milk is actually great for soapmaking. Breastmilk contains more fat than cow’s milk, which will help make a creamier soap.
It also naturally contains more sugars, and the sugars in milk help promote a silky lather in a bar of the finished breastmilk soap. It’s also high in vitamins which promote skin health, and those all make it through the lye transformation from milk to soap.
If by chance any of the enzymes, anti-microbial agents or other breastmilk compounds make it through into the finished soap, then that’s just icing on the cake.
Choosing a Breastmilk Soap Recipe
Generally, when you make a milk soap, the milk is frozen into cubes which helps to slow down the lye reaction and prevents the milk from burning. Lye gets really hot when it contacts liquid, and that will carmelize the milk sugars (effectively cooking out all the micro-benefits of breastmilk). Here are the basic guidelines that the book Milk Soaps provides for making breastmilk soap:
“Believe it or not, people do use human breastmilk to make soap. It is higher in fat than cow’s or goat’s milk. It also contains lots of sugar and vitamins A (retinol), C, D and E. If soapmaking with breast milk, follow the basic instructions for other mammal milks (freeze the milk, add sodium hydroxide to it slowly, and keep the superfat at 10 percent or below.”
They suggest that any of the recipes in the book can be made with any type of milk, and there are some pretty wild recipes including soaps specifically formulated for donkey and camel milk. (As well as just about every plant-based milk under the sun such as hemp, almond, flax, oat, and almond milk.)
So in theory, you can use breastmilk in any milk soap recipe. The one that caught my eye though? A simple buttermilk castile soap recipe, that’s specifically designed for sensitive skin.
The only oil in the recipe is olive oil, and the milk in the recipe is added in at the end as a mix in (after the lye has reacted with the olive oil). If there’s any chance of maintaining the micronutrients and enzymes in breastmilk in the finished soap, this is it.
The breastmilk won’t have to be frozen into cubes, and you won’t have to carefully sprinkle in the lye to carefully manage the reaction. All you’re doing is making a simple castile soap, without any hard-to-find specialty oils.
The original buttermilk castile soap recipe from Milk Soaps suggests using a bit of natural herbal colorant and a few drops of lavender and peppermint essential oil, which I’m going to skip for the simplest homemade breastmilk soap bar possible.
This breastmilk soap recipe starts as a simple castile soap, and breastmilk is added in at the end. Please read up on soapmaking safety before getting started, and DO NOT use lye around children. This recipe is adapted from the book Milk Soaps, but as always, use a soap calculator to double check any soapmaking recipe before beginning.
Breast Milk Soap
This breastmilk soap recipe starts as a simple castile soap, and breastmilk is added in at the end.
Please read up on soapmaking safety before getting started, and DO NOT use lye around children. This recipe is adapted from the book Milk Soaps, but as always, use a soap calculator to double check any soapmaking recipe before beginning.
Looking for More Milk Soap Recipes?
How much sodium lactate would you use for this recipe?
The usage rate for sodium lactate is 1 tsp per pound of oil.
Would this work with sunflower or rice bran oil for a baby with allergies to all other types?
Every oil has a different effect on the lye, and you’d need to put a modified recipe through a soap calculator to check. I don’t know of any soaps made with just sunflower or rice bran oil, and there’s likely a reason for that. Olive oil is the only single oil soap I know. I’d suggest finding a good recipe for a soap that uses the oils you like and then work on modifying it to add milk rather than the other way around.
Could I use more breastmilk instead of using distilled water?
Unfortunately not. The distilled water is for dissolving the lye, and if you put lye right into the breastmilk it’ll carmelize/burn it in the reaction as it heats up. That needs to be distilled water just for that dissolution step.
Can you use breast milk that has been in the freezer for over 6 month?
Where would one get the other ingredients for milk soap making?
Thank you for your 1st reply.
Good question. I’ll go back through and add some links into this post when I have a minute. For now, there are links to all the soapmaking supplies you’ll need here in this post (also a milk soap recipe): https://practicalselfreliance.com/goats-milk-honey-soap-recipe-beginners/
Is this recipe in fl oz or weight oz? Thanks so much!
Can I used expired bm. I have a stash that’s about 8-10months old in my freezer that I haven’t thrown out yet. Can I use it?
Yes, if it’s frozen but just old. Having been in the freezer for a really long time is fine. Actually spoiled because it sat out and curdled/rotted, no.
I save the extra bm my little one doesn’t finish and keep it in the fridge for milk baths, could I use that milk for the soap or does it need to be “fresh” frozen or never drank from?
