While there are people these days who make goat's milk soap, oatmeal soap, and other fancy smelling soaps as novelties and hobbies, there was a time when each family make their own soap.
I have several The Foxfire Book in my research arsenal. These books have all the things settlers and pioneers had to do to survive. Below is the information I gleaned from one of these books about how to make soap.
When fireplaces were cleaned, the ashes were placed in a container that allowed water to seep through. Some had handmade ash hoppers that were made of wood with a paper liner and straw in the bottom to keep the ashes from falling out. The hopper was slanted with a wood pour spout that let the lye drip into the holding container. Water was poured onto the ashes several times during the day and a brown liquid would drip out and be caught. That was the lye used in the soap.
After enough lye has been made, a large wash pot with water is put in a fire and the fire kept hot. In the pot
If a scented soap was wanted this was the time to add the scent.
Most of the soap remained soft and was kept in a hollowed out log and covered with a plank, then dipped out when needed. Due to the caustic nature of lye, wood was the only thing that wouldn’t get disintegrated in a year.
Mutton and beef tallow made harder soap and could be poured or cut into bars.
(Reblog of an earlier blog post)