Opinions/Advice on making shave soaps (NaOH only)+ SF%

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First things first.. I am not sure if I am posting this in the correct way lol.. Nevertheless, I am just curious.. I’ve made a few shave soaps and have liked them all, while I’m always open to improving formulations etc.. curious.. what % do other soapers usually super fat their shave soaps? Do you ever switch it up the SF %? If so, is there a particular reason why?
Does anyone have a favorite shave recipe? Is there any specific FA’s or numbers to achieve? Any info to help me formulate a better shave soap os helpful and appreciated..
Also, on a random note, where I live hard water is a very serious issue.. I’ve been using CA to combat that until tonight, I’m literally about to try using Sodium Citrate. Is it true that the higher the SF %, even with a chelator, the more soap scum. I believe so but not certain.
 

Zany_in_CO

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Shave soaps have been discussed many times. It's one of our most popular subjects! Use the Search feature found in the upper right hand corner of this page to discover tons of info that will answer most of your questions. Take a cuppa along and settle in for a bit. Lots of good stuff there! Although, as with all things soapy, you'll get a variety of responses to consider. 🤔
 
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First things first.. I am not sure if I am posting this in the correct way lol.. Nevertheless, I am just curious.. I’ve made a few shave soaps and have liked them all, while I’m always open to improving formulations etc.. curious.. what % do other soapers usually super fat their shave soaps? Do you ever switch it up the SF %? If so, is there a particular reason why?
Does anyone have a favorite shave recipe? Is there any specific FA’s or numbers to achieve? Any info to help me formulate a better shave soap os helpful and appreciated..
Also, on a random note, where I live hard water is a very serious issue.. I’ve been using CA to combat that until tonight, I’m literally about to try using Sodium Citrate. Is it true that the higher the SF %, even with a chelator, the more soap scum. I believe so but not certain.
Your title says that you use NaOH only; can you share your thinking about that? Most of the shave soaps threads here on SMF are discussing shave soap made with KOH + NaOH. Before changing anything else, I would encourage you to try that. This results in a softer soap that can be whipped into a true shaving-cream lather that simply can't be achieved with NaOH alone.

If you go the dual-lye route, you will want to have at least 50% stearic acid content in your shave soap, whether from stearic acid as a separate ingredient, or from tallow and other high stearic fats. However, I don't know if that % will function as well in an all-NaOH soap.

I've been using 8% SF in my dual-lye shave soap and am happy with it. You do get more potential for soap scum with higher SF. In my bar soaps and shave soaps, I have switched from CA to SC, and am very happy with it. But if you have very hard water, you might consider sodium gluconate. I haven't tried it, but many with very hard water report that it is more effective than SC.

Besides using a chelator in the soap, I also squeegee the shower after each use, and follow up with a homemade daily shower spray made of CA dissolved in distilled water. As a result, we have little to no soap scum buildup on our shower.
 

DeeAnna

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I'm sure there are all-NaOH shave soaps out there, but there are very good reasons to use all or mostly KOH for a shave soap. A good shave soap will have a high % of stearic and palmitic acids in it, so it's not a very soluble soap.

The use of KOH does two things -- Potassum-based soap is more water soluble than sodium-based soap, so it will form a lather faster and easier. The KOH also makes the soap physically softer so you can get more soap in your brush or on your face with less effort. Those are big advantages for this type of soap.

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From a strict chemistry sense, a soap with a higher superfat does not create any more soap scum than soap with a lower superfat. Soap scum is the result that happens when "normal" soap (not fat) reacts with hard water minerals (calcium, magnesium, etc.) to form insoluble soap (calcium soap, magnesium soap, etc.)

But you'll hear reputable soap makers say a higher superfat does create more scum in their shower and plumbing. Here's an explanation of why I think this happens --

Normal soap (aka soap based on sodium or potassium) emulsifies fats -- either the superfat in the soap or fats on the skin. When fats are emulsified, they are able to mix with water and rinse down the drain. Soap scum is insoluble in water, so it cannot function as an emulsifier, so soap scum reduces the cleaning ability of soap. The fats in the bath water don't fully emulsify and mix with the bath water and thus cannot rinse cleanly down the drain. The sticky soap scum and any non-emulsified fat will adhere to the shower walls and coat the plumbing. The more superfat you add to soap = soap scum and extra greasy gunk sticking to the bath or shower walls.
 
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