Soap Dough Experiments: Potassium Stearate

Soapmaking Forum

Help Support Soapmaking Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Johnez

What if I....
Supporting Member
Joined
Mar 29, 2021
Messages
574
Reaction score
1,123
Location
Omaha, NE
First up in the soap dough single fat experiments is a hard one, the infamous Stearic Acid. For anyone following along, @ResolvableOwl has pointed out my SA is not pure stearic acid, but actually a combo of stearic, palmitic, and small amount of myristic acid. This is apparently common, though not widely known so double check your sources if you're using SA.

250 g SA

57.36 g 90% KOH (33% lye concentration)

116.46 g water

37.5 g glycerine (15% of SA weight)

Procedure:

Heat SA on high in crock till fully melted, mix lye into water, combine lye into fat. Add glycerine. Using hot process as apparently this is the only route when using stearic acid.



Results:

Instantly solidified where lye was poured. No point in stick blending, used stiff spatula to fully incorporate SA and lye. In hindsight it might have been a better idea to add the glycerin into the melted SA and then add the lye water. Perhaps having the stick blender ready might have better been able to fully blend. 5 minutes in the consistency was that of regular old coconut oil. 20 minutes in, soap has expanded and feels slightly "airy," or foamy, the expansion phase-roughly twice the volume but no danger of volcano. Knocked down and folded back in. 10 minutes later repeat. 10 minute later repeat. I've never had this happen with other SA heavy recipe so this is kind of new. No separation, however, not a consistency I'm comfortable with.

A break to describe a few errors:

I had mixed my lye first and then took forever to heat up my SA. The lye had likely significantly cooled, which DeeAnna advises against. Oops. In addition I probably should have set my crock on low after mixing everything. I'll try to correct the process next time.

Back to procedure:

After over an hour worth of beating the heck out of potassium stearate I decided to call it. Scooped 72.8 g into a small plastic pot and 331 grams into a gallon Ziploc which was later vacuum sealed using the immersion method. At this point the mixture was creamy, about the consistency of hair gel maybe thinner. In the bag I noticed some hard lumps. Argh.

Zap test: zero zap across multiple points. Tested at first stirring and at the end.

Tomorrow: initial results on consistency, comparison between pot and bag storage.

Feel free to point out errors in process, ratios, or suggestions. I would greatly appreciate it. This isn't a total disaster and hopefully can be something interesting to build off of. I've learned a fair bit here, and have come to some conclusions I might not have if I had simply weighed pros and cons. I'm sure some may see this as a convoluted or unnecessary thing to do, but I think sometimes experience is louder and more convincing lol. Regardless I think I can safely say I've picked a fat that nobody else has thought to go 100% in on. :+)
 
Last edited:
Great experiment, good write-up!
Since the reaction between lye and FFAs is done within seconds, there is actually no need to stir it longer than, say, one minute, until everything is incorporated. But it's okay as well when you stick to a proper HP protocol, just for the sake of comparison.

And also thanks for the attribution of the ambiguity of the commercial name “stearic acid”. If someone doesn't know (i. e. their “stearic acid” in fact contains a considerable fraction of palmitic acid), the effect would be a slighly elevated “superfat”, i. e. it'd fail the clarity test, but it's not in danger of being lye-heavy.

I second you that the order of additions was a bit unfortunate. I'd have heated the KOH + water + glycerol first, and then sprinkle in the stearic acid, tsp by tsp under heavy stirring.

You now have a ziplock bag full of potassium stearate goo? Could you knead out the lumps? How does it feel, back at room temperature? How does it LOOK? The amount of glycerol is probably not enough to make it transparent.
I admire you for your patience at this low water content. My experiences were that it is effectively unworkable with when there isn't a whole lot more water in there than stearate.


ETA: Please take my comments with a grain of salt (literally, lol), since I have gained my experience by playing around with sodium stearate. Potassium makes soaps that are much more resistant to crystallisation, which might help you out to quite a degree, idk. My main experience with potassium soaps of hard fats is single-digit percentages for opaque liquid soaps.
 
