Soap, what is it really ?
1) Soap is a cleansing agent made from the interaction of fats and oils with alkali.
2) A cleansing agent, manufactured in bars, granules, flakes, or liquid form, made from a mixture of the sodium salts of various fatty acids of natural oils and fats.
Records mentioning the use of soapy materials date from ancient times. Soap making was common in Italy and Spain during the 8th century. By the 13th century, the soap industry had traveled into France. Most soap was produced by using the tallow of goats with beech ash (furnishing the alkali). The French devised a method of making soap from olive oil. In 1783, a Swedish chemist accidentally simulated the reaction that occurs in the present-day boiling process of soap making. He produced a sweet-tasting substance that is now known as glycerin. In 1823, a French chemist discovered the chemical nature of the ingredients used in soap.What's In It ?
Oils and fats for soap are compounds of glycerin and a fatty acid. When oils are mixed with an alkali, they form glycerin and the sodium salt of the fatty acid. The fatty acids required for soap making are supplied by tallow, grease, fish oils, and vegetable oils. The hardness, lathering qualities, and transparency of soap vary according to the combinations of fats and alkalis used as ingredients. An experienced soap crafter uses many combinations of oils.How Does This Stuff Actually Work ?
Most soaps remove grease and dirt because some of their components are surfactants (surface-active agents). Surfactants have a molecular structure that acts as a link between water and the dirt particles. This loosens the particles from the underlying fibers or surfaces to be cleaned. One end of the molecule is hydrophilic (attracted to water), and the other is hydrophobic (attracted to substances that are not water soluble). This peculiar structure allows soap to adhere to substances that are otherwise insoluble in water. The dirt is then washed away with the soap.
Courtesy of http://www.deancoleman.com/whatissoap.htm