Can anyone explain the "Superfat % should be 1/2 of the Cleansing number" rule?

[RuthG]

I make soap for eczema and psoriasis I am superfat at 30% to 35%. I really don't understand the 5% math thing. My calculations was always above 5% and family and friends say that the soap is lovely.

so IDK.

it's all too confusing at 5%

 

[paradisi]

To play Devil's Advocate for a moment : seems likely to me, knowing plumbers (and cooks) over a lifetime, that washing cooking dishes, things like pans with bacon grease, would do a lot more to clog pipes than a few % more or less superfat in soap.

 

[DMCC]

So I'm not alone in being skeptical and puzzled.

The usual default of 5% superfat seems to me to be a more useful starting point for most recipes. A 5% superfat starting point has fewer exceptions to the rule than this other idea.

For example, the "1/2 of cleansing" rule would say we should be using a superfat of 33% for a 100% coconut oil soap, rather than the 20% superfat that many people use. It would say one should use zero superfat for a 100% olive oil soap. Neither makes sense to me.

And, yes, Ali -- even for a more middle-of-the-road recipe, it's going to call for more than double the superfat than the 2-3% that you and I use.

What does your fatty acid composition look like for a 2-3% superfat?

 

[DeeAnna]

What does your fatty acid composition look like for a 2-3% superfat?

The recipes I use are nothing out of the ordinary. Whatever recipe most people would make with a 5% superfat. I'd just set it up with a 2-3% superfat instead.

My personal calc also corrects for NaOH purity, so my superfat is closer to a true 2-3% than recipes calculated by most online soap recipe c@lculators.

 

[DMCC]

The recipes I use are nothing out of the ordinary. Whatever recipe most people would make with a 5% superfat. I'd just set it up with a 2-3% superfat instead.

My personal calc also corrects for NaOH purity, so my superfat is closer to a true 2-3% than recipes calculated by most online soap recipe c@lculators.

Thank you. I can’t go lower than 5% with my recipes. This is after many hours on SoapCalc and Soap Making Friend. I need to play around and reformulate to see what a 2-3 % superfat looks like.

 

[AliOop]

Thank you. I can’t go lower than 5% with my recipes.

I'm curious as to why you don't believe you can go lower than 5%. I lowered mine from 5% to 2-3%, and not one of my users even noticed, let alone complained.

 

[A-Polly]

Thank you. I can’t go lower than 5% with my recipes. This is after many hours on SoapCalc and Soap Making Friend. I need to play around and reformulate to see what a 2-3 % superfat looks like.

One thing to keep in mind is that changing the percentage of superfat doesn't affect the numbers displayed on soapcalc at all. The fatty acids, quality numbers, iodine, INS, and Sat : Unsat ratio remain the same no matter what superfat is chosen for any formula. The lye amount and liquid amount change, but not anything else. It takes experimentation to find what superfat best suits you and the kind of soap you want to make, how you like it to perform with your household water, how it feels on your skin, and so on. It's such a personal thing, and different for all of us!

 

[DeeAnna]

One thing to keep in mind is that changing the percentage of superfat doesn't affect the numbers displayed on soapcalc at all....

Yes, that's very true ... I appreciate you bringing this up. Many people don't realize this.

 

[DeeAnna]

Thank you. I can’t go lower than 5% with my recipes. This is after many hours on SoapCalc and Soap Making Friend. I need to play around and reformulate to see what a 2-3 % superfat looks like.

So you don't feel you can just pick a favorite recipe and set the superfat to, say, 3% rather than whatever superfat you'd been using previously? That's really all I did.

I think I used 3% for quite awhile then dropped to 2% on a whim and have left it there since.