Essential Oils, Glycerine & Superfatting

[Canuk]

Hi, I'm new to soaping. I've been reading on this forum for a week or so, so I decided to register. I've read 1 book on it, but I'm still puzzled as to when to add essential and fragrance oils, and glycerine. I'm looking at doing hot process soap, and I want to make sure that the process doesn't eat up the fragrance. When would be the best time to add them in the process?

I understand what superfatting is, however, I have yet to understand if essential oils gets turned into soap. And if so, would it count as a superfat?

I'm also looking at probably adding glycerine to the mix. I've read (if I remember correctly), that glycerine will help neutralize the stearic acid. Do you add equal parts glycerine and stearic acid (not the stearic acid from the lye, but added seperately). Also, when in the process do you add glycerine?

I should point out that I'm more interested in the hot process.

If even one of those questions can be answered, I'd be a happy lad.

 

[Cosmo]

I'm going to *try* and answer your questions.

I do not believe the essential oil gets turned into soap, especially with HP. Add these when the soap is in the gel-like cooking stage. Some people describe this stage as looking like mashed potatoes. I'm not very good at HP, so I seem to get all kinds of wonky stages.

I don't believe you should have to add glycerin at all. Handmade soap has loads of natural glycerin content already. Also, I'm not sure why you would add stearic acid to the soap? I know some may do this to make a harder bar. I have never done it.

Also, can you clarify about stearic acid from the lye? Are you adding stearic to the lye?

Maybe someone more familiar with these processes can chime in and help.

 

[lsg]

There should be no problem with the lye eating your e.o.s if you hot process your soap. Cook the soap until it resembles Vaseline in appearance and texture. Make sure the temp. of the soap is lower than the flash point of the e.o.s you are using. I would be careful about adding glycerine, too much can cause weeping of the soap after it sets up in the mold.

 

[Canuk]

Yeah, maybe I should have specified that this is for a shaving soap attempt. That might change the answers a bit

 

[Cosmo]

Oh, ok! That does make more sense. I have no experience with shaving soap. It's on my list of things to try! Sorry I can't help more.

 

[Hazel]

I don't make shaving soap but I add EOs after the lye has been used up and I don't get a zap. lsg is correct about letting the soap cool a little before you add the EOs. If it's not cool enough, the EOs can sizzle and spit which is a bit startling. You can also use less EOs ppo. I use about .5%.

The only concern I have is the EOs might be hard to stir in if you let it cool too much. I'm not sure how stearic acid will affect the stiffness of a cooked batch.

 

[strawberryred]

I understand what superfatting is, however, I have yet to understand if essential oils gets turned into soap. And if so, would it count as a superfat?

An essential oil is not an actual oil, so it does not count towards superfatting, no matter when it's added.

 

[new12soap]

My experience is pretty limited, but I have made one batch of shaving soap and I did it by crockpot hot process. Here is how I did it: Melt all your base oils in the crockpot (or double boiler, or oven-safe pot, whatever you are using). Take a few tablespoons of oil out to mix with your stearic acid (I would strongly suggest melting the stearic acid and tablespoon or two of base oils separately). I used clay, and I sifted in 1 tsp ppo into my oils through a fine mesh strainer. Add lye to oils. Running your recipe through a good lye calculator will account for any superfat or lye discount you enter. Make sure you enter the amount of stearic acid you are adding into the calculator, it will saponify. Stir or stickblend the soap until medium trace, then add the melted stearic acid. It will get very thick very fast, blend it up as thoroughly as possible. Cook the soap until it all looks like something between smooth mashed potatoes and hot vaseline, stirring it up occassionally. The soap should have no "zap" if you tongue test it. Once the soap is cooked, turn off the heat and stir in your glycerin. Be careful, the soap is hot! Once the glycerin is stirred in, the soap will have cooled a little and be a bit more fluid, now stir in any colorants and your EO's. Be careful how much you are using, EO's can cause skin irritation and that is not a good thing in a shaving soap. I used FO. Since in Hot Process the fragrance is added after saponification is complete, you use much less, usually half what you would need in cold process. Make sure everything is fully incoporated, pour (or glop) into your mold.

