Making Glycerin

[bathgeek]

Hi all,

Some of you may know that allergens are a big thing for me when making soap. My friend with the coconut allergy actually has allergic reactions to anything that contains glycerin sourced from coconuts. My own soy allergy is not super strong, but I know some people are allergic to soy-based glycerin. Palm glycerin would trigger nut-allergy folks.

I have been trying to source specific-source derived glycerin for a while and have pretty much given up at this point--the only source-specific glycerin I can find is soy based glycerin, which is being sold online as "kosher glycerin". So I thought, "Maybe I can make my own?" I searched and basically when you salt out soap, the liquid on the bottom is glycerin and the stuff on top is soap (without glycerin). If I used olive oil and lye, then salted out the soap, I'd then end up with olive-derived glycerin, right?

My questions:

1. Wikihow says that I would need to distill the glycerin to remove dissolved salts. If I didn't distill, just used the glycerin as-is after straining out impurities, and used it to make liquid soap, would that mean the liquid soap had salt in it? Salt is a hardening agent... what would that do to my liquid soap?

[Removed question #2]

I've been making the exact same recipe for so long that venturing out of my comfort zone is scary... ^_^;;;;;;;;

 

[Saranac]

I know I've seen corn glycerin somewhere, but I can't remember where, and I can't find it now. I'll keep an eye out for it. As for refining your own... ???

 

[BattleGnome]

DeeAnna has an article on salting out soap. If nothing else there is a proven method for salting out the soap except you have a water/glycerin/salt mess to sort out.

I’ve never made laundry soap but stain sticks are on my short list. The few things I understand from reading: 0% or lower for the SF (there is an Andelusian soap recipe on the forum with a -40%SF that’s supposed to be good for laundry, don’t know about salting it out) and crumble or grate the soap as soon as you can to make it easier on yourself (as far as I know a dedicated cheese grater should do the trick)

 

[SaltedFig]

A link to the topic on salting out for laundry soap, with lots of pictures and good stuff: http://www.soapmakingforum.com/showthread.php?t=52103[FONT=&quot]

The technique is used in traditional soap making (Aleppo, Marceilles)

Let us know how you go.
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[Susie]

You can make liquid soap without using glycerin. You will not get that honey consistency, but it will still work if you thin it down and use a foamer bottle. To get around the "glycerin will help it trace faster", just grate up about half an ounce of handmade bar soap into the hot water/KOH mixture. That speeds trace also.

 

[bathgeek]

You can make liquid soap without using glycerin. You will not get that honey consistency, but it will still work if you thin it down and use a foamer bottle. To get around the "glycerin will help it trace faster", just grate up about half an ounce of handmade bar soap into the hot water/KOH mixture. That speeds trace also.

Sorry, I should probably have specified: I can already make foaming liquid soap, I have a LOT of that (and need the foamer bottles, which I ordered but are slow to arrive). I was hoping to make the honey consistency-type soap. ^_^

Also, I use glycerin in my bubble bath formulations. I'm not worried about extra salt in those, though. I don't think it'll affect them. ^_^;

 

[bathgeek]

A link to the topic on salting out for laundry soap, with lots of pictures and good stuff: http://www.soapmakingforum.com/showthread.php?t=52103

Thank you, I've read that one and a bunch of other pieces on salting out soap. ^_^ No one talks about what to do with the glycerin that is removed, though; everyone talks about the soap. I guess I know what I'll be searching for today (how to distill glycerin). ^_^

 

[Zany_in_CO]

Hi all,
So I thought, "Maybe I can make my own?" I searched and basically when you salt out soap, the liquid on the bottom is glycerin and the stuff on top is soap (without glycerin). If I used olive oil and lye, then salted out the soap, I'd then end up with olive-derived glycerin, right?

I've salted out 100% olive oil castile. What you end up with is "pure soap" in the form of "curds" on the top and brown watery gunk (the "impurities") on the bottom. How much of it is actually glycerin, DeeAnna maybe able to answer that, as well as whether it can be salvaged. I don't know. I always just dumped it down the drain.

If you don't mind my asking, what do you need the glycerin for?

I don't use glycerin in any of my non-soap products. Glycerin is a humectant -- it wicks water from the air and brings it to the skin. When there is no water in the air, as in Colorado's Alpine Desert Climate, then glycerin takes it from the skin. YIKES!

When I first learned this, I tried putting glycerin straight on my skin. It stung like a bee! Then I waited for a rainy day and tried it again. It felt really nice. Ever since then I've been subbing local honey for the glycerin in my lotion & potion recipes. There are other humectants you can use as well.

HTH :bunny:

ETA: I just saw this:

I was hoping to make the honey consistency-type soap.

You can do that without using glycerin. The reason we LS-ers love the Glycerin LS method is the speed with which you can make LS. You can get a perfectly decent LS without glycerin. I do it all the time as do others on this forum.
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[bathgeek]

If you don't mind my asking, what do you need the glycerin for?

I make solid bubble bath bars and glycerin is the humectant in those bars (as well as being a bit of lather stabiliser). ^_^ I don't think honey would work too well in those bars... plus honey would introduce yet another allergen (anyone allergic to bees would have to stay clear).

