Soap and Glycerin are by-products of saponification. The term saponification is the name given to the chemical reaction that occurs when an oil or fat is mixed with a strong alkali. Soap making has its origins in ancient Babylon around 2500 - 2800 BC.
Although any fats or oils can be used to make soap, we choose Coconut, Palm, and Olive oils. Coconut Oil makes a bubbly lather, creates lots of glycerin and is very stable. Olive Oil has natural antioxidants and its soap makes a creamier lather. Palm Oil is used in place of Tallow of Lard to create a harder, longer lasting bar of soap.
Soap made in earlier times became known as 'lye soap'. That term denotes a harsh soap that would irritate your skin. The fact is that modern handcrafted soap, though necessarily made with lye to get true soap, has no lye in the final product. It has all been reacted with the oils to form soap and glycerin.
Commercial companies remove the naturally occurring glycerin to sell separately for profit. Glycerin remains in Handcrafted Soap to retain its natural moisturizing properties.