Checked up on my potassium stearate this morning. The small portion in the pot is chalky and crumbly along the top, with a bit of give when I stick my finger in there, as if a dry crust formed on top of a still soft core. Ziploc bag has the consistency of very thick clay. Not Play-Doh consistency, quite a bit thicker.

@ResolvableOwl I kneeded as many of the lumps as I could. Regarding water content, I honestly wasn't sure how this would play out since KOH is in the mix and I added a heavy amount of glycerin. Also, it is not transparent. I had a reasonable guess from the CO/SA soap made in the past, and to be honest would have been ok with that result. Mixing in more water probably would have yielded a better results. I'll pull the "dough" out of the bag and play with it a bit. I'm afraid hitting the air will harden it up with the way it behaved in the pot.
 
Last edited:
An addendum to the update:
Pulled out the potassium stearate from it's Ziploc bag for some observations. Firstly, it's pliable but incredibly thick and difficult to work with. The pliability is somewhat like very heavy thick clay with a waxy texture. Not super sticky, but my hands got coated in a thin layer of the stuff anyway. It stretches, will break, and "folding in" does not fully incorporate two separate planes, though I think possibly with time they may fully "fuse" together.

Now I feel there's some potential here, the next experiment will involve melting down a piece. I'm not sure how that will work, if there are any aids to the process (additional water like in regular rebatching?).

One interesting thing to note, when I placed the potassium stearate back in the Ziploc bag and did the immersion technique to vacuum seal it I had quite a layer of it on my hands. Washing my hands yielded an incredibly slippery and slick result. I'm tempted to make an extreme shaving soap with a very high percentage of SA to see how it pans out. In fact I'm tempted to lather up a chunk of 100% potassium stearate, such an easy experiment ha!
 
Feel free to point out errors in process, ratios, or suggestions. I would greatly appreciate it. This isn't a total disaster and hopefully can be something interesting to build off of. I've learned a fair bit here, and have come to some conclusions I might not have if I had simply weighed pros and cons. I'm sure some may see this as a convoluted or unnecessary thing to do, but I think sometimes experience is louder and more convincing lol. Regardless I think I can safely say I've picked a fat that nobody else has thought to go 100% in on. :+)
This is how new ideas comes about, and building on something that already exist, and turn small variations into new ideas and techniques may evoke inspiration and ideas in yourself and others.

I have come up with new ideas regarding things that I haven`t seen or heard from other places, simply because I have done exactly what you have done here, experiment even though it sounded crazy.

Ordinary, soft soap ends, they are really pliable, can they be used like Fimo clay? Hey, it works! Experimenting. Shaving soap as soap dough? Nope, that can`t be done. Wait, can it? Hey, yes it can! Experimenting. Sticky doug problem solving? Experimenting, using a technique I already used in baking.

I have a huge list of other things, but the point is simply - apply one thechnique or idea used in one area, and translate that knowledge into other areas, take into account the variables and play with the outcome. And Bobs your uncle (unless he is Jeremy, then Bob is out of the picture)

Feedback: I have not seen pictures so I don`t know how the soap looks like, so don`t take my take my comment as gospel.
Had it been me I may have added the glyserine along with a small spoon of aditional water at the end, and I may have not waited for a full hour, at least if it was almost zap free before the hour was up. But then again, this was your experiment and you did what you thought was best at the time.

When I use the HP method (for shaving soaps or regular soaps that I make using essential oils as fragrance) I finish up the soap if I see it has the perfect consistency to pour, even if it should be a tiny bit zappy (depending on the zap of course!)
The soap will finish the saponification in the mold after all, and I`ll rather have fluid soap that is almost zap free, than zap free soap that is more lumpy.

PS! Thank you to @ResolvableOwl and you for reiterating the fact that Stearic Acid is not just a static thing, but come in various degrees of palmitic acid, depending on the source. (doh...) I did not know this, thank you both!

In fact I'm tempted to lather up a chunk of 100% potassium stearate, such an easy experiment ha!

