Butter Soap Curiosity

I had some unsalted butter that needed to be used up. However, I became curious about a pure butter soap: has anyone ever made one? How will it perform as a soap? Will it make a great soap like Castile or will it suck like a 100% castor soap?

I tried looking up information on the forum as well as on the web & I came to the conclusion that this is the perfect time to make an experiment on it. As of now, it's in the fridge in an attempt to avoid gel. My only wish is that I actually left it as 100% butter, but I added a bit of corn oil to it (may have been counter-productive on my part). Still, I hope that this experiment will answer my questions.

A forum buddy got me interested in trying butter a year or so ago. I tried several different butters including ghee and all had a sour off smell when I washed my hands with the soap

cmzaha said:

A forum buddy got me interested in trying butter a year or so ago. I tried several different butters including ghee and all had a sour off smell when I washed my hands with the soap

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I experienced that myself when I used the residuals on my hands. I can definitely say that a butter soap, made mostly of butter, will leave a smell on your hands. It also hardens and saponified quickly. I left it overnight in the fridge and was surprised to see it was hard with no zap when the morning came.

I am thinking that I could do three things with the soap bars:

1. Let a bar cure at room temp
2. Let a bar cure in the refrigerator
3. Use a bar once a week to wash my hands (just to experience the process)

I think I might even cut one of the soap bars in half to see how it will cure in the freezer. I think I will note the effects of each environment as well.

I left some curing for over 6 months before tossing the batch.

Wow. Was the scent that unbearable or did the soap change for the worse?

It's officially 4 weeks from the time I made this soap. The soap bars have hardened quite a deal and no DOS is detectable.

For the sake of information, I have left a bar in three locations: the freezer, the refrigerator, and in a room-temperature curing spot. The three soap bars all have a different smell. The bar in the freezer smells like frozen butter while the bar in the refrigerator smells like movie-theater butter sauce. The room-temperature bar smells the worst of the three. It does not smell like ammonia, puke, or anything rancid, but it does not smell pleasant either.

I cut a piece of each to wash my hands with. At a 4 week cure, the lather nicely. It does leave a slippery feel upon rinsing that I do not like as well as a buttery scent. Fortunately, the scent does not linger and it leaves the skin feeling soft.

LunaSkye said:

Wow. Was the scent that unbearable or did the soap change for the worse?

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The soap really did not change, but I could smell the residual odor on my hands and did not like the smell

I made a soap with butter at 10% a while back and let's just say that it's not the best bar of soap I have made and I would probably not make it again.

There's this smell that lingers on the skin for me and I don't like it. The bar on its own [I left it to cure at room temperature] had this really awful vomit-like smell.
None of my friends that smelt it likes it at all. The texture itself is okay, but I really don't think I would make it again.

Texture of Soap: It was pretty soft when I got it out of the mold, the recipe should be something like 20% coconut, 20% palm, 10% butter, probably 30% olive and 10% avocado or sweet almond. I don't have the recipe with me but it should be somewhat like that. When I washed my hands with it, it was pretty okay but not the best. I don't really notice a big difference with it.

Smell: It smells. My friends, all 14 of them, agreed that it smelt like vomit. [Let's just say that everyone didn't want to smell any of the other soaps I've made] And I found that the smell of the soap lingers on my hands after washing. It's especially so after maybe 2 or 3 weeks of cure but after 4 weeks, the smell of the soap doesn't lingers on my skin. Thank goodness.

Colour: It colours the soap a very pretty yellow.

All in all, no more butter soap for me. But it might be great to you know, make a small batch of it and see how it works or smell. It might be because of my climate or where I've stored it that may have affected how it smelt a little???

Just FYI, Eden Botanicals produces a CO2 extracted butter EO - the reviews say is smells like butter popcorn. I haven't tried it, but they also have a few specialty (unusual) EOs (black currant, hay, etc.) that I'd like to try. They're on the expensive side, so they might price out of the range for soap, but they could be used in other products. (EDIT: It's actually considered a milk fat extract, not an EO.)

Hey LunaSkye, instead of butter have you tried GHEE, which is clarified and purified? If I remember right GHEE is in the column in soapcalc too.

I have tried different brands of ghee, most brands of butter available in So Cal and they all produced a soap that had a lingering yuck smell.

summerflyy said:

All in all, no more butter soap for me. But it might be great to you know, make a small batch of it and see how it works or smell. It might be because of my climate or where I've stored it that may have affected how it smelt a little???

