Anxious to read! I’ve been wanting to try soap making. Some old recipes I’ve discovered include instructions like floating a fresh egg in the lye to determine its readiness. I’ve become more fascinated with the history of it than making it lol!
If you use sodium hydroxide or potassium hydroxide you will not have to float an egg. You will be able to calculate how much of either you need to saponify the oils you use. Making lye from wood ash is a good way to end up with lye heavy soap. The soap will also be very soft compared to the hard bars you get with NAOH. KOH makes liquid soap.
You can find sodium hydroxide at ACE hardware (if you are not planning on buying in bulk) under the brand name Rooto. Be sure the label reads 100% sodium hydroxide NAOH. Lard is a great fat to use for soaping. Use a combination of lard, olive and coconut for a hard bar with lots of lather.