Deciding which oils to superfat

[GeorgeM]

I am new to soap making and I have been experimenting with different recipes. Lately, I was experimenting with olive oil, coconut oil, shea butter, castor oil and hemp seed oil superfatting it at 10%.

I have been using the brambleberry.com lye calculator to calculate my superfat. My question is this: Is there a way to choose which particular oils you want to superfat in a recipe? Or is it just a case of throwing the amount in the calculator and all oils are superfatted equally if you know what I mean? Is there a way to know at which level each oil is being superfatted in a recipe? I am aware that there is a SAP value in each oil. Does that play a role in all this and how are the calculations done to make any conclusions?

 

[Rsapienza]

You can only choose your superfat when doing HP.

 

[GeorgeM]

Ok, I see. Isn't there a formula or a predictable pattern for CP to at least know which soaps are being superfatted first?

 

[Rsapienza]

Ok, I see. Isn't there a formula or a predictable pattern for CP to at least know which soaps are being superfatted first?

Not sure what you mean by "which soaps", but I'm pretty sure the answer is no. LOL

 

[GeorgeM]

Ok yeah, I meant "oils", lol! I guess what I am trying to ask is this: Are all oils you put in a recipe being superfatted equally? Doesn't that depend on the SAP value of each oil?

 

[cmzaha]

No, there is no way to control which oils the lye will use or not use in cp. So if going with cp just add in your superfat % in the lye calculator. In my opinion, 10% is a high superfat. you can control the feel and gentleness versus harshness by making a balanced bar with 20% or less CO.

 

[Saffron]

Hi George, welcome to the forum.

Here is a link to an article by Dr. Kevin Dunn, a good authority on soap chemistry (to say the least), that should answer your question and more.
https://cavemanchemistry.com/LyeDiscount-Dunn.pdf

 

[DeeAnna]

The fats in a particular soap batch aren't necessarily all consumed equally. Some limited lab experiments by Kevin Dunn, author of Scientific Soapmaking, have shown that to be true. But there isn't any way to know what percentage of the various fats remain intact unless you have a decent chem lab and the budget to operate it.

No, it doesn't depend on the saponification value. I can explain why if you want to know, but I'm giving the short version for now in case a short answer will suffice.

edit: Saffron's link will be helpful.

 

[GeorgeM]

Ok, it's clearer now, thanks, everyone!

The article was very interesting:

Key points:

• SAP values are taken as averages and it's not easy to calculate the percentage of superfatting accurately in a recipe.
  
• Discounting the lye or adding superfatting oil on trace is virtually the same thing on CP.

It also concludes that all participating oils are not being superfatted equally. From what I read from the first case of Coconut Oil at 91% and Olive Oil at 9%:

"The blend of coconut and olive oil used to make both soaps contained approximately 7% oleic acid, the remainder being saturated oils. The oils extracted from the discounted and superfatted soaps each contained 22% oleic acid. Thus the unsaponified oil contained more of the unsaturated oleic acid than did the original oil blend. We supposed that the unsaturated oils in olive oil react more slowly with lye than do the saturated oils which predominate in coconut oil. The resulting soap contained a higher-than-expected concentration of unsaturated oil, regardless of whether the olive oil was added at trace."

And it concludes further down:
"The oil component which reacts most slowly with lye will be more concentrated in the unsaponified oil than in the original oil blend."

So, the way I understand it is that, for example, an Olive Oil 50% - Coconut Oil 50% discounted at a certain percentage will contain more of the Olive Oil superfat than the Coconut Oil because of the oleic acid in Olive Oil reacting slower to the lye, even though an accurate amount of superfatting oil can not be concluded.

 

[DeeAnna]

Apply the results from Dunn's experiments to your soap making with some caution. He had to choose very specific blends of fatty acids in order to do his analysis of the fatty acids. If your soap has a different blend of fatty acids, the proportions of the FAs in the superfat could be different. Dunn's tests are suggestive, not proof.

edit: The other thing that a lot of soapers don't realize is that each fat molecule isn't always stripped down to 3 fatty acids and 1 glycerin. One or two FAs can be removed which produce mono- and di-glycerides. Dunn's experiments don't account for this issue, because he had to design a practical experiment that he could do, given the resources available to him.

 

[GeorgeM]

Apply the results from Dunn's experiments to your soap making with some caution. He had to choose very specific blends of fatty acids in order to do his analysis of the fatty acids. If your soap has a different blend of fatty acids, the proportions of the FAs in the superfat could be different. Dunn's tests are suggestive, not proof.

Yes, it seems that way, thanks!

 

[n6561echo]

Hi George, welcome to the forum.

Here is a link to an article by Dr. Kevin Dunn, a good authority on soap chemistry (to say the least), that should answer your question and more.
https://cavemanchemistry.com/LyeDiscount-Dunn.pdf

Hi Saffron, you get my vote for MOST IMPORTANT post of the day! If you don't want to wade thru Dunn's amazing (but laborious) book, this 3 page paper may change the way you at formulating, and processing your soap. There are 3 main takeaways, 1) "the supperfatting hypothesis is NOT supported." 2) There was no difference between the amount of free, unsaponified oils (in the bar) whether taking a lye discount up front, or adding addition oils at trace, 3) Mono and polyunsaturated oil take longer to saponify than saturated oils.
The oils chosen for this study, were "carefully chosen" , for their ease, and specificity of analysis, rather than being a representative sample of oils usually chosen by soapmakers. The only other additional information, I would like to have see, would have be the values taken at 12, 24, 36, and 48
hours. That might have provided information on the rate that specific fatty acids saponify. It does, however, suggest that mono, and polyunsaturated
oils saponify slower than saturated. This raises some interesting considerations in for formulators.

