(08-27-2018, 04:17 AM)yohannrjm Wrote: EDIT: One of the issues that may be caused by the addition of a common ingredient like lanolin is incomplete conversion of lye + oil into soap, leaving some leftover lye (which people are sensitive to) or oil.
One easy way to see if it is lanolin that the OP is sensitive to is to get lanolin itself (it is available in lip balms and by itself as a skin care product) and apply it and see what happens.
Lanolin has a saponification value of around 0.075, meaning it's for all intents and purposes non-saponifiable. It won't affect the reaction between the lye and oils at all. It's an additive to soap, not an ingredient used to make soap.
Lanolin in its natural form is a sebum. It's a wax, not an oil. Its use and discovery originally comes from those working with sheep who noticed their hands would be softer after days of shearing and handling sheep. As someone who raises sheep for use in our sheep soaps, I can confirm that my hands are baby butt smooth after days we spend working the sheep.
That said, just like any other thing in life, it's not for everyone. Good thing there are a plethora of options for those looking for good shaving soaps, and we are all allowed to make our own decisions on which soaps we buy.