I have never heard of glycerin neutralizing anything so I can't answer that. Extra glycerin in shaving soap is very good for contributing to a lasting creamy lather, as is the stearic. I did not use equal parts of both, after formulating my recipe and running it through soapcalc, I added enough stearic acid to get my profile up over 20%, and glycerin I added at 10% of my oils.

There is a LOT of very good information on this site about formulating and making shaving soap, use the search box and spend a bit of time reading through the threads and you can really learn a lot

HTH

edited for typo and to add: Everyone who has used my shaving soap has asked for more, I am almost out and need to make another batch

edited again to add that I owe a debt of gratitude to all of the generous soapers here and thru the online community for the success of my shaving soap, so thanks guys!

 

[AmandaJ99]

With hot process soap you shouldn't add the EOs til the batch is totally neutral in Ph. You can use the testing kits for swimming pools, at least that's how I do it, lol. I add my super fatting at the end too when I mix in my EOs. I just kind of muck it all around and then slop it into the molds. My experience with hot process is limited but if you are adding clay for shaving soap I've heard of mixing it with your super fat oil and then adding at end so that the clay doesn't cook. I've only made CP shaving soap so again I'm just repeating what I've heard about the clay. Good luck and let us know how it turns out.

 

[Canuk]

Speaking of lye, I'm looking at making a softer shaving soap bar (not liquid, but not candy hard). Is the answer to mix KOH and NaOH in water? I've only found 1 calculator (summerbeameadow) for both, but it's limited in functions. Or is answer to do more superfatting?

Why would you use both KOH and NaOH?

 

[Hazel]

With hot process soap you shouldn't add the EOs til the batch is totally neutral in Ph.

Handmade soap will never have a neutral pH. Soap is alkaline and will have a pH range of 9-10. If it has a higher pH, it's probably going to feel harsh and drying.

Speaking of lye, I'm looking at making a softer shaving soap bar (not liquid, but not candy hard). Is the answer to mix KOH and NaOH in water? I've only found 1 calculator (summerbeameadow) for both, but it's limited in functions. Or is answer to do more superfatting?

Why would you use both KOH and NaOH?

People use the combination of KOH and NaOH to make cream soap.

viewtopic.php?t=16273
[ame="http://www.youtube.com/watch?v=6IHTkqP21-E&feature=plcp"]http://www.youtube.com/watch?v=6IHTkqP21-E&feature=plcp[/ame]

soaping101 has wonderful videos which are very informative. I do have a few issues with some of the things she shows like using glass to mix lye and using wooden spoons but you'll find her videos helpful since they're very detailed. BTW, she does make a comment about testing with Phenolphthalein and she said the soap tested neutral. Again, you won't get a neutral pH with soap. I've used Phenolphthalein with soap and it's always turned pink. It was driving me crazy. I thought I was doing something wrong until I did a little searching and found out it turned clear in acidic products and pink in alkaline products. This made me wonder why some people said it had to turn clear. I haven't made cream soap (yet) so maybe it does have a lower pH than regular CP. I did find a helpful video about using Phenolphthalein but it looks like I didn't save the link. I'll have to search for it and I'll post the link if I find it.

 

[Canuk]

Is there a calculator that will tell you the amount of glycerin that will be produced in the saponifaction process?

 

[Hazel]

I don't know how the amount of glycerin could be determined except in a lab.

I wanted to correct the info I wrote about Phenolphthalein. I made cream soap today and the Phenolphthalein does turn clear when the batch is finished cooking. I was surprised but I've learned something new today through personal experience. Boy! I feel stupid for not believing other people who stated it turned clear when dropped onto cream soap. But to defend myself, it was always pinkish when I tested regular HP soap. I guess this means cream soap isn't as alkaline as LS, CP or HP. This might explain why I've read comments about the mildness of cream soap as compared to other types of soap.

 

[green soap]

Is there a calculator that will tell you the amount of glycerin that will be produced in the saponifaction process?

