Understanding superfat

Soapmaking Forum

Help Support Soapmaking Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

wellysoaper

Member
Joined
Oct 28, 2021
Messages
8
Reaction score
3
Location
nz
Hello, how does superfatting work? I'm doing HP and am using soapcalc, which has an entry for the % of superfat in the recipe, which can be adjusted. Do I stick to the recipe but add the superfat percentage of oils/butter/fat later in the recipe? How do I know how much to adjust? I like to use coconut oil in my recipes, which I know is drying. Is there a way to calculate how much superfat is necessary to compensate for say the amount of coconut oil being added?
 
There is also a topic around "superfat" and "lye discount" which are often the same but can also be very different.

In cold process, they are the same - you use a certain% less lye than you would need to saponify all of the oils (5% less lye is pretty common) and so 5% of the oils do not saponify all things being equal. So you used 5% less lye than needed = 5% lye discount and 5% of the oils are not saponified = 5% superfat.

In hot process you have the option of adding in oils after the saponification process has finished, and here it gets tricky. Because not all oils need the same amount of lye to saponify (which is why the sap values differ) the two terms don't necessarily match up as in cold process, although it's usually fine to still use either term in general.

Are you looking to add a specific oil or oils in after the cook? If not, you can just add everything to the pot and have the lye discount/superfat setting in the calculator set and there won't be an issue.

As for coconut, too much can be subjective - although most people will find anything over 40% too much unless the lye discount is increased. Salt bars use 80% coconut oil or even 100%, but they have around 20% lye discount to compensate (the very high amount on unsaponified coconut oil offsets the stripping effect).

At a 5% lye discount for normal body bars I use 25-30% coconut oil. That might be too high for you (it's higher than some forum members can use) but works for me and my family/friends with my recipe in general
 
coconut oil in my recipes, which I know is drying.
Coconut oil is not drying. The soap made out of coconut oil is.

We don't know what numbers you are aiming for, but let's say you want to have 25% coconut oil in the final recipe, and 5% superfat. When weighing the CO, take off 5% of the total amount of oils and don't mix it with the other oils, but keep it apart. Make your HP soap, which should be at around 0% SF when it has reached vaseline stage. Now you can add the extra 5% CO (along with heat-sensitive additives like EOs/FOs) and melt/stir/dissolve into the HP batter, and glop into moulds immediately.

Now you know that you have 5% SF, of which all is chemically unaltered coconut oil (not drying/stripping/irritant!), and the saponified portion of the oils has 20% CO (a percentage, below which most people agree that the drying effect is tolerable).

Since coconut oil is very oxidation resistant, such a route has the advantage that the final soap is less prone to rancidity/DOS than when you are using fashionable “luxury oils” as post-cook superfat.
 
Coconut oil is not drying. The soap made out of coconut oil is.

We don't know what numbers you are aiming for, but let's say you want to have 25% coconut oil in the final recipe, and 5% superfat. When weighing the CO, take off 5% of the total amount of oils and don't mix it with the other oils, but keep it apart. Make your HP soap, which should be at around 0% SF when it has reached vaseline stage. Now you can add the extra 5% CO (along with heat-sensitive additives like EOs/FOs) and melt/stir/dissolve into the HP batter, and glop into moulds immediately.

Now you know that you have 5% SF, of which all is chemically unaltered coconut oil (not drying/stripping/irritant!), and the saponified portion of the oils has 20% CO (a percentage, below which most people agree that the drying effect is tolerable).

Since coconut oil is very oxidation resistant, such a route has the advantage that the final soap is less prone to rancidity/DOS than when you are using fashionable “luxury oils” as post-cook superfat.

I've been doing 30% CO.

In the Soapcalc app would I then enter 0 for the SF percentage then after saponification add the SF?
 
I've been doing 30% CO.

In the Soapcalc app would I then enter 0 for the SF percentage then after saponification add the SF?
If you enter 0 for the SF, you won't have any SF ... unless you are adding an additional oil that you didn't list in the calculator.

Try using the SoapmakingFriend lye calculator, which allows you to check the box to add the SF after the cook. Once checked, the calculator will tell you how much oil to hold out of the recipe for adding post-cook.

If you are using another calculator without this option, then you would put in your desired SF, and manually calculate how much oil to hold back, based on the total oil weight. For instance, if your total oil amount is 1000g, and your SF is set to 4%, you would add 40g of oil (1000 x .04) to the batter after the cook is done.

You can choose which of the recipe oils to add as the post-cook SF. Of course, as @The Efficacious Gentleman noted, this may cause you to have a slight lye excess before adding the SF, due to varying SAP values for each oil. But since lye purity is almost always lower than the calculator assumes, you should be fine.
 
