Shampoo vs. Regular Bar of Soap
What’s the difference between a shampoo bar and a regular bar of soap?
The short answer is castor oil.
The two soap recipes have slightly different percentages of oils and a shampoo bar also contains castor oil. Castor oil makes handmade soap lather like that of a commercial soap. You can wash your hair with regular soap, but it won’t get as bubbly and might be a bit more difficult to use. A shampoo bar, however, can be used for hair and everything else.