Well, there is this:I have been looking for the recipe for liquid soap but I'm not finding it, Google keeps giving me blogs about people making their soap but I want the original one! Thanks a million!
I don't want to sign up, but I can tell you without reading it that the pharmaceutical method is simply part of a general principle that goes back quite a ways. The principle is to introduce a solvent into the process to facilitate saponification and reduce the needed dilution.I'm not sure it's possible to find the bonafide original recipe for liquid soap. Liquid soap has been around for a long while.
One thing I can say, though, is that the kind of soap that I and some others here make- glycerin liquid soap- was originally an invention of the pharmaceutical profession as a way for them to be able to make their green soap paste in a more quick, timely manner, instead of having to spend the usual hours stirring it at elevated temperatures.
For what it's worth, you can find out a little more about the pharmaceutical glycerin method/recipe by reading silverdoctors posts, starting at post #857 on the following link (you may have to register before being able to see them, though): USP Glycerin Method.