Soap made from pure olive oil, sometimes called Castile soap or Marseille soap, is reputed for its particular mildness. The term "Castile" is also sometimes applied to soaps from a mixture of oils with a high percentage of olive oil.
Lye being dissolved in water for soapmaking.image below โฆ
LYe:
Soap
Both sodium hydroxide and potassium hydroxide are used in making soap. Potassium hydroxide soaps are softer and more easily dissolved in water than sodium hydroxide soaps. Sodium hydroxide and potassium hydroxide are not interchangeable in either the proportions required or the properties produced in making soaps.
"Hot process" soap making also uses lye as the main ingredient. Lye is added to water, cooled for a few minutes and then added to oils and butters. The mixture is then cooked over a period of time (1โ2 hours), typically in a slow cooker, and then placed into a mold.
Household
Bottles of alkaline drain cleaners containing lye
Lyes are also valued for their cleaning effects. Sodium hydroxide is commonly the major constituent in commercial and industrial oven cleaners and clogged drain openers, due to its grease-dissolving abilities. Lyes decompose greases via alkaline ester hydrolysis, yielding water-soluble residues that are easily removed by rinsing.
Tissue digestion
Sodium or potassium hydroxide can be used to digest tissues of animal carcasses. Often referred to as alkaline hydrolysis, the process involves placing the animal carcass into a sealed chamber, adding a mixture of lye and water and the application of heat to accelerate the process. After several hours the chamber will contain a liquid with coffee-like appearance,[7][8][9] and the only solids that remain are very fragile bone hulls of mostly calcium phosphate, which can be mechanically crushed to a fine powder with very little force.[10][11] Sodium hydroxide is frequently used in the process of decomposing roadkill dumped in landfills by animal disposal contractors.[8] Due to its low cost and easy availability, it has also been used to dispose of corpses by criminals. Italian serial killer Leonarda Cianciulli used this chemical to turn dead bodies into soap.[12] In Mexico, a man who worked for drug cartels admitted to having disposed of more than 300 bodies with it.[13]