If it is zapless, why are you still talking, dooooo it:nodding:
 
Firstly, it's pliable but incredibly thick and difficult to work with. The pliability is somewhat like very heavy thick clay with a waxy texture. Not super sticky, but my hands got coated in a thin layer of the stuff anyway. It stretches, will break, and "folding in" does not fully incorporate two separate planes, though I think possibly with time they may fully "fuse" together.
If it were me and regular soap dough, I'd say it had dried out a bit too much. When I've had dough like that (I'm quite familiar with the consistency you describe!) I find that a _lot_ of kneading, maybe an hour or so, can help, but a slightly easier fix is to knead in a separate batch which is overly damp.
I'd be inclined to chop it as finely as I could and put back in the back with a small amount of water. Leaving overnight would probably help it be absorbed, then you could try kneading it through and see if you get a better consistency.
All of this assuming you would like to achieve a more standard soap dough consistency, of course...
 
If it is zapless, why are you still talking, dooooo it:nodding:

Time flies when having fun, will tomorrow and report back. I actually gave it a try but used too much water and didn't have the time to correct it. D'oh!
If it were me and regular soap dough, I'd say it had dried out a bit too much. When I've had dough like that (I'm quite familiar with the consistency you describe!) I find that a _lot_ of kneading, maybe an hour or so, can help, but a slightly easier fix is to knead in a separate batch which is overly damp.
I'd be inclined to chop it as finely as I could and put back in the back with a small amount of water. Leaving overnight would probably help it be absorbed, then you could try kneading it through and see if you get a better consistency.
All of this assuming you would like to achieve a more standard soap dough consistency, of course...

Hmm, perhaps I kept it in the pot too long. It was probably ready way sooner than when I eventually pulled it out of the pot.

I will try your easy method (chop and add water) suggestion on a portion tonight as I most definitely would like a regular dough consistency. I got big strong hands, however years of manual labor has taken its toll on the connective tissue. Thanks for the suggestion. :)
 
slightly easier fix is to knead in a separate batch which is overly damp.
I'd be inclined to chop it as finely as I could and put back in the back with a small amount of water.
Or knead in more glycerol. It helps stop the water loss through evaporation (hygroscopic), makes the soap become more water soluble, and co-jellifies (don't know if there is a word for it – maybe plasticiser?) the stearate.
 
Or knead in more glycerol. It helps stop the water loss through evaporation (hygroscopic), makes the soap become more water soluble, and co-jellifies (don't know if there is a word for it – maybe plasticiser?) the stearate.

I used 15% (of weight of stearic acid), I'm curious if there's some sort of guideline on adding glycerol. I've used 10% in the past but read 15% is used for stearic acid because of the fact that it was stripped. Not sure if there are actual rules or ways to figure this out.
 
I can't give you numbers, but I know that when you add “enough” glycerol, the melt will stay transparent, yet solidify to something similar to M&P base. Incidentally, most M&P soap ingredient lists will start with sodium stearate, water, and glycerol (not necessarily in this order, but you get the point).
 
I can't give you numbers, but I know that when you add “enough” glycerol, the melt will stay transparent, yet solidify to something similar to M&P base. Incidentally, most M&P soap ingredient lists will start with sodium stearate, water, and glycerol (not necessarily in this order, but you get the point).
So I assumed they must use a TON of glycerol if they're using NaOH-yep! So I did a bit of research again, as I was thrown off by the noticeable inclusions of non-soap ingredients the last time I gave M&P a look. This person seems to have knocked it out of the park:

https://thenerdyfarmwife.com/diy-melt-pour-soap-base/
 
That's a good find! I'm always on the search how to improve my own recipe(s). I personally had not so much luck with glycerol-only M&P and have learned to appreciate propylene glycol (sharper melting point, less viscous melt, and IME also a bit less sweating).

But the gist of this, like just about any M&P recipe, is 1:1 oils-polyol ratio.
 
That's a good find! I'm always on the search how to improve my own recipe(s). I personally had not so much luck with glycerol-only M&P and have learned to appreciate propylene glycol (sharper melting point, less viscous melt, and IME also a bit less sweating).

