Two approaches to superfatting

Jaaret · Dec 5, 2008

Hello, fellow soapmakers!

I have been making my own soap for almost five years and superfat my soap by discounting the amount of lye by 7-8%. I use only vegetable and nut oils/butters knowing a bit of each will be left in the final bars of soap.

I'm curious if there is a difference in the final bars when oils are added at trace rather than superfatting by the discounting the lye. I've been thinking of making a base soap with a bit more coconut oil and other solid-at-room-temp oils, then adding adding avocado and sunflower oil at trace. For those of you who have used this technique (and I know you are out there), do you find the final bars using the add-oils-at-trace method have benefits different than superfatting by discounting the lye?

Jaaret

topcat · Dec 5, 2008

Hi Jaaret! I am quite a newbie at CP soap making so don't have any real answer for you, other than I have read opinions in favour of each way here on this forum....could it be primarily personal choice? My (very basic) understanding of the saponification process seems to show that the lye doesn't care what it changes, so unsaponifiable components of oils/butters may make more of an overall difference.....? Other than that, I will be happy to keep you company here until other more experienced soapers arrive :lol:

If you go to the top right of this page and click on search you will find many posts and topics on this subject which may help you track down the definitive answer for you

Tanya

IrishLass · Dec 6, 2008

Hi Jaaret and welcome!

With the CP method of soaping, adding any fats or oils at trace in the hopes it will escape the lye monster is just a futile excersise in groping in the dark, as I like to say. :lol:

I learned from a fellow soaper (a chemist who has actually done consistant experiments on handmade CP soap in a lab) that only a mere 5% to 10% of the fatty acids are actually saponified at trace. The whopping 90% or so of remaining saponification happens within the first 24 to 48 hours after the soap has already been poured into the mold, with some minor chemical changes happening even beyond that.

You're truly better off just taking the lye discount up front. To do otherwise with CP is just a crap shoot because lye is an unfeeling equal opportunity saponifier that never takes into account which oils/fats you want to remain unsaponified. With 90% or so of fatty acids still left to be saponified, you just can't ever know for certain which fatty acids from which oils/fats in your formula remain unsaponified or superfatted at trace.

While you can certainly use oils/fats that have more unsaponifiable components in them, it just seems to me like it would be more trouble than it's worth to try to figure out the exact measurements of the unsaponifiables to be able to calculate an accurate enough superfat from them. Maybe someone has done so, but since I don't like headaches all that much, I've steered clear of such calculations. :wink:

The most I can tell you is that the best and most reliable way to really have control over which oils/fats remain superfatted in your soap is to use the HP method of soap-making, where you cook the soap until it doesn't 'zap' anymore. Then you add your superfatting oils of choice, which will remain unsaponified because the lye monster has already been completely satisfied by the heat of HP speeding the process up.

HTH!
IrishLass

Jaaret · Dec 6, 2008

Thank you!

Thank you for the detailed answer. That is exactly what I was looking to learn!

Jaaret

mandolyn · Dec 6, 2008

Jaaret said:
Hello, fellow soapmakers!

I have been making my own soap for almost five years and superfat my soap by discounting the amount of lye by 7-8%. I use only vegetable and nut oils/butters knowing a bit of each will be left in the final bars of soap.

I'm curious if there is a difference in the final bars when oils are added at trace rather than superfatting by the discounting the lye. I've been thinking of making a base soap with a bit more coconut oil and other solid-at-room-temp oils, then adding adding avocado and sunflower oil at trace. For those of you who have used this technique (and I know you are out there), do you find the final bars using the add-oils-at-trace method have benefits different than superfatting by discounting the lye?

Jaaret

The Handcrafted Soapmakers Guild published an article about this in The Saponifier. According to the article, all oils are up for grabs during the saponification process whether added at trace or not. The process isn't picky about which oils to saponify or when. You very likely would be wasting expensive oils added at trace hoping they'd be left unsaponified. All oils are fair game.

You'd be better off saving expensive oils for leave-on products like lotions & creams.