Im not sure what superfat means, but 9% seems like a lot!
Depends on what oils you're using in a recipe. I use a higher superfat in batches with a high percentage of coconut to make them less drying to my skin. Superfat or lye discount - I tend to use the term 'superfat' but what I'm really doing is using a lye discount. I think I just use the term 'superfat' from laziness. Less letters to type.
Basically, superfat is you're adding extra oil and lye discount is reducing the amount of lye needed for 100% saponification. Example - with 12 oz olive, 6 oz coconut and 6 oz lard, you would need approximately 3.5 oz of lye to completely saponify the oils. (I say approximately because SAP values are only averages of how many milligrams of lye are needed to convert 1 gram of fat to soap.) Because I prefer to have free oil or unsaponified oil left in my soap, I would use a lye discount anywhere between 5% to 20% depending on the recipe.
A 5% lye discount for 12 oz olive, 6 oz coconut and 6 oz lard means I would use 5% less lye than is needed so basically I'm only going to use 95% amount of lye. 3.5 ounces minus 5% equals 3.3 oz. Fortunately, you can enter whatever percentage into SoapCalc (section #4 Superfat & Fragrance) and it will calculate the amount for you.
A 5% superfat is adding extra oil into the batch. 12 oz olive, 6 oz coconut and 6 oz with 3.5 oz lye and I would add an extra ounce of oil to increase the free oil amount by 5% - approximately. :wink:
I hope this all makes sense. If not, maybe someone else can give a better example.
I saw hlee already answered your question about turning into percents so I won't go there. 9% isn't too high depending on what you prefer. I know one member mentioned she always uses 10% SF. I'd actually use a higher superfat for the above recipe since it's low on the conditioning value. But this is only my opinion because I have dry skin. If I only had these three oils to make a batch, I'd use 12 oz olive, 6 oz lard and 6 oz coconut with a 5% superfat since I've found this superfat is what I prefer for soap with 25% to 30% lard in it. It would make a nice bar for the shower.
You have to keep in mind that everyone can only make suggestions about recipes. You have to make it and find out what you prefer for your skin type. I prefer soap with more conditioning oils and a slightly higher SF but some of my family members prefer soap which isn't as conditioning with a lower SF (this is mainly the male members).
@ Chookie2 -
No worries! It's as I've said before - different strokes for different folks. Everyone has their own opinion on what makes for a wonderful soap. There are some members who would never any animal product in soap. I can imagine it now - one of the vegan members seeing this topic and screaming "You're using what?" then swooning across the keyboard. (Okay people...don't get upset with me about this last comment. I saw someone browsing the board and I couldn't resist teasing her. :twisted