No problems with SMF calculations - be warned if you are flipping back and forth between NaOH and KOH on SoapCalc, it does not preserve the tick in the 90% purity checkbox. Doh.
I must apologise - you can close this ticket. I've been examining everything and comparing SoapCalc values to SMF values, trying out single oil recipes, etc., trying to work out where the discrepancy lies and it was me. The '90%' box was cleared in the course of re-running the SoapCalc going...
How are you calculating the lye amounts needed for KOH?
I have compared the SAP values that SoapCalc lists for the oils in my recipe and they match the SAP values in SMF. Then I calculated a 500g batch of soap using 100% of each oil, and looked at the lye amount for NaOH, and ran it again using...
There are a few good videos on YouTube showing dual lye shaving soap and sharing the recipes. I've just tried one of the recipes myself (but found a mismatch between SMF calculation for 60% KOH and Soapcalc calculations - I went with Soapcalc and manually calculated the 40%/60% split while my...
I've tried with a 10% superfat and it still calculated the KOH at 66% so the superfat is a red herring. But the calculation still didn't match what I expected.
10% superfat
Soapcalc calcuations:
NaOH = 63.9 x 0.4 = 25.56 (Soapmaking friend matches when specifying dual lye)
KOH = 89.62 x 0.6 =...
What I did was I entered all my oils into Soapcalc and ran the recipe using only NaOH. Then I ran it again using 90% purity KOH. I took each of the lye amounts and multiplied them by the percentage I wanted in the recipe. So I ran the NaOH amount x 40% and the KOH amount x 60%. The NaOH...
I've entered a dual lye recipe with a 40/60 split NaOH/KOH and a 6% superfat.
The recipe calculator calculates the NaOH at 40% but KOH at 66%. It implies the KOH calculation doesn't account for the superfat.