Making pure glycerin

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Hi everyone! First time posting and I’m not sure if it’s even in the right place! Lol apologies if I am!

I am relatively new to soap making but I am looking to extract pure glycerin from soap, like the kind of glycerin you buy to make your own glycerin soap from scratch mixed with alcohol etc.

Now when I Google how to extract and bottle pure glycerin, the results that show are to use
coconut oil,
olive oil,
lye solution,
salt

Now this is probably me just being a noob but could someone please tell me whether this would be fractionated coconut oil or 76 degree coconut oil?

I can’t find the answer anywhere and I would really appreciate any advice or guidance in this process from you lovely soapers who know what your talking about! Lol

thanks in advance!
 
Thank you KimW for replying!
I have just checked that post and it still doesn’t mention which type of coconut oil you should use.

I am beginning to wonder though if it is worth the effort, I just felt it would give my soap an extra touch, that I make and extract the glycerin myself for the final glycerine soap product.

But thank you very much! I might have to have a dig around on here and see if I can find any mention of the answer :)
 
I'm a bit confused what is your goal. Do you want a soap with a lower glycerol content than results naturally from saponification? Or do you want to add extra glycerol to the soap? Or do you want to isolate glycerol for separate usage?

The ingredients in the first post might suggest the former. Search for “salting out”, a technique to make a soap that is low in residual glycerol.
If you want to gather glycerol itself, then the soapy watery brine with a few % of glycerol, that you can isolate from soap, is about the worst mixture to start with. Glycerol is notoriously difficult to clean up (you can't distill it), doubly so with household means. You're definitely better off with just buying commercial glycerol. Unfortunately, many within the DIY scene are quite inconsequential with nomenclature. Yes, the salting-out waste brine contains most of the glycerol from saponification, but that doesn't mean that there is a lot of glycerol (by percentage) in there, justifying recovery – but that doesn't stop folks to call it “glycerol” although it might at best contain some 10% of glycerol, the rest being water, salt, and residual soap.
 
Thank you ResolvableOwl for replying.
I did want to extract glycerin for a separate use.
So really it sounds like a lot of effort for a little to no quality liquid anyway.
I will just purchase it, it seems like the only way to ensure I’m going to be using a quality product.
Thank you very much for your advice! :)
 
Can anyone tell me if the percentage of potential glycerin is variable between oils? Eg olive oil vs coconut oil
 
Yes. The weight of glycerol liberated by the saponification is 0.768 times the weight of NaOH needed. Multiply SAP value by 0.768, or use any soap calculator, enter the oil(s) of choice, set superfat to 0%.

That said, above caveats for the glycerol purification still fully apply. Without industrial equipment, you have just no way to isolate this glycerol.
 
Can anyone tell me if the percentage of potential glycerin is variable between oils? Eg olive oil vs coconut oil
USDA info on glycerin & oils % of glycerin

The glycerin content of most vegetable oils is similar. Coconut oil contains the most. That info is in the USDA link above.

There are MANY reasons to want to know how to extract glycerin from soap making since glycerin is used in so many products and is often made synthetically or with GMO plants and yeasts. Being able to make glycerin at home is valuable knowledge. Glycerin is used in foods, cosmetics, herbal preparations, and many other industries.

And just for soapmaking, it's good to know how to extract some of the glycerin so you can make a harder more cleansing soap. (someone said removing glycerin from soap makes it like Dial soap, which is completely not true. Dial soap is detergent (synthetic surfactant) it's not even soap).
 

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