For quite a few years now, I have been making home made soap (soap bars with sodium hydroxide). The only reason I do that is that I find it to be such a fun hobby.

I use coconut oil, olive oil, shea butter, cocoa butter and castor oil. I always superfat it 15 to 20 %, so that means that 15-20% of the oils is in excess to the amount that would be saponified by the lye. This is far more than the recommended percentage (usually 5%) but never had a problem other than the soap lasts much less time.
I don't use colors other than parsley powder.
I cook the soap batter in a double boiler for 3 hours, then stir it, and test it with phenolphthalein (if the drops are clear, I remove it from the heat). Then add a few table spoons of glycerin and sometimes colloidal oatmeal.
I do not have a way to test the pH of the final soap though.
I know with lye based soap it is impossible to keep the ph at 7 since that is the ph of water, and lye is added.
I read in the skin care course that harsh soaps will damage the skin especially as we get old.
I am wondering if my home made soap would damage the skin as much as commercial soaps do, even if I superfat it so much and add glycerin?
(I am starting to think that I may have to find a new hobby! )
Thank you!!

BTW I tried adding lactic acid in the past, at the end of the soap making process, but that causes the soap to break down in a liquid / jelly mess

Dear Rossana:

Thanks for keeping us up-to-date with your soap making endeavor!

Glycerine is a component of many skin-beneficial lipids. So it might be a good idea to make sure your mixture contains it. Glycerin also improves skin moisture levels by attracting water to the skin. This is a vital factor to produce a cleanser that does not dry out sensitive or mature skin.

You can take a close look at the ingredients of Dr. Pickart's Face & Body Cleansing Bar or Liquid to see what he allows into his formulation.

Remember an effective cleanser should truly cleanse the skin without stripping it of skin-healthy proteins and lipids. The ingredients should be simple and short .

Best Wishes,
-Skin Biology