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10% butter is be a lot better than what I made. It stinks when wet and the smell lingers. I used a bit of each bar at a 4-week cure. It did leave my hands feeling soft, but I started to wonder if it had a bleaching quality to it as my hands look a little lighter to me than normal.

sassanellat said:

Just FYI, Eden Botanicals produces a CO2 extracted butter EO - the reviews say is smells like butter popcorn. I haven't tried it, but they also have a few specialty (unusual) EOs (black currant, hay, etc.) that I'd like to try. They're on the expensive side, so they might price out of the range for soap, but they could be used in other products. (EDIT: It's actually considered a milk fat extract, not an EO.)

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I seen the extract. I rather not have anything that smells like movie theater popcorn. I haven't been to the movies in ages and I miss that unhealthful treat. It's also kinda tricky using a pot to make popcorn.

goji_fries said:

Hey LunaSkye, instead of butter have you tried GHEE, which is clarified and purified? If I remember right GHEE is in the column in soapcalc too.

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I really didn't think about using ghee for my experiment only because I already had the butter on hand and it needed to be used. I imagine ghee being a bit easier to use since it's 100% fat.

LunaSkye said:

10% butter is be a lot better than what I made. It stinks when wet and the smell lingers. I used a bit of each bar at a 4-week cure. It did leave my hands feeling soft, but I started to wonder if it had a bleaching quality to it as my hands look a little lighter to me than normal.

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I feel the same way too about how I think my skin looks a bit fairer ? But it's still not a good enough incentive for me to put any butter into my soaps anymore. 10% and it's more than enough to kill me with the smell !

After 8 weeks of curing, the butter soaps are out for the observing. The top soap is my freezer bar, the square bar is my room-temperature bar, and the vertical bar was cured in my refrigerator.



My room-temperature bar seems to be fully cured whereas my refrigerated bar feels like it needs a bit more time to cure. The freezer bar was the heaviest of the bars and was sweating while it warmed up to room-temperature. I'm thinking that the freezer may have prevented the bar from properly curing but I'm nowhere near surprised since that coldness will freeze water.

My freezer bar and refrigerated bar took on the scents of their environment (not surprised). They all lather up really easily (a little goes a long way). My only regret is not being able to test the soap for each week of curing.

How is the smell?

Obsidian said:

How is the smell?

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My room-temperature bar has a hint of the same stinky smell from 4 weeks ago. The refrigerated bar started to smelled like the compartment that I store my EOs when I first took it out, but it now reminds me of movie-theater butter topping. The freezer bar smelled like the frozen food that had garlic added to it and still has that quality to it today.

Hey LunaSkye,
Thanks for carrying out this experiment and sharing your results!

Just yesterday I was just asking myself the same question considering that butter has a very interesting fatty acid profile unlike the more common soapmaking oils that I know of:
- Palmitic: 31%
- Myristic: 12%
- Stearic: 11%
- Oleic: 24%
- Linoleic: 3%

And I was wondering if this would be the next super soapmaking ingredient!!

I wonder what contributed to the bad smell - maybe the milk products in there?

There are more fatty acids in butter than what most soapers realize if all they're going by is what's in the soap calculators.

Butterfat (milkfat or ghee) is unique in that it contains butyric acid. This is the fatty acid that gives butter (and butter soap) its characteristic odor. '

Ditto for fats such as coconut, babassu, and palm -- they also have fatty acids that the soap calcs don't consider. The caproic, caprylic, and capric acids in these fats (and butter) contribute to their high water solubility and also to their reputation for harsher cleansing. These short-chain fatty acids have more ability to strip lipids (fat) and proteins off the skin, leaving it dry and "tight".

DeeAnna said:

There are more fatty acids in butter than what most soapers realize if all they're going by is what's in the soap calculators.

Butterfat (milkfat or ghee) is unique in that it contains butyric acid. This is the fatty acid that gives butter (and butter soap) its characteristic odor. '

Ditto for fats such as coconut, babassu, and palm -- they also have fatty acids that the soap calcs don't consider. The caproic, caprylic, and capric acids in these fats (and butter) contribute to their high water solubility and also to their reputation for harsher cleansing. These short-chain fatty acids have more ability to strip lipids (fat) and proteins off the skin, leaving it dry and "tight".

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And if I did my math properly, I would have realized that the numbers I posted didn't add up to 100!

In fact on the wikipedia page for Butterfat, it describes an 11% proportion of "Lower (at most 12 carbon atoms) saturated fatty acids"


... plus a whole bunch of other FAs that I was too lazy to transcribe...

Yep. And even if you added up all the percentages of all the fatty acids, you still might not end up with 100% anyways. A fat might not be 100% triglycerides (the fat that contains fatty acid) -- there can be non triglycerides too. Sometimes they are listed as "unsaponifiables" and sometimes they are ignored.