Leftover is totally fine, so long as it’s not spoiled.
In ur ingredients, it said 35oz of olive oil, I wonder if it’s supposed to be 3.5oz?
35 oz. is the correct measurement for the olive oil.
Can I use extra virgin olive oil?
Yes, you certainly can. This is what I use for all of my soaps.
Hi! Thank you so much for sharing this recipe!! I have an abundance of frozen breastmilk that’s too old to donate. I’m thrilled to make soap and hoping to also make lotion, body butter, cheese, and maybe even ice cream? Although I’m worried about the edibles as I think I might be high lipaser; my frozen milk tastes bitter while the freshly pumped stuff is sweet. Do you have any experience with that? Would you share any recipes you have for breastmilk? Skincare or edibles?
Kristen Bailey Shields
after the soap has cured, how do you store it for use? How long is it shelf stable?
Store it just like any soap, as the lye more or less pasteurizes everything and makes the milk soap shelf-stable. How long it lasts I can’t say, since we used ours pretty quick, but milk soaps, in general, should keep just like soap on the shelf to the best of my knowledge.
Hi there, what is sodium lactate from the recipe and how much goes into the mixture. It doesn’t appear in the ingredients. Thanks
Sodium lactate is a liquid salt that is added to soap recipes to help speed up unmolding time and also creates a harder and longer lasting soap. The usage rate for sodium lactate is 1 tsp per pound of oils.
I make soap and I know that after molding the soap it gets veeeery hot so wouldnt this completely ruin the nutrients in the milk? Indont see how this would work.
Wether it cooks the milk with lye or while its curing in the mold its still cooking the milk and we dont want that..???
Yes, soap does heat up in the mold however it doesn’t get as hot as the lye water. For this reason, it is better to add the breast milk in at the end of the soaping process. We don’t know for sure how much of the micronutrients and enzymes actually survive the process but there are lots of other benefits in the breast milk that still make it an excellent choice for soaping.
Would it not therefore be more beneficial to make breastmilk soap from melt and pour soap base instead in order to avoid cooking the milk at all?
You could certainly do that if you wish. Many people don’t like using melt and pour bases because they tend to have some more questionable ingredients, but there is always the option of making your own.
With melt and pour you can only add at most 1-2 tsp of additives per pound of base, so you would be practically using almost no milk at all. Not worth it. Cold process is the thing for milk soaps.
I also want to ask, is this recipe gentle enough to use on my baby’s skin? I am guessing it is since you spoke about eczema.
I will make this recipe in a few days and will tell you how I like it. I have sooo much frozen breastmilk that has been there for too long and dont want to just throw it out so I will make soap and use it for other things.
What I did find about melt and pour base is that they have too many strange ingredients that I rather not have in my soap so I may just stick to cold process soap.
This is a very gentle recipe so it should be perfectly safe for baby skin. Of course I would avoid using any essential oils and you should check with your medical provider if you have any concerns.
My understanding is that you have to mix the breastmilk with lye to kill off any bacteria and to cure the breastmilk so it doesn’t turn rancid and go bad. If you’re not mixing the lye directly into the breastmilk, will the breastmilk soap go bad after a few months?
I’m not very familiar with cold processing, after you mix all the ingredients properly and pour it into the mold base to cure for 2-5 days where do you store it during the curing process? And after the initial 2-5 days where do you then store it for the next 6-12 weeks?
I just store mine in my laundry room which is where I make my soap. You just store it at room temperature in a relatively dry environment with good air flow so that it can cure properly.
Thank you for your guidance on this, I have so much breast milk and want to make soap that is shelf stable so I will be trying this soon. My baby has some areas of eczema so I’m hoping this would help. If I wanted to add oatmeal to this, when and how should I do so? Any help is appreciated, thank you!
I honestly have no practical advice as to the health benefits, if any. It’s hard to say if the good parts of breast milk make it through the soapmaking process, so it’s really just a guess.
Hi! Thanks for sharing this recipe — I’m excited to try it out! I was wondering… if I was to add some lavender (or other) essential oil to make the soap smell nice, how much would you recommend using? (Or what would be the max amount you’d recommend? I don’t know if after a certain amount, it throws the ratios off and the soap doesn’t get hard, or some other issue… I’m new to this 😅)
If you’re adding in essential oils, you want to look at the safe usage rate for that particular essential oil. It’s not really about the processing of the soap as much as using a safe amount of the essential oil. There is an excellent essential oil calculator here. https://www.eocalc.com/calculate-usage-rate/