But the gist of this, like just about any M&P recipe, is 1:1 oils-polyol ratio.

She mentions using arrowroot in her recipes for it's soaping benefits, and incidentally it happens to sweat less. I found the soaping benefit interesting and will stick it on my "additives to try list" when I get my basic shave soap formula down.

As for my own little batch, I opened it up and added 37.5 g glycerol (doubling it to 30% of fat weight) and 50 g of water to help loosen it up a bit. I also combined the little pot I had set aside into the baggie, which would have been useless to use anyway due to the crumbly crust that formed almost immediately.

It is now the consistency of very thick glue, which isn't ideal for working with right now but I can wait it out and open it to air to firm up later (I think!), but it did allow me to knead through some of the smaller pebble sized lumps and it is mostly uniform texture now. We'll see what tomorrow holds.
 
Update and picture time!

@Bubble Agent : I have finally succeeded in shaving with this concoction. It was interesting, which is a short way of saying I don't really know what to make of this heheh. Firstly, it lathered, but took some effort. I had actually tried this the day you encouraged it, however the brush was too wet and I really was in a rush to get to work, so I took extra care in this today. I think it was still too much water. Unfortunately this soap seams to really need the water (along with other fats) as it had a difficult time making anything substantial. I only did two passes, was not confident going against the grain with this stuff. Very little cushion and thin on the face.

@ResolvableOwl , @Tara_H I followed both bits of advice and added glycerol (doubling to 30%) and water (added 50 grams). The dough resulting after 2 days rest was VERY pliable, however also very sticky. I don't think cornstarch or arrowroot would have helped in this case, I probably should have gone a little lighter. Separate pieces incorporate seamlessly, which is great. Handling this stuff is a bear however. I used gloves as I didn't want to contaminate the dough. The consistency is close to play doh, a tad looser.

Honestly the stickiness isn't that big a deal as I'm not really attempting to form any complex shapes or anything, it's all going in the pot anyway. The only issue I can see is the losses from the soap sticking to the gloves/baggie. I'm tempted to make this (and all other single fat doughs) with a small portion (10%) of Castor Oil as I plan to include it in all recipes anyway.

Fun stuff. :)
 

Attachments

  • IMG_20210916_134656421.jpg
    IMG_20210916_134656421.jpg
    93.5 KB · Views: 5
  • IMG_20210916_133139440.jpg
    IMG_20210916_133139440.jpg
    262 KB · Views: 5
  • IMG_20210916_132319345.jpg
    IMG_20210916_132319345.jpg
    303.3 KB · Views: 5
  • IMG_20210916_131621046.jpg
    IMG_20210916_131621046.jpg
    320.6 KB · Views: 6
  • IMG_20210916_131200543.jpg
    IMG_20210916_131200543.jpg
    229 KB · Views: 6
  • IMG_20210916_131108453.jpg
    IMG_20210916_131108453.jpg
    239.4 KB · Views: 6
Yay, congrats! This was just the first step, so keep at it! And yes to the castor!

I have to pop off right now, but will read your post a bit more when I don`t have anyone asking for dinner every 5 minutes, lol.
But well done so far! I`ll be back! 👍
 
Update and picture time!

@Bubble Agent : I have finally succeeded in shaving with this concoction. It was interesting, which is a short way of saying I don't really know what to make of this heheh. Firstly, it lathered, but took some effort. I had actually tried this the day you encouraged it, however the brush was too wet and I really was in a rush to get to work, so I took extra care in this today. I think it was still too much water. Unfortunately this soap seams to really need the water (along with other fats) as it had a difficult time making anything substantial. I only did two passes, was not confident going against the grain with this stuff. Very little cushion and thin on the face.

Separate pieces incorporate seamlessly, which is great. Handling this stuff is a bear however. I used gloves as I didn't want to contaminate the dough. The consistency is close to play doh, a tad looser.

Honestly the stickiness isn't that big a deal as I'm not really attempting to form any complex shapes or anything,
it's all going in the pot anyway. The only issue I can see is the losses from the soap sticking to the gloves/baggie. I'm tempted to make this (and all other single fat doughs) with a small portion (10%) of Castor Oil as I plan to include it in all recipes anyway.

