History of Soap Making :
It is impossible to deny the influence of soap has had on human civilization. What is unclear is when soap actually became such an important part of everyday human lives. Some theories conclude that prehistoric humans were the original makers and users of soap but some conclude that the Gauls living in what is now Belgium and France are responsible for soap, especially goat's milk soap recipes. Other accounts credit ancient Greeks with using wood ashes(primitive lye) to clean their pots and cherished status of Greek Gods. Roman legends has the origin of soap as accidental. When they sacrificed animals on Mount Sapo, animal fats and wood ashes, guided by rain water, trickled down mount Sapo to the Tiber River where women washing clothes found the mixture to be useful in cleaning their garments. In Africa, wood ashes gathered after cooking in open fires, were mixed with water and used to clean pots and other items before it was discovered that adding animal fats to the mixture was even better. Wood ashes, when mixed with fats or oils, produces a chemical reaction called saponification. This process results in the soaps used every day.
After these discoveries came soap factories. The first one is said to have been in Marseilles, France, where olive oil was used to make what is known as Castile soap, which was all the rage before the introduction of palm and cocoa oils. Nicholas Le Blanc, a French chemist and physician, is credited with revolutionizing soap making by developing the Le Blanc process, an industrial way to produce soda ash, also known as sodium carbonite. He developed the process in 1791 in response to a French Academy of Sciences offer for prize money to the individual who could come with a way to produce alkali from sea salt. James Muspratt, a British chemical manufacturer, introduced the Le Blanc process to England during the 1810s and in 1811 Michel-Eugene Chevreul, a french chemist, identified the exact measurements of fat necessary to make soap, helping the industry and art develop into an exact science.
Today, commercial soap making features advanced technologies. On the other hand soap making at home, follows the unchanged recipe that the Romans might have accidentally discovered : Water, Fat and an Alkali to make Soap.
Cold Process soapmaking is the act of mixing fixed oils (common oils include Olive, Coconut and Palm) with an alkali (Sodium Hydroxide or Lye). The result is a chemical process called saponification, where the composition of the oils change with the help of the lye to create a bar of soap.
Hot Process :
In hot process the saponification process is accelerated with heat. The soap is made similar to cold process soap ~ using oil/fat/nut butters, lye and water. The ingredients are brought to trace. The soap is then exposed to heat and "cooked" through the saponification process, usually in a crock pot or double boiler. At this point fragrance and color added and the soap is place into a mold. The hot process somewhat changes the appearance of the finished soap, but allows the soap to be fully saponified and immediately ready for use within a few days.
Melt & Pour :
This ready-made “soap” comes to the soap crafter in bulk form and is then remelted. Scent, colorants and other extras are added and then poured into molds. Often this type of soap is chosen to achieve a more “artistic” look to the soap. There are non-detergent based M&P bases (similar to CP or HP) and detergent bases. If your soapmaker’s base lists SLS (sodium lauryl sulfate or sodium laureth sulfate) as an ingredient, the M&P is detergent based.
Liquid Soap :
Liquid soaps are pump able or pour able soaps. Liquid soaps are made with potassium hydroxide instead of the sodium hydroxide bar soaps require. Liquid soap can be made with or without synthetic ingredients and, like bar soaps, utilize as many or as few different oils as the individual soap maker likes and can be transparent or opaque, thick or more fluid.
Soap is a combination of Water, Alkali (lye) and Acid (Vegetable Oils or Animal Fats). These ingredients combine to create a chemical reaction called Saponification, which is the spliting of the oils or fats into their two natural parts - Fatty acids and Glycerin. These process neutralizes the alkali and the end result is soap.