What is your preferred neutralizing agent?

[Meshaal]

Hello everyone!
I've been experimenting with liquid soap for about a month now and i'm happy with the improvements that I have made.

However, I'm still not confident with the pH level of my soap. I calculate the lye needed using Soap Maker software.

In the last two batches I have used Boric Acid to neutralize the excess lye. However, it thickens the soap and turns the transparent appearance to a nontransparent creamy color liquid.

In my last batch, for 10 kg total soap weight, I only added 50 g Boric Acid.

Is Boric Acid a good choice? What if I want to retain the transparency of the soap, what neutralizing agent should I use? Citric Acid, Stearic Acid, Borax ..? what is your favorite?

 

[shunt2011]

If you read the long LS creamy Shea post here you will learn there so no need to neutralize liquid soap. So easy and beautiful soap.

 

[DeeAnna]

I agree with Shari (shunt) -- you don't need to neutralize with a separate acid such as citric, boric, etc. If you design a slightly superfatted soap recipe (3% or less of superfat), you'll in effect be neutralizing with fat. Although that's not how most of us perceive superfatting to work, that is its essential effect.

Another key element in this technique is to account for the purity of your KOH. You want to use the correct amount of KOH to sufficiently saponify the fats so the soap doesn't contain too much superfat or any excess alkali. The soap calculator Soapee.com allows you to enter the KOH purity, for example.

edit: But to answer your other questions -- The neutralizers you mention all have their pros and cons. Any of them can thicken liquid soap, because you're creating salts with the neutralization process and salts act as thickeners, especially in high-oleic liquid soaps. And any time the soap thickens, it tends to become less transparent due to the formation of crystals in the soap.

High amounts of stearic acid, whether it comes in the fats or added as a neutralizer, definitely will cloud the soap. A little citric acid goes a long ways, so you can't be in a hurry if you neutralize with citric acid. Boric acid or borax are more forgiving to use than citric, but some people don't want boron-containing additives in their soap.

 

[Steve85569]

Cookies! Cookies are good for almost anything!
Oh. Oops.

 

[Meshaal]

Thank you all for your input. They are all very helpful. I have just tried making one batch without without the adding any acids. I think the fragrance or the preservative also changed the transparency look of the soap. Next time I will pay extra attention which of them causing the cloudiness in the soap.

If you wonder why I used a preservative, it is because I am planning to make a small side business .. so i'm practicing the soap making cycle from A-Z

Thanks again for your helpful comments

 

[DeeAnna]

"...it thickens the soap and turns the transparent appearance to a nontransparent creamy color liquid...."

I read this again and had another thought. If you add too much acid, the result is the soap partially decomposes into free fatty acids (FFAs). FFAs will turn the soap opaque. If this is the situation, you'll probably see the cloudy material eventually separate and form a floating white layer. This separation might take awhile -- days to weeks.

You can add a separate emulsifier to keep the FFAs blended with the main body of soap, or you can skim off the FFAs as they separate out, or you can tolerate the separation and shake up the soap from time to time. If you're selling, options 2 and 3 are viable. Option 1 essentially increases the superfat which might be desirable, but adding the emulsifier is another processing step and additional cost.

 

[gloopygloop]

Many moons ago when I had this problem at the outset of my LS adventures I made up a solution of Koh and added it in tiny increments just until the the fatty layer blended with the main clear soap underneath. It did work and the soap was quite usable for me. it took a while of adding and waiting and adding and waiting until the desired effect was achieved, the waiting I suppose was waiting for the fat to saponify which it did in the end!

 

[DeeAnna]

If you're working with diluted LS, you can add small amounts of dry KOH to the soap to saponify with excess fat or fatty acids. The dry alkali won't dilute the soap further, and there's already plenty of water in the soap to dissolve the KOH. Just stir well and give it time.

 

[Meshaal]

"...it thickens the soap and turns the transparent appearance to a nontransparent creamy color liquid...."

I read this again and had another thought. If you add too much acid, the result is the soap partially decomposes into free fatty acids (FFAs). FFAs will turn the soap opaque. If this is the situation, you'll probably see the cloudy material eventually separate and form a floating white layer. This separation might take awhile -- days to weeks.

You can add a separate emulsifier to keep the FFAs blended with the main body of soap, or you can skim off the FFAs as they separate out, or you can tolerate the separation and shake up the soap from time to time. If you're selling, options 2 and 3 are viable. Option 1 essentially increases the superfat which might be desirable, but adding the emulsifier is another processing step and additional cost.

DeeAnna, many thanks for your valuable input. I will post a picture of the soap without the preservative, with the preservative, with the preservative and acid, just to see the difference that the preservative and acid add to the soap clarity and color.

Many moons ago when I had this problem at the outset of my LS adventures I made up a solution of Koh and added it in tiny increments just until the the fatty layer blended with the main clear soap underneath. It did work and the soap was quite usable for me. it took a while of adding and waiting and adding and waiting until the desired effect was achieved, the waiting I suppose was waiting for the fat to saponify which it did in the end!

This is a great idea. I will try it on a sample of my next batch