I make soap using a reliable modern calculator. The only time I do not get complete saponification of the oils is when I voluntarily and purposefully choose to use a superfat.
I'm not talking about a goal, a preference or an opinion. I'm trying to point out where you uncharacteristically have your facts wrong.
There is NO difference between your lye calculations and Failor's. There is no such thing as a "modern, reliable calculator."
1000 g oil
20% coconut is 200 x .183 = 36.6 g NaOH
80% palm is 800 x .142 = 113.6 g NaOH
Total 150.2 g NaOH
That's how I figure it, how Failor figures it, and how YOU figure it. There's nothing more modern or accurate. So when you say that the book is outdated because we have reliable
lye calculators now, those words make no sense.
Failor calculates a lye excess because she wants to ensure complete saponification, while you don't calculate a lye excess because you don't care about complete saponification -- or if you do care then you're going about it the wrong way because your
lye calculator doesn't do that.
The SAP value of coconut oil is normally between .178 and .188. The SAP value of palm oil is normally between .135 and .146. What are your oils? You don't know, I don't know and the
lye calculator doesn't know. That number I just calculated for no lye discount could be -- and likely is -- off base depending on the real SAP values of my oils and how pure and fresh my caustic is. Calculating a so-called "0% superfat" can still result in a significant superfat or lye excess. That's why lye discount is a better term.
That is the exact and only reason Failor calculates a lye excess to ensure complete saponification. That's why your claim to know if you have complete saponification is mistaken. Your
lye calculator is only estimating. And that's why we calculate a lye discount when making soap. Not to get 5% residual oil in the soap, but to get more than 0%.
So yeah, current techniques are simpler and work and maybe are best, but it's just a different approach. And lest we feel too superior, what has taken root now is dissolving KOH in glycerin (not saying that you do it), which is ridiculous.
It's just crazy to heat glycerin to 200-250 degrees, add KOH flakes that threaten to make it boil over, and turn it into a solution that's both scalding hot and highly caustic. You can take that same amount of glycerin and combine it with 50% concentration lye instead of straight KOH and it works exactly the same way.
Adding a solvent to the saponification process is a good idea though. Failor has an analogous solvent method that uses alcohol, but glycerin or propylene glycol are less trouble. So that's an improvement.
