# Denatured alcohol v monoproplyene glycol



## regansoap (Mar 28, 2015)

Simply are these two things the same?????

New to soaping 20 batches under my belt now.  Want to make - well have made a batch of glycerin soap turned out well but is more like crystal than clear.

Would be really thankful for any help.


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## Seawolfe (Mar 28, 2015)

I've only made one batch of clear melt and pour soap. My understanding is you use alcohol for transparent soap, and propylene glycol, glycerin and sugar water for melt and pour. I've read some blogs that made melt and pour with just glycerin, but it wasn't clear.


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## dosco (Mar 28, 2015)

regansoap said:


> Simply are these two things the same?????



Denatured alcohol is ethanol (grain alcohol - the stuff that you can drink) mixed with something poisonous (things like acetone) so that you can't drink it. Chemical formula: CH3CH2OH

Monopropylene glycol and can be used for antifreeze (evidently it is a major ingredient in aircraft de-icing fluid). Chemical formula: C3H8O2.

-Dave


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## galaxyMLP (Mar 29, 2015)

Both denatured alcohol and propylene glycol are in a class of chemicals called alcohols. 

As others have said, denatured alcohol is ethyl alcohol plus something that we can not drink (often acetone or methanol) This is so that it is not taxed as drinking alcohol. 

Clear soaps can be made with ethyl alcohol because the sodium salts of the fatty acids in the bar soaps are soluble in the alcohol and stay in solution even after hardening (a bar contains crystalized salts which make it opaque) 

Technically, you can melt soaps made with ethyl alcohol; however, due to the low boiling point of the alcohol they will not be repeat-ably meltable and after the first time you melt it, some of the alcohol will evaporate and the soap will not be as clear. 

This is where propylene glycol comes in. Propylene glycol (PG) will also produce a clear soap (although sometimes not as clear) and will allow the soap to be repeatedly melted. PG has a boiling point of 370 degrees Fahrenheit. This allows you to melt the soap many times and still retain its meltable characteristics along with its clear properties. 

There are pros and cons to each.


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## regansoap (Apr 2, 2015)

I have so far made two batches of melt and pour they turned out really well accepted colour and fragrance well but we're a sort of crystal they looked lovely but we're definitely not transparent - do I need to wait for a week or two for it to clear or do I need to use denatured alcohol instead of mono?
I will try and post some photos.


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## Seawolfe (Apr 2, 2015)

How are you making your M&P? If clear is your goal, then it should be clear when its first made, I haven't seen any changes since mine was poured and unmoulded. Heres what mine look like, and its looked like this since it hardened The base soap was 50% palm / 30% castor / 20% coconut at only 1% superfat, then once cooked and no zap it was dissolved in PG, then VG and sugar water.  







Edit to add, Im not sure what the difference is between monopropylene glycol and propylene glycol - I'm only familiar with propylene glycol. There is a sweet deal on PG and VG at Essential Depot here: http://www.essentialdepot.com/product/GLYERIN-1-PLUS-PROPYLENE-1.html


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## regansoap (Apr 3, 2015)

Hi sea wolf thanks for your comments mine is like yours on right and left definitely not tranparent like that little beauty in the middle.   The recipe is from diy soaping online - I didn't have castor oil when I made it so soapcalc ed and added veg oil.  Will post picture.


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## Seawolfe (Apr 3, 2015)

Hi Regan - thats all the same soap, the colored one in front is me trying to figure out natural colors - madder root in this case. The "little beauty" in the middle is a 1/4 inch slice, I did as a test because someone (Catherine Failor?) defines transparent soap as one that you can read 14 point font through a 1/4 inch slice. Or something like that. I remember the words "slice" and "font".

And Im not 100% sure my soap stays clear after remelting, I should check that. Or perhaps Im using too much alcohol spray... Im quite new to M&P

Anyroad, I think I read somewhere that the castor oil contributes to the clarity - see if you can find some at the chemists?
Edit to add: Theres some good info on where to find Castor and other oils in the UK here: http://www.soapmakingforum.com/showthread.php?t=53318


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## regansoap (Apr 3, 2015)

Thanks sea wolf I will try my next batch with castor oil I do have some here.  I've also order Catherine Failor's book.


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## Minerva's Curious Physick (Jan 5, 2022)

Has anyone tried Propanediol as a natural alternative to Propylene Glycol? (I'm trying to be strict about using natural ingredients, and I can use It has a flash point of 99.04C instead of Propylene Glycol's 101C, so I wonder if it would still handle repeated remelting better than ethanol. Propanediol: An alternative to Propylene Glycol


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## Minerva's Curious Physick (Jan 8, 2022)

galaxyMLP said:


> Technically, you can melt soaps made with ethyl alcohol; however, due to the low boiling point of the alcohol they will not be repeat-ably meltable and after the first time you melt it, some of the alcohol will evaporate and the soap will not be as clear.
> 
> This is where propylene glycol comes in. Propylene glycol (PG) will also produce a clear soap (although sometimes not as clear) and will allow the soap to be repeatedly melted. PG has a boiling point of 370 degrees Fahrenheit.



I really should've edited out my typos in the above post! And more useful to post the boiling point, not the flash point: 1,3-Propanediol's boiling point is *415.4°F/*213°C, so it shouldn't evaporate while remelting M&P. Essential Wholesale calls Propanediol a natural alternative to propylene glycol (but doesn't sell Propanediol, for some reason). 

I've ordered some Propanediol 1,3 from Lotioncrafter; looking forward to trying it out in M&P. Really expensive, though! Maybe $ is the con of this one.


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## DeeAnna (Jan 8, 2022)

@Minerva's Curious Physick  -- If you want to get decent answers to your question, please start a new thread with an appropriate subject line. Not many people are going to see your new question about propanediol in a very old thread with a subject line that references denatured alcohol and propylene glycol


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## Minerva's Curious Physick (Jan 9, 2022)

THANK you--I'm new to using forums, really appreciate your wisdom!


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## lsg (Jan 9, 2022)

In my experience soap made with alcohol is clear, but does not make good M&P soap.  Soap made with propylene glycol makes better M&P.  You will need other solvents as well for M&P.


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## Minerva's Curious Physick (Jan 16, 2022)

You know, this answers my question, so no new thread needed:




Spotted this at the local natural foods store. Looks like someone’s already using propanediol for all-natural clear soap, but they probably don’t remelt it. If it has a high boiling point, maybe propanediol would work as well as PG, but it's so expensive... I'll use my new little bottle of LotionCrafter propanediol for lotion instead.


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## ResolvableOwl (Jan 16, 2022)

“Propanediol” is an ambiguous name for a compound (no positions given). Wikipedia links to a disambiguation site that links to both 1,2-propanediol (“propylene glycol”) and 1,3-propanediol (“trimethylene glycol”). Either one is rightfully called “propanediol”. From the inscripton on that label, it is not evident which of the two the manufacturer of this soap added.


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## Minerva's Curious Physick (Jan 17, 2022)

Maybe I really should start a new thread for this like DeeAnna suggested, then! Just learned what necroposting is, and looks like I'm totally doing it here.


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