ResolvableOwl
Notorious Lyear
I'm intrigued by this somewhat exotic recipe class. I learned about it from Mellen (YT SoapNCrafts: Process | FAQs ). She quotes Catherine Failor's 2000 book “Making Transparent Soap. The Art Of Crafting, Molding, Scenting & Coloring” as a reference. But honestly I have not seen any other mentioning of that technique anywhere. (Someone with access to Failor's book might check this – every recipe I found worked with some kind alcohol – even Kevin Dunn used it).
In essence, it rewards you with a CP (actually CPOP) soap that is translucent/transparent like average M&P bases, but with zero additives, i. e. just from oils, lye, and water – at the price for violating many tried-and-tested soapmaking rules:
Wait, NO SOLVENTS? No glycerol, no sugar, no sorbitol, no ethanol/isopropanol, no propylene glycol? Sounds too good to be true? It is! The downside with respect to proper M&P is that it is, just like any other CP soap, not remeltable. Well, it is “somewhat” remeltable in the sense that it is well-behaved at rebatching.
Of course I had to try it by myself!
HO sunflower as a soft oil. At that high rate of castor oil, its trace-accelerating properties really kicked in, so trace was easy to achieve. Apparently I had some issues with air bubbles and/or silicone rash, but that's superficial enough to be washed away by a sink test
. The clarity is real, similar to a basic M&P recipe. One thing to notice is that the bar on the right is still wet, directly shot after the wash test. I let it dry up, and it already started to become opaque within minutes. So Mellen's warning wrt. wrapping the soaps air-tight all the time is no joke. M&P is much more forgiving (but then, M&P sweats).
From the recipe, I honestly expected that it would never harden up in the first place, and once wet, it'd dissolve into a slimy goo. But no, it really didn't behave terrible at all! The skin feel though wasn't overwhelming. Appreciable lather, but quite stripping, and a tight, chalky skin feel afterwards. No superfat + high coconut + little cure time (tbf I only waited two days, and I don't expect from a CP soap to be super mild after such a short time). And although we all know™ that the processes during curing are essentially independent of water loss/evaporation, I'm not sure if things change much over time. We'll see.
My pet theory is that this 433 CPOP soap is essentially a big blob entirely consisting of one huge glycerin river. High-water batter + strong CPOP in mind. A recipe lacking hard FAs that could contract to form the “islands” between the rivers.
Whoever came up first with the (crazy sounding to the ears of seasoned soapmakers) 433 rule, either put an incredible amount of work into discovering and tuning it, or was a genius. (Or both.)
The “no solvents” property has to be taken with a grain of salt, since there is so much water, plus the natural glycerol of the saponifiaction, and then the ton of ricinoleate (from the castor oil), which itself is an alcohol and can act somewhat like a solvent.
What next?
First off, of course I'd love to hear from others who have made such recipes! I have no conception of the limitations of the 433 recipe methods, its long-term behaviour, and the limits within which things can be tuned. From a gut feel, I'd expect PKO or murumuru to perform superior to coconut. The yellowish colour comes mainly from the castor oil (refined castor, blue dyes, and/or Optical brighteners to a rescue?). Maybe waste the rest of my Cetyl alcohol there?
In essence, it rewards you with a CP (actually CPOP) soap that is translucent/transparent like average M&P bases, but with zero additives, i. e. just from oils, lye, and water – at the price for violating many tried-and-tested soapmaking rules:
- Low lye concentration (~22%), accordingly high water content
- No hard oils (longevity number of her recipe: 7 (!)), coconut as the only source of hardness
- Very high castor oil content (40%)
- Air-tight curing and storage (wrapped up like M&P soap, but not with the aim of preventing sweating, but water loss by evaporation)
- Aim for zero superfat – inconclusive if oils with high content of unsaponifiables are great (avocado) or should be better avoided (olive)
Wait, NO SOLVENTS? No glycerol, no sugar, no sorbitol, no ethanol/isopropanol, no propylene glycol? Sounds too good to be true? It is! The downside with respect to proper M&P is that it is, just like any other CP soap, not remeltable. Well, it is “somewhat” remeltable in the sense that it is well-behaved at rebatching.
Of course I had to try it by myself!

HO sunflower as a soft oil. At that high rate of castor oil, its trace-accelerating properties really kicked in, so trace was easy to achieve. Apparently I had some issues with air bubbles and/or silicone rash, but that's superficial enough to be washed away by a sink test

From the recipe, I honestly expected that it would never harden up in the first place, and once wet, it'd dissolve into a slimy goo. But no, it really didn't behave terrible at all! The skin feel though wasn't overwhelming. Appreciable lather, but quite stripping, and a tight, chalky skin feel afterwards. No superfat + high coconut + little cure time (tbf I only waited two days, and I don't expect from a CP soap to be super mild after such a short time). And although we all know™ that the processes during curing are essentially independent of water loss/evaporation, I'm not sure if things change much over time. We'll see.
My pet theory is that this 433 CPOP soap is essentially a big blob entirely consisting of one huge glycerin river. High-water batter + strong CPOP in mind. A recipe lacking hard FAs that could contract to form the “islands” between the rivers.
Whoever came up first with the (crazy sounding to the ears of seasoned soapmakers) 433 rule, either put an incredible amount of work into discovering and tuning it, or was a genius. (Or both.)
The “no solvents” property has to be taken with a grain of salt, since there is so much water, plus the natural glycerol of the saponifiaction, and then the ton of ricinoleate (from the castor oil), which itself is an alcohol and can act somewhat like a solvent.
What next?
First off, of course I'd love to hear from others who have made such recipes! I have no conception of the limitations of the 433 recipe methods, its long-term behaviour, and the limits within which things can be tuned. From a gut feel, I'd expect PKO or murumuru to perform superior to coconut. The yellowish colour comes mainly from the castor oil (refined castor, blue dyes, and/or Optical brighteners to a rescue?). Maybe waste the rest of my Cetyl alcohol there?