Last edited:
You can choose which of the recipe oils to withhold and add as the post-cook SF. Of course, as @The Efficacious Gentleman noted, this may cause you to have a slight lye excess before adding the SF, due to varying SAP values for each oil. But since lye purity is almost always lower than the calculator assumes, you should be fine.

This is an interesting point. This reminds me of the superfat vs. lye discount and whether they're different. I've never gotten too deep into the lye discount vs. superfat specific discussions, but now I'm highly interested.

Four results-

0% Superfat, 100 g oil saponified:
Screenshot_20211118-183103-704.png


5% Superfat, 100 g oil saponified, 5 % fat added post cook:
Screenshot_20211118-181148-512.png


105 g oil 5% Superfat (or lye discount?):
Screenshot_20211118-181426-814.png


0% Superfat, 99.75 g oil derived from 105 g oils figured to be each reduced by 5%
Screenshot_20211118-184405-453.png


The "superfat added post cook calc" is basically assuming 100 grams of fat are being fully saponified plus 5 grams of whatever mystery oil you want as the superfat for a total of 105 g fat. This method considers the "superfat" totally irrelevant to the calc.

The "lye discount calc" has 105 grams of fat, but the result is different. How exactly does the lye discount get figured here? The calc simply reduces each oil by 5% to calculate the lye.

Superfat from the point of view of "post cook addition" seems more specific and accurate.

I haven't considered the implications of this, just exploring here.
 
Last edited:
I'm going to expand on this even further thinking on this issue.

Standard 100 g oil 5% "lye discount"
Screenshot_20211118-191820-203.png



These next two results are recipes with "superfats" forced by removing 5% of a specific oil from the calc to get the discounted lye numbers:

100 g oil subtracting 5% for a manual superfat taken strictly from Shea:
Screenshot_20211118-191919-889.png


100 g oil subtracting 5% for a manual superfat taken strictly from coconut oil:
Screenshot_20211118-192315-721.png


At it's most extreme, that's a .27 gram or 2% difference in lye. To me that's pretty significant. We know that certain oils take forever to saponify and others do so instantly. To treat them all the same though in calculating lye discount/superfat, we may have a result that isn't what we intended, either more or less superfat than we planned, and making interpretations that are based on faulty data.
 
Last edited:
Great info and visuals there, @Johnez . I do agree that 2% is significant, although it may still be covered by the lower lye purity than what the calculator assumes.

Yes, and in reality the difference probably would only be half that because they are not picking from extremes like I did. Mostly did it to show there *IS* a difference.
 
@Johnez I recently wanted to test fractionated coconut oil as SF for a 30 oz. oils batch of CP. I brought 95% of the oils at 0%SF to trace, then added the 5% FCO. I was impressed with the result after a 4-week cure. I didn't think the FCO would saponify, and it felt like it hadn't at first, but it did feel wonderful after cure.
 
@Johnez I recently wanted to test fractionated coconut oil as SF for a 30 oz. oils batch of CP. I brought 95% of the oils at 0%SF to trace, then added the 5% FCO. I was impressed with the result after a 4-week cure. I didn't think the FCO would saponify, and it felt like it hadn't at first, but it did feel wonderful after cure.
Do you have an implant in my head or something? I swear I have neither written nor spoke about this to anyone but I've been *dying* to get around to using tht exact ingredient as superfat lol! I was especially interested in it after finding out meadowfoam has almost no major fatty acids-FCO is similar. I suspect most of it's fatty acids are caprylic and capric, though I have not fully investigated. The funny thing is the contribution to cleansing is massive according to SMF, but I'm curious if left unsaponified and as a superfat as to how it performs. People say coconut oil is very nice on the skin (technical term that heh), but of course we know it can be stripping when saponified. Just so many possibilities out there 🤯
 
I was especially interested in it after finding out meadowfoam has almost no major fatty acids-FCO is similar. I suspect most of it's fatty acids are caprylic and capric, though I have not fully investigated.
FWIW my two favorite oils to add to lotions & creams are meadowfoam and FCO. Just a titsch makes a difference. IMO, neither of them make good soaping oils.

FCO traditionally has a long shelf life -- 3 years, if ! remember correctly and as such, makes a good carrier oil for storing essential oil blends.

That being said, I don't trust the values given for FCO on SoapCalc. I used it to make 100% coconut oil LS and it fell totally flat latherwise and cleansingwise compared to regular coconut oil 76°. HUGE disappointment.

What used to be called FCO on LotionCrafter changed to CCT oil (INCI: Caprylic/Capric Triglyceride) to differentiate it from MCT oil (medium chain triglyceride) which is also an FCO and there is one other one that escapes me at the moment.

PS: You may have an implant in your head but I'm not the one who put it there. 😄
 

Latest posts

Back
Top