Most of the comments I read suggested a higher percentage of castor than a normal soap (I usually use 5-10%) Could you tell me why you recommend only 5% castor?
I am only a "soap hacker" and there are suitably qualified professionals on this forum with more knowledge than I, but I'll answer based on my experiences:
Castor oil contains an extremely high amount of ricinoleic acid, making for great conditioning, and good bubbly/creamy lather but contains no stearic acid, the acid that provides stability to lather (among other things). In my limited experience, I find a small amount of castor oil goes a long way in shaving soap by providing a conditioning boost, but too much castor makes for less stable lather overall.
Heck, even if you don't nail it please post your progress. I did in my quest to reverse hack a famous vintage soap, still a work in progress. There are some good DIY shave soap threads over on the Soap Making Forum as well.Man alive this site is helpful! I was worried nobody would answer as DIY shave soaps seems a common question everywhere but I'm glad I gave it a go. Thanks everyone who's replied so far, if I manage to nail down a great soap I'll update the recipe and post it.
Then you must report your progress!Thanks for all your help guys! I'll try the recipe suggested by cpacamper and go from there. Just waiting for payday to order the KOH and I'm away