You might have to figure this out yourself but it is not hard. Count atoms and determine the molecular weight.

the chemical reaction is (in words)

triglyceride + 3 molecules of (NaOH) ------> (saponification) ------> glycerin + 3 molecules (soap)

This is for a pure soap, lets say sodium stearate as an example. What we get is a combination of soaps from the oils we combine. Even for a single oil, you get a combination of soaps since no oil is made of a single fatty acid, they are all a combination of several fatty acids, or more precisely triglycerides. For sodium stearate for example the formulas are like this:

(CH2)16CH3 OC lNaOOH H2COH2C +3NaOH -----> CHOH +3COHC O H2CC(CH2)16CH3H2CH2C H2C H2C H2C H2C H2C H2C H2C H3CCH2 CH2 CH2 CH2 CH2 CH2 CH2 CH2OHOCOO (CH2)16CH3

Glycerin has this formula: C3H8O3

It is easier to visualize with a 3D representation of the reaction, where you see the triglyceride 'head', which is the glycerol molecule, react with the OH from the Na Oh to become glycerine, while the Na gets attached to each of the three fatty acids in the triglyceride, and you get the 3 soap molecules, which are polar, one side has a Na atom (which likes water) the other side is oil (repels water but likes oil).

To get an estimate, average all your different soap molecules to one average carbon chain length, determine the molecular weight and compare. You can even look it up, goggle for example molecular weight of glycerine, and molecular weight of a pure soap (sodium stearate is an easy one to find). Just remember that you get 3 molecules of soap and only one molecule of glycerine. This will give you an estimate. Add molecular weight of glycerin plus three times the molecular weight of your chosen soap. Now take the molecular weight of glycerin and divide by that total number (glycerin plus 3 soap molecules). This is your glycerin fraction.

You get a greater proportion of glycerin per total soap when you use the shorter chain fatty acids, like lauric acid for example. 12 carbons instead of let's say 18, makes the glycerol portion a greater part of the original triglyceride molecule, so the weight proportion of glycerin that you get from let's say a pure coconut soap will be more than from a pure olive oil soap (18 carbon chains for oleic acid).

The only way is to look at the chemistry, so I hope this helped and has not confused you further.

 

[green soap]

I did a couple of numerical examples because I too was curious about what the fraction was, and I figured this would be clearer.

molecular weight of glycerin: 92.09 (all in grams per mole)

molecular weight of sodium stearate 306.45

molecular weight of sodium olivate 304.44

molecular weight of sodium laurate 222.3

So % glycerin in solid part of soap for a pure sodium stearate soap = 92.02/(92.02 + 3(306.45)) = 9.1% of the solid part of your resulting cold process soap is glycerin. This is if you were able to make a pure sodium stearate soap.

Looking at the smaller sodium laurate molecule and doing the same thing gives us 12.13% glycerin as part of the total soap solids. See? I told you that using all coconut would give us a soap with a greater portion of glycerin, just because they are shorter fatty acid chains, lower molecular weight. Remember that part of the weight of your soap is water, and this varies as the soap cures. This calculation pertains only to the solid (non water) part of your soap.

So here you go, your answer is about 10%. It depends on what fatty acid composition you have, but it will range from 9 to 12%. The only common fatty acid chain even shorter than lauric acid is capric acid, this one is 7% in goat's milk.

So having said all that, and reading that you are trying to make a shave soap, some folks like to add extra glycerin to shave soap, to help with lather retention. Now you know your soap is naturally producing about 10% glycerin, but you might want a little more that that for a shave soap.

 

[judymoody]

I have been working on perfecting my shaving soap for awhile now.

I use glycerine at 10% of my oil weight. The base recipe is a mix of butters and oils with a goodly % of castor. I don't use tallow because I don't soap with animal fats but if that's not a concern for you, tallow is excellent for shaving soap. I also use stearic acid at 5%

This moves quickly but I am able to CP it and get it into the mold while it is still pourable/gloppable. I also use EOs and mix them with the oils before adding my lye. The EOs stick.