Teach Soap

Hi, everybody!

Well, I'm gathering my supplies (and courage) to give CP soaping a try. I've been doing M&P for about 2 years now, and I've been wanting to try CP for a while. I've been reading as many books and watching as many videos as I can find, and I've been searching through the CP section of this forum to prepare. I'm going to start simply, but I still have so many questions. I'm sure as I go along, I'll come up with even more questions!

Something I've been wondering is how do I determine what the superfat percentage is in a recipe? What I mean is, suppose I see a recipe in a book and I want to run it through a lye calculator to check it or resize it. If I go to a lye calculator, I input all of the oils up front, but I don't know what to put when it asks for a superfat %. I gather that 5-7% is typical, but I don't know what kind of superfat is built into a recipe that I didn't create unless it says what it is (which it usually doesn't).

Is there a way to determine how superfatted a recipe is?

Here's a basic 2-lb. batch recipe I was looking at from Alicia Grosso's "The Everything Soapmaking Book":

Lye solution:
Lye - 4.8 oz.
Water - 12 oz.

Oil blend:
Olive oil - 18 oz.
Coconut oil - 8 oz.
Palm oil - 6 oz.

Superfat:
Castor oil - 1 oz.

The castor oil is 3% of the oils, but surely the superfat is going to be more than 3%, right? I've heard that most recipes have a superfat built in, but how do you know how much is built in? If I go to Summer Bee Meadow's and Bramble Berry's lye calculators and input my olive, coconut, palm, and castor oils with a 0% superfat, the recipe checks out closely, with 4.89 oz. lye/11.41 oz. water and 4.835oz. lye/10.89 oz. water, respectively. But a superfat of 0% doesn't seem right.

Or do I just put in the oil amounts and my desired superfat % and not worry about all of this? I just don't want to end up with too much superfat (or not enough).

I hope I'm making sense. I'm probably overthinking things.

Thanks for any insights!

_________________
- Jenny -
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I plugged your information into SoapCalc and with a 5% superfat the lye should be 4.64 ounces. Does the recipe call for adding the castor oil at thin trace? I don't think you are going to get the full benefit of the castor oil for super fatting as the lye will still be active at trace. Don't know if that answered your question.

Hi Jrose and welcome.

Thanks for plugging in that info lsg.

Jrose: I'm sure all soapmakers will tell you the same thing. It's easier to run your numbers through soapcalc or a lye calculator for your sap values before making soap. http://www.soapcalc.net/calc/SoapCalcWP.asp has a good interactive soap calculator where you can plug in your oils, plug in the superfat percentage you want, then it will do the rest for you. So your current 5% superfat would be 4.64 ounces of "oil X". If you want 8% superfat, then you plug in 8% and the calculator will do the math for you.

If you want a math lesson on how to figure it out manually, let me know and I'll help you understand how to calculate it yourself. I'm not a math teacher, or a native English speaker (Italian), but I can write English fairly comprehensible so I'm sure we can get you to a point where the math makes sense to you.

There is no need to add any oil or butter at trace. The lye is still active at this point and it will take whatever it wants. Add it all up front. For smaller recipes, I would go with 7% superfat.

_________________
Irena
Closed minds are like faulty parachutes; they refuse to open.

Thanks for your replies, everybody!

lsg, I plugged my oils into a lye calculator at a 5% superfat and came up with 4.64 oz. of sodium hydroxide as well. Thanks for running the numbers, too. (I also got 4.593 oz, and 4.65 oz. of lye, too, from two other lye calculators, so I'm wondering if .15 - .21 oz. is significant. I would think it would be, since lye measurements have to be so precise. Maybe the amount of water used explains it? I got water recommendations anywhere from 8-12 oz.)

I guess what I want to know is if there is a way to figure out what superfat % is factored into an existing recipe. It would be handy to know if the recipe-writer figured in a 5%, 7%, or 10% superfat or whatever.

And I agree with you, lsg and soapbuddy, that it wouldn't do much good to add an oil at trace hoping to retain its properties. I know that the lye takes what it wants and it doesn't care whether I added it in the beginning or at the end. I would just add all of my oils up front in the beginning so I don't have to fool around with adding extra things at trace.

And thanks, SuperSoaper, for offering to help with the calculations. I totally agree with you that all recipes should be run through a lye calculator. I would never attempt a recipe without running the numbers first - even if the recipe came from a book, I would double-check it, which is what got me wondering in the first place. It's mostly a question of curiosity because I couldn't get the numbers to agree.

Oh, well, I guess maybe I shouldn't worry about trying to puzzle it out. I guess I should just take the oils from a recipe, input my desired superfat, and go from there. I'll be doing small batches, so thanks for the 7% superfat suggestion, soapbuddy.

Thanks for your input! I do appreciate you all taking the time to help!

_________________
- Jenny -
My soapy blog:
Follow me on my

You're welcome and good luck!

_________________
Irena
Closed minds are like faulty parachutes; they refuse to open.