purity

Hi! I'm a beginner soapmaker and I'm interested in making liquid soap. The KOH lye I want to use is according to the manufacturer 90-100% pure. That's a 10% difference.. So I'm not sure what percentage to put in the soap calculator? What will happen if I put a too low percentage? What will...

I really tried searching the forum before asking my following question (and I am new here so that could be the glitch perhaps), but I did not find any threads fully discussing this topic. Please help if you can--or direct me to the relevant thread(s). Question. I am trying to research...