 

[n6561echo]

Ok, it's clearer now, thanks, everyone!

The article was very interesting:

Key points:

• SAP values are taken as averages and it's not easy to calculate the percentage of superfatting accurately in a recipe.
  
• Discounting the lye or adding superfatting oil on trace is virtually the same thing on CP.

It also concludes that all participating oils are not being superfatted equally. From what I read from the first case of Coconut Oil at 91% and Olive Oil at 9%:

"The blend of coconut and olive oil used to make both soaps contained approximately 7% oleic acid, the remainder being saturated oils. The oils extracted from the discounted and superfatted soaps each contained 22% oleic acid. Thus the unsaponified oil contained more of the unsaturated oleic acid than did the original oil blend. We supposed that the unsaturated oils in olive oil react more slowly with lye than do the saturated oils which predominate in coconut oil. The resulting soap contained a higher-than-expected concentration of unsaturated oil, regardless of whether the olive oil was added at trace."

And it concludes further down:
"The oil component which reacts most slowly with lye will be more concentrated in the unsaponified oil than in the original oil blend."

So, the way I understand it is that, for example, an Olive Oil 50% - Coconut Oil 50% discounted at a certain percentage will contain more of the Olive Oil superfat than the Coconut Oil because of the oleic acid in Olive Oil reacting slower to the lye, even though an accurate amount of superfatting oil can not be concluded.

Hi George, you're pretty much right on. I, as well, would like to see this study repeated, using a 5, 10, 15, and 20% lye discount, and results taken at
0,12,24,36, and 48 hours.
s.

 

[GeorgeM]

Hi George, you're pretty much right on. I, as well, would like to see this study repeated, using a 5, 10, 15, and 20% lye discount, and results taken at
0,12,24,36, and 48 hours.
s.

Yeah, I guess the rest of the experimentation is up to us!

 

[n6561echo]

Yeah, I guess the rest of the experimentation is up to us!

Yup! All we need is $100K in equipment, and some graduate students to run all of the repetitive analysis. Ah, to be back in school!

Yes, it seems that way, thanks!

George, Sorry I neglected to include this in my original post. But, to put all of this in perspective (and for those who didn't read the article), keep in mind, that the primary issues, addressed in Dunn's article are 1) The purpose of "superfatting," or lye discounting, is "to cope with the fundamental uncertainty in the SAP values," and 2) according to the "superfatting hypothesis, "some oil remains unsaponified, and that this unsaponified oil consists mainly of the last oil added, usually at trace." (Which he disproves)

 

[n6561echo]

Yup! All we need is $100K in equipment, and some graduate students to run all of the repetitive analysis. Ah, to be back in school!

Yup! All we need is $100K in equipment, and some graduate students to run all of the repetitive analysis. Ah, to be back in school!

Yes, it seems that way, thanks!

George, Sorry I neglected to include this in my original post. But, to put all of this in perspective (and for those who didn't read the article), keep in mind, that the primary issues, addressed in Dunn's article are 1) The purpose of "superfatting," or lye discounting, is "to cope with the fundamental uncertainty in the SAP values," and 2) according to the "superfatting hypothesis, "some oil remains unsaponified, and that this unsaponified oil consists mainly of the last oil added, usually at trace." (Which he disproves)

Ok yeah, I meant "oils", lol! I guess what I am trying to ask is this: Are all oils you put in a recipe being superfatted equally? Doesn't that depend on the SAP value of each oil?

Hi George, I went back and reread some of the posts, related to this issue. Let me see if I can clarify some of the points he made, and why they are important. Keep in mind that this paper discusses ONLY, the issue of Superfatting and the Lye Discount.

1) In paragraph 1, page 2, he states "To cope with the fundamental uncertainty in the SAP value, soapmakers engage in two related practices, lye
discounting, and superfatting.
2) In paragraph 3, pg2, while discusses adding 5% shea oil at trace, he suggests that soapers believe this oil will remain unsaponified. Then, after
describing the details of his experiments, and the reasons he used the oil combinations he did; he gives us the CONCLUSION ( a standard part of
all scientific papers), in which he states: a) "In NO instance was the superfatting hypotheseis supported. b) There appears to be no real difference
between discounting lye and superfatting. The composition of the unsaponified oil, in the finished soap, DOES NOT depend on order in which the oils were added." He suggests that those adding extra oil at trace, appears to be going through a lot of extra, unnecessary work'
3) Lastly, and perhaps most import to soapers, he states, "The oil component (fatty acid) which reacts most slowly with the lye will be more concentrated in the unsaponified oil, than in the original oil blend." What's important here, is that these tend to be the UNSATURATED, mono, and polyunsaturated oils. While these are known to be the conditioning, and moisturizing, they are also the oils most susceptible to oxidation, and the DOS.

The takeaway from this study is: SIMPLIFY YOUR PROCESS, and CHOOSE YOUR OILS ACCORDINGLY .