If a recipe is high in myristic and lauric acid (high in coconut oil for example) AND the lye concentration is moderate to high (less water), then the soap batter will probably trace faster. If the lye concentration is lower (more water), a recipe rich in coconut oil is pretty well behaved.
The opposite trend tends to be true for a recipe high in oleic and other unsaturated fatty acids. If the lye concentration is high (less water), then the recipe will tend to trace faster, all other things being equal.
But as
@KiwiMoose pointed out, regular olive oil is slower to trace than pomace olive, all other things being equal. Since the fatty acid profile of both fats is the same per the soap recipe
[email protected], there's something else going on with pomace that affects the rate of saponification. Some say it's the higher unsaponifiable content in pomace, but it also could be the way pomace olive is extracted with the use of solvents.
Recipes that are rich in lard tend to be slow to trace regardless of the amount of water, but palm oil is not as easy going. Since both fats are rich in palmitic and stearic acids, it seems odd that one would be slower to trace than the other.
@Mobjack Bay did some research awhile back that suggested the physical location of the fatty acids in the average lard fat molecule slows the speed at which the alkali (lye) reacts with the fat molecule to make soap.
So I think you can look at the fatty acid profile of a recipe for rough ideas, but I don't think you can't use the FA profile to draw hard conclusions.
