# Sodium Lactate vs. Stearic Acid



## walkinwounded (Oct 20, 2011)

What does everyone prefer to harden a bar of soap, why?

I'm thinking CP.


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## Fragola (Oct 20, 2011)

I use salt instead of lactate, which is difficult for me to find. 

By the way, I also did a small experiment with psyllium. Interesting to try.

Stearic acid has the hassle of needing to heat the oils. But it's easy to formulate (you can enter it in the lye calculator), and it gives you sexy bubbles ! Also, it seems to speed trace, and I am a slow swirler 

For salt, I don't know how much to add. There is no salt calculator which tells you how much to add to bring the hardness from 25 to 35. From what I see, most people use 1-2 t/ppo, but different recipes need different amounts. And too much kills the lather. The big advantage is that you can add it after soap is done, to "fix" a softie (I mean by pickling it).

Anyway, my conclusion sofar is using both: 1-2 t salt and if it's not hard enough, I also add stearic acid. Or simply tweak the recipe (many oils like palm or coconut make a hard soap).


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## judymoody (Oct 20, 2011)

I use cocoa butter.


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## soapbuddy (Oct 20, 2011)

Too much stearic can make your soap seize. I use sodium lactate in every batch.


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## walkinwounded (Oct 20, 2011)

Soapbuddy, do you find a difference in how the soap feels and acts (sudz, bubbles, lather) between the stearic acid and sodium lactate?


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## soapbuddy (Oct 20, 2011)

walkinwounded said:
			
		

> Soapbuddy, do you find a difference in how the soap feels and acts (sudz, bubbles, lather) between the stearic acid and sodium lactate?


The stearic seems to add more stable bubbles. The SL just makes a harder bar.


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## Bubbles Galore (Oct 20, 2011)

I use SL in (nearly) every batch.  :wink:


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## Soaplady22 (Oct 20, 2011)

I use sodium lactate also -- but I use a combination of hard oils to give me the firm base to begin with.


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## carebear (Oct 20, 2011)

I've not found salt to do much - or anything - unless I'm adding so much it's a salt bar.

I asked Dr Dunn (Caveman Chemist) about it and he says that the role of salt in hardening soap is no longer relevant; that it was once used because soaps were made with potassium-based caustics (wood ash lye) and the addition of salt allowed some of the potassium soaps (soft) to convert to sodium soaps (hard).

Now that we use sodium hydroxide it's obviously not playing that role, and really no role at all.


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## Lindy (Oct 20, 2011)

One thing about Stearic is that it can reduce your conditioning properties and make the soap a little more drying.  It does definitely increase the denseness of the lather.


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## walkinwounded (Oct 21, 2011)

Lindy said:
			
		

> One thing about Stearic is that it can reduce your conditioning properties and make the soap a little more drying.  It does definitely increase the denseness of the lather.



Lindy,

Thats what I kinda found with the stearic acid, it was more drying, but was not entirely sure this was the case, so it nice to hear that it was not my imagination. I also read that sodium lactate is a Humectant, a substance that absorbs or helps another substance retain moisture. So by the sounds of everyone else, sodium lactate has the upper hand. Granted stearic acid creates a more stable, creamier lather.


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## Fragola (Oct 21, 2011)

Hmm, never crossed my mind that it might be drying. Probably because the 3 recipes where I used it resulted in a nice conditioning bar.

However, I find harder soaps more drying, simply because of the hardness. In the sense that if you rub a soap brick into your skin, you will end with a drier skin. 



> Granted stearic acid creates a more stable, creamier lather.


To me it seems it aims for bubbly rather than creamy, and the WSP calculator seems to agree. 

I also found out today that bubbly is the opposite of creamy


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## walkinwounded (Oct 21, 2011)

Fragola said:
			
		

> > Granted stearic acid creates a more stable, creamier lather.
> 
> 
> To me it seems it aims for bubbly rather than creamy, and the WSP calculator seems to agree.
> ...



Fragola, you are absolutely right, I also found out lately that they are very different, and I meant to say it produced more stable bubbles rather then creamier.


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## Lindy (Oct 21, 2011)

I found if I'm using Stearic then I up my SF to keep it conditioning....  sometimes I'll add glycerin to it as well with the stearic....


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## Rune (Aug 9, 2017)

Fragola said:


> By the way, I also did a small experiment with psyllium. Interesting to try.



Interesting! What happened when using psyllium? I have a lot on hand, since I use it to regulate my stomach.

I do suspect psyllium would soak up lye water like a sponge, so that the finished soap would have micro sponges of lye encapsuled here and there. But maybe that's not the case?


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## shunt2011 (Aug 9, 2017)

Rune said:


> Interesting! What happened when using psyllium? I have a lot on hand, since I use it to regulate my stomach.
> 
> I do suspect psyllium would soak up lye water like a sponge, so that the finished soap would have micro sponges of lye encapsuled here and there. But maybe that's not the case?


 
This post is from 2011 and many of the posters haven't been her in a long time.  Fragola hasn't been here since 2012.


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## Rune (Aug 10, 2017)

Oops!  I didn't see the date of the thread, sorry


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## ChrisVerdiCuck (May 18, 2021)

I like to use 1 percent stearic acid just to form my bar up


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## The Efficacious Gentleman (May 19, 2021)




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