As far as soaping goes, not really. Pomace might trace a bit faster but its what I use and I have no trouble with it.
Yes, possibly even more since there are more unsaponifiables in it.
- Pomace probably has more unwanted chemical because of the extraction method used
- Pomace has more a bigger acidity value (more free fatty acids floating) that's why it comes to trace faster.
Bigger acidity value would be a positive wouldn't it? Would it help the soap me less alkaline (harsh)?
Acidity value of an oil has nothing to do with the acid value in the PH range of a water based liquid.
You can not meter the acidity value of an oil with ph strips.
If an oil has a high acidity value it means that it has many free fatty acids that lye will saponify instantly (fast acceleration). This phenomenon will not make the soap less alkaline as lye will keep the soap's ph high (9-10,5), range at which the soap works.
Many of the "Mediterranean" olive oils in stores are actually a blend of olive, canola, and grapeseed. You'll need to read the label carefully to make sure it's 100% olive oil.
Now, does this mean that it would saponify more completely, leaving less fats to nourish the skin?
I think that the only thing it can happen with Pomace is for the saponification to be completed sooner reaching a higher peak temperature, making the unmolding and cutting time sorter. The lye discount will not be affected if everything else is equal.
If you want to slow down the saponification speed with Pomace, I would soap cooler, use a whisk instead of stick blender and use a little more water than usual.
There is some controversy on the chemicals used for extraction, some people believe they stay in the soap, other believe they can't survive the lye. Other likes myself, don't really care either way. Soap is on the skin for such a short amount of time, I don't feel its really a concern.