I also want to make _thick_ liquid soap without having to deal with other thickeners. I already have beautifully transparent liquid Castile soap, but the consistency is VERY thin and it works best in foaming soap. People just aren't used to soap coming out of a pump bottle being that consistency. Foaming bottles are expensive, though, so I wanted to try using glycerin to thicken the liquid soap and offer a regular non-foaming liquid soap.

 

[Saranac]

I haven't had any luck finding the corn glycerin. Now that I've slept on it and had my coffee, I <<think>> it was at SaveOnCitric.com, and it may have been a closeout item.

You might also look into Propanediol which is a corn-based replacement for Propylene Glycol. I haven't tried it as a replacement for glycerin in GLS, so I don't know if it will provide the same results. I have some in my shop; if (and that's a big "if") I get a chance this week, I will give it a try. Unless someone has a compelling reason why it won't work. . . .

Propanediol is a good humectent and it supposedly improves the function of preservatives; I've only ever tried it in MP soap and deodorant.

 

[Saranac]

I already have beautifully transparent liquid Castile soap, but the consistency is VERY thin

Salt (NaCl) should be all that you need to thicken a true (high oleic) Castile.

 

[Zany_in_CO]

Salt (NaCl) should be all that you need to thicken a true (high oleic) Castile.

DITTO ^^^ Head over to Brambleberry, find the Liquid Castile Soap Base. There you will find a description of how to thicken Castile LS with Salt.

ETA: https://www.brambleberry.com/Natural-Castile-Liquid-Soap-Base-P4609.aspx

Special Tip: You can also use .5 oz. table salt (very important it be plain table salt, just the cheap stuff) dissolved in 1.5 oz. distilled (warm) water to naturally thicken the soap prior to adding fragrance. We use about 12 ml of the salt solution in 16 oz. to get a very thick soap. Give it a try!

 

[Saranac]

Foaming bottles are expensive, though, so I wanted to try using glycerin to thicken the liquid soap and offer a regular non-foaming liquid soap.

Before you write-off foamers based on the price of the bottles. . .

I sell both pumps and foamers, and it cost me less to put together an 8 oz foamer bottle than it does an 8 oz pump--even though the foamer bottles are more expensive. Keep in mind that even with the glycerin, your thick soap is going to need a higher concentration of soap than a foamer bottle (unless you thicken it with salt). And the more "actual soap" in the bottle, the more it cost.

It all comes out in the wash!

 

[Saranac]

Okay--I looked at my calendar and realized that if I didn't try the Propanediol Liquid Soap (PLS) today, it'd be next week before I had a chance. Luckily, it came together REALLY quick. From starting with Soapee.com to the finished "paste", it took all of 40 minutes (if that). The formula is attached, but I made 1 change. The 270.7 g of Total Water Weight was 1 part water (90.2 g, to dissolve the KOH), and 2 parts Propanediol 1,3 (180.4 g)

It came together quick (once everything was mixed, I heated it up to about 140F), but with none of the stages I'm used to seeing, just an ultra thick liquid soap and flying bubbles.

It took some time for it to even show signs of thickening while cooling. In fact, I still had a nice gel-like product at about 120 F. I've played with propanediol before (in scratch MP soap and NaStearate deodorant), and I remember those products still being fluid at about 120F. A small sample of the PLS gel on a cold plate firmed up into a very sticky paste.

This recipe is a deviation from my norm, so I'm sneaking up on the dilution. Right now I've got 125 g of paste with 75 g of water. What has dissolved is very clear (more so than what I normally make), and a nice pale yellow color (I'm used to using rosin in my GLS so it's been a while since I saw this color). Only time (and cooling) will give me an idea of the finished clarity.

I tried some of the paste and it lathers very well. The propanediol is such a great humectant that my washed, rinse, and dried hands stay "moist"; from the humidity.

While I <<think>> this is working, propanediol is rather expensive compared to glycerin (EssentialWholesale.com has it for about 4x the price of glycerin from SC).

 

[bathgeek]

Ouch. That’s expensive. Though I guess not as expensive as SLSa.

 

[bathgeek]

So my “need glycerin for LS” thing really isn’t a need if I experiment with salt. I’m going to try it! But then I still need to derive glycerin for the bubble baths...

 

[Saranac]

So my “need glycerin for LS” thing really isn’t a need if I experiment with salt. I’m going to try it! But then I still need to derive glycerin for the bubble baths...

As long as your LS is formulated with a high amount of oleic acid (and at the same time, not too much coconut or castor), salt should thicken it beautifully. It might take some trial an error, but you'll get there. My current recipe is 60% HO sunflower (with the rest being coconut, castor, and rosin), and if I keep the concentration of soap high enough, it will thicken with salt.
I'm not sure if you're familiar with the Salt Curve, but (as the name suggests) salt thickens on a curve. The more you add, the thicker the LS will become, until it hits the top of the curve. After that, additional salt will only thin it down. Go slow, take notes and you'll figure it out. And if all else fails and you over salt (and the LS thins), you can mix in unsalted LS to get it thickened back up.