Fun stuff. :)

Hi again!

Nice pictures, it was easy to see that you made real suds there! How long did it manage to stay that way without deflating, did you notice?
I agree, if it was thin and not cushioning it needs help from other fats/oils. If you add 10% castor it will help with the easier build up of the lather.

I am looking forward to hear what you think when you try out other oils and combinations. You said you didn`t know what to think about this one, but if you venture out later on, I think you will find over time that the best soap is the one with different oils together. And then you will guaranteed notice a difference between the one you made here, and the other ones. I haven`t usually added castor to the earlier shaving soaps, and the last one I made I tried it for the first time. It will be a staple from here on out for me at least. I think it added something special compared to my other recipes.

I have found that making shaving soap is like making a cake (I cook and bake a lot, lol).
Add just eggs (single oil) and you get a boiled/fried egg and nothing more. Add flour and whip yolks and whites separate and you can make a sufflee. Add Sugar, butter and chocolate and you get a chocolate cake. Different ingredienst will bring different things to the table, and together they make up great stuff.
But I do remember you are just doing this to experiment, so totally get that exploring different things first. Which is the fun part of this type of thing.

PS! You can use a spatula to scrape off the leftover soap and lather up with that. Or just rub the gloves on wet face. Preferably you own...heh (ok, not very practical though... I would opt for the spatula thing😁 )
 
Hi again!

Nice pictures, it was easy to see that you made real suds there! How long did it manage to stay that way without deflating, did you notice?
I agree, if it was thin and not cushioning it needs help from other fats/oils. If you add 10% castor it will help with the easier build up of the lather.

I am looking forward to hear what you think when you try out other oils and combinations. You said you didn`t know what to think about this one, but if you venture out later on, I think you will find over time that the best soap is the one with different oils together. And then you will guaranteed notice a difference between the one you made here, and the other ones. I haven`t usually added castor to the earlier shaving soaps, and the last one I made I tried it for the first time. It will be a staple from here on out for me at least. I think it added something special compared to my other recipes.

I have found that making shaving soap is like making a cake (I cook and bake a lot, lol).
Add just eggs (single oil) and you get a boiled/fried egg and nothing more. Add flour and whip yolks and whites separate and you can make a sufflee. Add Sugar, butter and chocolate and you get a chocolate cake. Different ingredienst will bring different things to the table, and together they make up great stuff.
But I do remember you are just doing this to experiment, so totally get that exploring different things first. Which is the fun part of this type of thing.

PS! You can use a spatula to scrape off the leftover soap and lather up with that. Or just rub the gloves on wet face. Preferably you own...heh (ok, not very practical though... I would opt for the spatula thing😁 )

Hey Bubble Agent, thanks for stopping by. :)

Unfortunately the SA soap disappeared quite quickly, I had to hurry up as it did seem to evaporate almost faster than I could shave. I got to push the limit, and wasn't expecting anything life changing though that would have been neat.

Regarding making shave soap, there is so much room to run in regards to experimenting. Specifically in vegan/palm free which has not been thoroughly delved into yet IMO. In my MdC clone thread I've dabbled about and may have annoyed some but I believe I'm tantalizingly close to a "good" formula.
 
Hey Bubble Agent, thanks for stopping by. :)

Unfortunately the SA soap disappeared quite quickly, I had to hurry up as it did seem to evaporate almost faster than I could shave. I got to push the limit, and wasn't expecting anything life changing though that would have been neat.

Regarding making shave soap, there is so much room to run in regards to experimenting. Specifically in vegan/palm free which has not been thoroughly delved into yet IMO. In my MdC clone thread I've dabbled about and may have annoyed some but I believe I'm tantalizingly close to a "good" formula.

Hey, that is great! Not the disappearing act of the foam of course, but that you have tried things and getting closer to what you want in a shaving soap! Which is the purpose of what you are doing.

I must have missed that thread, I`ll pop off and check it out after this :)
 

Latest posts

Back
Top