Just a quick note... stearic acid is almost necessary in shaving soaps due to the stability it adds to the lather; in shaving soap, the cleansing properties mean nothing, the lather is everything.
Additionally, hardness doesn't mean much with a shaving soap... shaving soap is designed to be converted directly into lather, and is left in the bottom of the shaving bowl, with the only water coming from a nice badger bristle brush; it doesn't tend to disintegrate the way that a bar of soap left in a wet soap dish will.
As for sources of stearic acid, personally, I use tallow. If you are specifically working on a cruelty free recipe, you could substitute cocoa or shea butters.
I haven't done much work with directly adding stearic acid into a standard bar soap... but actually adding stearic acid can be tricky, since it will tend to turn to soap on a stick instantly... use a wisk, or even a spatula, rather than a stick blender.
Additionally, as mentioned above, stearic acid needs to be accounted for in the recipe as if it was an oil.
Personally, if I was going to do a bar soap, was going to superfat it, *AND* was going to use stearic acid, then I would run numbers for both the superfat % that I wanted to hit, and for ZERO superfat (and, again, don't forget to account for the stearic acid in both numbers).
This way, you can add the stearic acid directly to the oils, then add you lye, and add the remaining oils at medium or heavy trace.
This lets you be certain that the stearic acid was saponified completely (avoiding those spots), and lets you superfat your bar.
I have been making a fairly soft batch lately or slow to harden I should say. I put this down to the yoghurt I have been using.....one batch forgot to include it in the water amt. My question is I bought some stearic acid and plan to use it at 7 grams per kilo but can't find how to add this to the batch. Do you melt it first in the micro wave with the other hard oils then add to the remaining oils and is there anything I need to take care with. One post here said stearic acid can be difficult to use....how what problems do I need to be aware of other than faster trace ?:crazy:
