How to Make Homemade Liquid Soap - The Spruce Crafts- natural liquid soap recipes ,If you'd like to go beyond the basics of cold process soap making, whip up a batch of liquid soap.It requires a bit more patience to make liquid soap than it does to make bar soap.The major difference between liquid and bar soap is the alkali used to saponify the oils. All soap, whether liquid or hard, starts with a simple chemical reaction between oils and an alkali.How To Make Liquid Soap: A Simplified Process for Natural ...Sodium hydroxide is used to make hard bar soap while potassium hydroxide is used to make liquid soap. Potassium hydroxide is harder to find and comes in flakes, not beads. The flakes are easier to work with, but are still caustic, so gloves and protective eyewear must be used.