What do you mean by stearic acid spots? If you're talking about the little lumps of harder than the rest of the bar soap, I don't think those are actually stearic acid. I've NEVER encountered them in a shaving soap (and I've done PURE stearic acid batches before), but I got them one time in a batch of body soap I tried doing with almost zero stearic content (castor, olive, palm, coconut and a tiny bit of cocoa butter). I really don't know what they are myself. I assumed they were bits of the cocoa butter I superfatted with (after trace) that for some reason formed bubbles when it solidified, but that was just a guess.