Hard puck of 100% KOH shaving soap?

[cpacamper]

Hi all,

This is my first question so go easy

I'm experimenting with making a shaving soap from an old book by Henry Gathmann that calls for 83% beef tallow, 17% coconut oil and a 78.7% NaOH/21.3%KOH saponification combination, half boiled (I took that to mean hot process).

The lather was very slick and moisturizing, but dissipated rather quickly on my face. "More stearic acid" I'm told. I read somewhere that KOH tends to enhance the tallow's native stearic properties, so I'm going to try a 100% KOH formula this weekend.

My question: While many fine commercial shaving soaps are 100% KOH, they tend to be very soft soaps aka croaps. I'd like a much harder bar. What can I do to make a hard 100% KOH tallow/coconut oil soap? Milling and pressing? Less water in the lye solution? Any suggestions for this newb?

Thanks, all!

 

[Dorymae]

I'm no expert but I am not sure you will get a hard puck soap with Koh. Koh produces soft soap which is why it is used in liquid and cream soaps. NaOH makes hard soap so it is not used in liquid or cream soap. The two are not interchangeable.

I think your best bet to getting a puck soap will be to add stearic acid to your recipe (I think you are getting about as much as you can out of the tallow and still keeping a puck) and keep your percentage the same or slightly tweak them to have slightly more koh.

Good luck with your recipe, be sure to come back and let us know how it went!

 

[FGOriold]

KOH is used to make liquid soap and NaOH is used to make hard bar soap. Combinations of them together can be used for liquid soap or cream soap. I do not think you will get a hard bar with just KOH.

 

[newbie]

This is now a very long thread but it is worth the read. The shaving soap recipe is excellent and there is a fair amount of discussion about KOH/NaOH combinations to get a desired firmness in your shave soap. Definitely worth the time spent to go through it.

http://www.soapmakingforum.com/showthread.php?t=34264

 

[DeeAnna]

You can get a firm bar with 100% KOH, a recipe with a high stearic acid content, and a good long cure time. But you will never get a hard bar. It will always have some degree of softness like waxy modeling clay. Milling will not solve this problem -- it's in the chemical nature of the beast.

Half boiled is not hot process. The answer is rather long and complicated, so I'd recommend you go back to Mr Gathmann for more insight -- he should have explained more about soap manufacturing processes of the day somewhere in his 1893 book -- I'd check the first few chapters.

I see you're documenting your journey on Badger and Blade by describing your first foray into rendering tallow. Nice job!

The person on B&B who said "...tallow soaps were made from hydrogenated beef tallow ... the hydrogenation process converts some of the triglycerides to stearic...." is a bit off base in his understanding of the chemical structure of triglycerides. But small matter -- it doesn't change the point of what you are doing.

 

[wetshavingproducts]

You can get a firm bar with 100% KOH, a recipe with a high stearic acid content, and a good long cure time. But you will never get a hard bar. It will always have some degree of softness like waxy modeling clay. Milling will not solve this problem -- it's in the chemical nature of the beast.

I hate to disagree with DeeAnna, but untrue.

40% SA & 60% CO with 1.5:1 lye water ratio, HP cook will produce a rock hard bar. 100% KOH.

I know because it was one of my experiments that didn't turn out the way I wanted. I now have plenty of hand/bath soap. Lathers pretty creamy.

 

[DeeAnna]

I'm always interested in other people's experiences -- thank you for sharing, WSP.

Using a 30% lye solution (approx 1:2 lye:water), 48% stearic, 52% CO, HP cook ... even after months of cure, the soap still can be dented with moderate finger pressure. Even using up to 30% NaOH doesn't result in a truly hard bar for me.

Maybe it's that last 8% coconut oil that did the trick for you. I've gone the other direction with even higher amounts of stearic acid, and that still ends up with a softer bar. Or you cooked out a lot more of the water than I do. Hard to say.

Not sure why the wide difference in results, but there ya go....

 

[Candybee]

Hmmm... I've used 50% stearic with 50% tallow and coconut oil split 50/50 and got a semi soft soft using 90% NaOh and 10% KOH. It does harden after a while but is still soft enough to imprint if I press my thumb in the bar. I'm skeptical about getting a hard or even firm bar using 100% KOH.

Maybe it has to be mostly coconut oil?

 

[wetshavingproducts]

I'm always interested in other people's experiences -- thank you for sharing, WSP.

Using a 30% lye solution (approx 1:2 lye:water), 48% stearic, 52% CO, HP cook ... even after months of cure, the soap still can be dented with moderate finger pressure. Even using up to 30% NaOH doesn't result in a truly hard bar for me.

Maybe it's that last 8% coconut oil that did the trick for you. I've gone the other direction with even higher amounts of stearic acid, and that still ends up with a softer bar. Or you cooked out a lot more of the water than I do. Hard to say.

Not sure why the wide difference in results, but there ya go....

Going the other way with stearic and the same water ratios still had a soft center, but the top is/was super hard. The water may not have cooked off as much. I think the centers are getting harder, can't push it down anymore.

Cooked them for an hour at 180/190 in the oven. Unsure if that's the difference.

 

[cpacamper]

You can get a firm bar with 100% KOH, a recipe with a high stearic acid content, and a good long cure time. But you will never get a hard bar. It will always have some degree of softness like waxy modeling clay. Milling will not solve this problem -- it's in the chemical nature of the beast.

Half boiled is not hot process. The answer is rather long and complicated, so I'd recommend you go back to Mr Gathmann for more insight -- he should have explained more about soap manufacturing processes of the day somewhere in his 1893 book -- I'd check the first few chapters.

I see you're documenting your journey on Badger and Blade by describing your first foray into rendering tallow. Nice job!

The person on B&B who said "...tallow soaps were made from hydrogenated beef tallow ... the hydrogenation process converts some of the triglycerides to stearic...." is a bit off base in his understanding of the chemical structure of triglycerides. But small matter -- it doesn't change the point of what you are doing.

Deeanna,

I'll refer back to the Gathmann book again about half boiling now that I understand soapmaking a teeny bit more, and I was a bit confused myself by the "hydrogenated tallow" comment, but so it goes.

This quoted from an article here on using KOH:"NaOH soaps can be turned soft in process using glycerine and alcohol; KOH soaps can be turned hard in process using salt." The article does not mention how to incorporate the salt, type of salt (good ol' sodium chloride?), or how much. Do you happen to have any information on this?

I'm going to try a very small HP batch based on the Gathmann recipe this weekend and will report back. I'm hoping a preponderance of KOH will yield longer lasting lather, and if it works I could live with a croap I suppose. Fun experiment for sure!

 

[wetshavingproducts]

Could try discounting the water a lot if you want a hard bar. However, from my experience it's not even glopping it into the mold so much as trying to scoop it up and form it into something that resembles a rectangle. The 60% CO soap was a mistake in the recipe, so I turned it into hand/shower soap. But it is ugly, didn't level, and is rock hard.

 

[DeeAnna]

"...KOH soaps can be turned hard in process using salt...."

Yes, soap made with KOH can be treated with a brine (salt and water) and thus converted to a partly sodium soap. The resulting mixed-potassium-and-sodium soap will be harder ... but it's no longer just potassium soap.

If that's the direction you want to go, I recommend just making a soap with part KOH and part NaOH. Fugeddabout the brine thing.

The brine treatment is more suited to a "boiled" KOH soap that has been saponified and boiled in a bath of excess of lye and water (a la Gathmann), so you're already dealing with a watery soap. The CP or HP soap as we make soap would first have to be dissolved in water, heated, then brine or salt added to the water, cooked gently for a time to allow some of the K (potassium) to be replaced with Na (sodium), add more salt until the brine becomes immiscible with the soap, and finally recover the soap. Quite the process.

 

[DeeAnna]

And bear in mind that a boiled soap does not have the glycerin or superfat in it that a modern-type CP or HP soap has. The boiling and salting-out processes remove the glycerin from the soap. The soap was made with a slight excess of lye, so the superfat was minimal at best.

There is absolutely nothing wrong with using the old recipes -- I certainly consult the old books when researching different types of soaps. That said, I don't believe the results we get are precisely the same as what the "old boys" got. Same ingredients but different methods = different products.

 

[cpacamper]

The experiment failed. The soap was very soft and sticky at first, then firmed up a bit over the weekend into a malleable mass. I mashed the mass into a mug, and using hot water I proceeded to build a fairly creamy, bubbly lather face lathering with my boar brush. Unfortunately, the creaminess disappeared completely from my face after only 60 seconds (kinda like modern Williams with hard water), making shaving a challenge to say the least.

My thought is a 88% tallow/12% CO combo could make a pretty good, hard bath bar as the lather seemed pretty conditioning, but it is not a shaving good soap.