Glycerin ("or lack thereof") in dual lye shaving soap

[Fireside]

Does anyone know if skipping the glycerin in a dual lye shaving soap recipe would be a big deal? The recipe I'm going to try is the one from Lovin Soap. The glycerin I have is very old. It might still be okay, though; it doesn't smell funny or look funny. And I can't find any locally...my big box craft store is out and my neighborhood drug store doesn't carry it (someone on here said you can get it at a drug store). But what if I just left it out? Or what if I used fresh aloe vera gel instead (or along with the old glycerin I have, if I decide to use it). I know aloe vera gel isn't meant to be a substitute for glycerin but it would add moisture to the soap, which I think is what glycerin is supposed to do. Thanks in advance for any insight!

 

[AliOop]

Glycerin is extremely shelf stable, so if yours looks and smells ok, I'd use it. It does play a fairly important role in shaving soap, both from a process standpoint, and the feel of the final product.

 

[Fireside]

Thanks AliOop! Do you have an opinion on throwing a little aloe vera gel in (in addition to the glycerin), just for the heck of it?

 

[AliOop]

I've not tried it in my shaving soap, but I could see where it might lend some nice qualities.

Have you made shaving soap before? If not, I'd stick to the recipe for the first time, and make a pretty small batch. That way, you can get comfortable with the process and decide whether you want to change any of the qualities without having to finish up a bunch of the old stuff first. Ask me how I know about that.

Of course, if you are already comfortable with the process of making shave soap, then sure, add some AVJ and see what you think!

 

[Fireside]

Yeah, I was kind of thinking I should just follow the recipe (sans tallow; using other high-stearic butters instead) and see how it goes. I haven't made dual lye shaving soap before. I have made liquid soap a couple times and wasn't real fond of the process. I suspect it'll be the same for this process. But I want to make a shaving soap and everybody says that the dual lye, hot process method is the only way to do it. I've made a cold process soap that I called shaving soap because it made a nice lather that could be used for shaving but it's nothing like what you get with the dual lye formulation. My plan is to use 16 ounces of oils/butters, which is a relatively small batch.

 

[AliOop]

Sounds great!

Do check the total stearic FA number of your revised recipe to ensure that this stays the same as, or pretty close to the original recipe. If it isn't, you can reduce one of the butters and up the stearic acid (that is, stearic acid as a standalone ingredient).

Shaving soap is similar to LS up to the paste stage, but thankfully doesn't require any faffing about with dilution, solubilizing EOs/FOs, blah blah. I think it's fun, but it does move fast, so typically my water is pretty high, to give a little more working time.

 

[Fireside]

My stearic is 42 vs 37 for the Lovin Soap recipe. Strangely, when I put the Lovin Soap numbers into the lye calculator (saponicalc) using a 5:1 water:lye ratio and 5% superfat, as the recipe says, the amount of water and lye it came up with is more than what the Lovin Soap recipe calls for. That's neither here nor there as it applies to my revised recipe, I just found it curious.

 

[AliOop]

My stearic is 42 vs 37 for the Lovin Soap recipe. Strangely, when I put the Lovin Soap numbers into the lye calculator (saponicalc) using a 5:1 water:lye ratio and 5% superfat, as the recipe says, the amount of water and lye it came up with is more than what the Lovin Soap recipe calls for. That's neither here nor there as it applies to my revised recipe, I just found it curious.

The difference is probably from the change in fats used, which changes the total amount of lye needed (due to different SAP values in your butters vs their tallow).

Once you change the amount of lye, that will change the amount of water needed to make the correct ratio.

 

[Fireside]

But I entered the same fats that are in the original recipe (https://lovinsoap.com/2016/10/shave...ye Shave Soap. This shave soap recipe is made) to see how that recipe compared to my revised recipe using different fats (illipe butter and kokum butter, if you're curious) in place of the tallow. So there was no change in fats when I entered the Lovin Soap numbers into the calculator, just a change in the lye and water amounts the calculator required compared to what the lye and water amounts are in the original recipe from Lovin Soap. Could it have something to do with the purity of the KOH?

Again, it doesn't matter in terms of my revised recipe, which uses a couple different fats and a smaller amount of total fats than the original Lovin Soap recipe and which, of course, I ran through the calculator to get my water and lye requirements. It just made me wonder how the Lovin Soap people came up with the water and lye amounts they came up with because they don't match what the lye calculator (two lye calculators, actually) came up with.

Thanks for your help AliOop and for indulging my curiosity. I'll let you know how it turns out when I get around to making it.

 

[AliOop]

Ah, I see what you are saying now; I thought you were talking about the two different recipes.

If you entered the exact same amount of oils, same lye concetration, and same superfat, then It could also be as you say, that they used a different lye purity. Also, some calculators use slightly different SAP values for each oil than might be used in another calculator. All of the SAP values in each calculator are based on averages/estimates, so there is a range, albeit fairly small.

Illipe and kokum sound amazing for your shave soap. I'm definitely looking forward to seeing lather pics and hearing how it goes for you!