Reversing Saponification

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donniej

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This experiment was to answer the question "can you unsoap soap?" :D

The answer is yes.

Take some scraps and grate them with a cheese grater or cut into small pieces. Mix with vinegar until all the soap is broken apart. You will see an oily layer form on top of the vinegar, this is the soap becoming oil again. The lye is netralized by the vinegar (acetic acid) and becomes sodium acetate (harmless). The relaeased fatty acids reattach to the glycerin and become oil again.

Now heat some water and mix in as much salt as the water will take. Boil the salt water and add some more shaved/grated soap scraps. The soap will curd and float on top, the glycerin will be absorbed into the salt water. Scoop out the curds and wash them with warm water. Mix the curds with vinegar, shaking them in a mason jar works well. The soap is no longer soap, the lye is nuetralized and you now have pure fatty acids. You will notice that they're waxy and don't clean or suds or disolve in water anymore.

I'm guessing you can use these fatty acids to make candles if your base oil was high in stearic acid. Light oils with olenic and linolenic acid will be greasy.

If anyone tries this, let me know how it worked for you.
 

TessC

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Gonna do this with my son as an experiment, thanks!
 

dandelion

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will this take place even after soap has cured?

I wonder this since some soapers say all the lye is "gone" in well cured soap
 

IanT

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donniej said:
This experiment was to answer the question "can you unsoap soap?" :D

The answer is yes.

Take some scraps and grate them with a cheese grater or cut into small pieces. Mix with vinegar until all the soap is broken apart. You will see an oily layer form on top of the vinegar, this is the soap becoming oil again. The lye is netralized by the vinegar (acetic acid) and becomes sodium acetate (harmless). The relaeased fatty acids reattach to the glycerin and become oil again.

Now heat some water and mix in as much salt as the water will take. Boil the salt water and add some more shaved/grated soap scraps. The soap will curd and float on top, the glycerin will be absorbed into the salt water. Scoop out the curds and wash them with warm water. Mix the curds with vinegar, shaking them in a mason jar works well. The soap is no longer soap, the lye is nuetralized and you now have pure fatty acids. You will notice that they're waxy and don't clean or suds or disolve in water anymore.

I'm guessing you can use these fatty acids to make candles if your base oil was high in stearic acid. Light oils with olenic and linolenic acid will be greasy.

If anyone tries this, let me know how it worked for you.
You rock!! :)

Whats your next project!!!??!?!?! Avidly waiting for the next one in the series! :)
 

blueberrylolli

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i've added sulfur in hot process at the end of the cook, which should be more acidic than vinegar, but the soap doesn't revert back to oil?
 

carebear

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and because it's neat. and an opportunity to learn - chemistry lab, but this time in YOUR kitchen and no grade!

more chemistry in action.
 

IanT

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carebear said:
what is the pH of the sulfur?
looked allllll over the place and all i ve found is that it lowers ph but doesnt give an actual PH of the water... hmmmmmm...

if anyone finds it post it! :) now im interested...
 

carebear

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donnie, I thought the same but came across many references to adding sulfur (elemental sulfur?) to soil to acidify it. so wuz confused. still am.
 

Absinthe

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Sulfer will mess up your silicone molds... Does that count as something?
 

IanT

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carebear said:
donnie, I thought the same but came across many references to adding sulfur (elemental sulfur?) to soil to acidify it. so wuz confused. still am.
Yeah same here! I saw a TON of references on that...
 

dagmar88

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carebear said:
donnie, I thought the same but came across many references to adding sulfur (elemental sulfur?) to soil to acidify it. so wuz confused. still am.
yup, that's what we used it for when I used to work at the tomato greenhouse...
Supposedly the sulfur has a chemical reaction with water and can turn into an acidic gas?
 

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