Couple of odd questions

[Jackofhearts]

Hello all!
First off, a quick recap. A couple weeks ago I had 2 of 3 CP batches overheat a little bit on me. Panicked I turned to the collective wisdom of this forum. I was told that the liquid forming on top of the loafs would likely re-absorb and the soap would be fine (It did re-absorb but whether it will be fine remains to be seen).

Given that the recipe (70% lard, 15% OO, 10% CO, 5% Castor) is usually hard within hours of pouring yet the overheated loaves were still soft 2 days later, I figured that the overheating seemed to slow down hardening. This seems to be confirmed in that after 2 weeks of curing the bars are still soft yet slowly firming up (VERY slowly).

On to my first question: Since this soap overheated, are there any effects this will have on the finished soap and will my cure time be affected? (FWIW, I usually cure 4-8 weeks.)

Also, having read some threads recently about differing saponification speeds for different oils has gotten me thinking.

Which led me to question 2: Are there some oils that are known for faster curing in the same way that some oils are known for faster saponification?
Just curious.

Thanks!
Jack

 

[SoapAddict415]

Hi Jack!! Hopefully someone with more knowledge than me will chime in soon. I don't think certain oils can cure faster but I could be wrong. I'm curious about your first question as I also have a soap that's taking forever to firm up. Mine didn't overheat (to my knowledge) but the other batch I made the same day with the same recipe is rock hard. I'm hoping that something in the answer to your question will help me too.

 

[lsg]

Here is some info on what affects the hardness of soap: https://www.soapqueen.com/bath-and-body-tutorials/tips-and-tricks/cold-process-soap-soft/

 

[DeeAnna]

First question --

The cure will take as long as it takes. If your soap is soft, you'll have to give it enough time to firm up sufficiently to be used, and that may add some time to the cure period. Hard to say for sure this will be necessary, but that's what I'd be thinking if it was my soap. There is no surefire certain answer; you'll just have to be patient.

"...I figured that the overheating seemed to slow down hardening..."

I have not known simple overheating to cause softness in my soap. But the emulsion failure (aka separation) that resulted from the overheating could be the source of your problem.

Second question --

Soap is made from fatty acids, not fats, so your second question isn't really accurate. I'm being picky, I know, but it's an important picky-ness, IMO. Your question is more correctly, "Are there some fatty acids that are known to make faster curing soap?"

Fats are the starting point, but they essentially are destroyed by the saponification process. Some fats, due to their smaller molecular size, will generate more heat per gram as they are broken down into fatty acids and the fatty acids converted into soap. That heat release causes a quick rise in temperature. Saponification proceeds faster at higher temperatures, so batches higher in these fats will tend to saponify faster.

As to whether soap higher in some fatty acids will cure faster than others, I don't have an answer. You'd have to test soap made from pure fatty acids to begin to answer this question in an objective way. As far as subjective opinions go, I don't know that I've seen anyone claim that soap made from, for example, lard (higher in palmitic and stearic acids) cures any faster than coconut oil soap (higher in lauric and myristic acids). Or vice versa.

Even if there was a difference in cure rate, I know a blend of these two fats makes a superior quality soap compared with soap made from either fat alone. So a faster cure for a single-fat soap wouldn't motivate me at all to change my recipes.

 

[Jackofhearts]

DeeAnna, as always your posts are very informative and helpful. It's true that I mean to say fatty acids and not oils. Seeing as how this is simply an idle curiosity, I won't be attempting to isolate fatty acids to test any time soon.

It's good to know that overheating won't, necessarily, affect the hardness of my bars. Although it does concern me considering these bars are still soft-ish while some soap I made a week later using the same recipe are quite hard. The "overheated" bars appear to have fully gelled yet don't look any different. Is separation something I would be able to see?

Thanks! Jack

 

[Iluminameluna]

@Jackofhearts says:
<q>It's good to know that overheating won't, necessarily, affect the hardness of my bars. Although it does concern me considering these bars are still soft-ish while some soap I made a week later using the same recipe is quite hard. The "overheated" bars appear to have fully gelled yet don't look any different. Is separation something I would be able to see?</q>

I too had a "mishap" with a recipe that included some fruit puree AND seawater. It separated in the oven and, panicked, I threw the whole mash in the crockpot. This didn't help in the sense that the soap is STILL hardening after 6 weeks of cure time. The "cooking" of it should've evaporated all, or most, of the water so why is it still somewhat soft, right? And it DID completely gel. Looks almost translucent.

My thoughts, with my limited experience, is that maybe either the sugar in my puree or some other factor, like a higher percentage of a soft oil, with the higher temps from gelling affect the cohesiveness of the soap. I don't know enough about the chemical changes that happen through saponification to come to a clearer idea of why the lack of hardening.

Now I'm scared to use a ripe fruit addition to any recipe. I'm hoping someone with more experience and knowledge sees your post.

Great questions! Wow.

P.S.: I think I might improve on your question about curing times for different oils to my asking if different oils might lead to different curing times. But, it's already known that, for instance, olive oil-based soap (e.g.: Castille) will only be hard enough to last a while and be "good" soap after at least 6 mos. or more, maybe a year if it's pure olive oil. So maybe it's not much of an improvement to your question. Did I confuse that sufficiently?? >,<