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calculating actual ingredients?

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Guspuppy

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Is there a soap calc out there that you can put in what you actually put in the soap to find out what the superfat really is? I made my standard recipe for 3% SF this morning but overpoured one of the oils by an ounce. (was out of castor and did math in my head. Not my best subject in school. 😂) I tried soapcalc and SMF but everything seems to require you put in the SF and lye concentration numbers. I can put in what I actually added on soapcalc, but I still have to give it a lye conc # and a SF # before it will calculate? Help?
 

jcandleattic

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You will have to know how much lye it takes to saponify each oil, and then extrapolate from there how much oil to lye you actually used. Once you know those numbers, the calculations should be easy.
 

DeeAnna

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I don't know of any calc that lets you back calculate the superfat. But it's not hard to figure this out even so.

Enter the fats for your recipe as the batch was actually made. Enter an assumption for the superfat -- whatever SF you originally used is a good starting assumption. Calculate the recipe.

You know how much NaOH weight you actually used. Compare the actual NaOH weight with the calculated NaOH weight.

Is the calc'd weight the same as the actual? If the calc'd NaOH is more than the actual, raise the superfat percentage by 0.5%, recalculate, and compare again. If the calc'd NaOH is now less than the actual, lower the superfat percentage by 0.1%, recalc, and compare.

Continue to adjust the superfat percentage and recalculate the recipe until the calculated NaOH weight in the calculated recipe equals the actual NaOH weight you used. That's the superfat in your soap as made.

The lye concentration is moot. It does not change the NaOH weight -- it only affects the water weight.
 
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