Thanks Arkcon!
I wonder why you believe any soap is edible. You're going to have to explain why you think is is so. Soluble soaps may not be particularly toxic, but they do hurt the GI tract, at least a little bit.
I don't mean in large amounts, as in making a meal out of it.
Calcium soaps are standard practice in agriculture as animal feed, to stabilize oils, and to bypass the rumen in cows to supplement calories from fat without interfering with the bacteria in the rumen as oil does. I don't think there's any reason to believe they would be harmful in small amounts for humans either.
In the stomach:
2HCl + Ca(Fatty Acid) = CaCl2 + free Fatty Acid + H2
Neutralizing stomach acid may be an issue in large amounts, although that's the same issue as found with antacids or calcium supplements and isn't a significant problem in small amounts.
Generally, not a problem with saponification. Where do you believe hydrogen is available to hydrogenate the fatty acid, and by what mechanism?
As above, but I don't think the conditions would be right in that case.
I had considered using HCl to liberate the fatty acids from sodium soap in a three step process to get to the calcium soap also (since the reaction from sodium to calcium soap is so slow from just adding calcium ions to a soap solution).
Interesting, given that calcium hydroxide isn't particularly soluble in water, and calcium soaps of fatty acids aren't either.
Water was unnecessary. The (approximately) stoichiometrically mixed paste of slaked lime and oil reacted (exothermically) when heated (slightly over 100°C) and stirred, and solidified into a hard, brittle, insoluble waxy material when cooled (consistent with the expected properties of a calcium soap).
How do you know your calcium soap is oxidizing? How do you test? What oil, in particular, do you start with?
Smell, caustic burnt/plastic sort of odor, and dark color
Sunflower oil. It may have also been an issue with the unsaponifiables. Unsure how to confirm that.