Soap making is a chemical reaction that involves the saponification of fats and oils with an alkali, typically sodium hydroxide (NaOH) or potassium hydroxide (KOH), to produce soap.
The chemistry of soap making can be summarized as follows:
- Fats and oils are composed of triglycerides, which consist of three fatty acid molecules attached to a glycerol molecule.
- When an alkali, such as sodium hydroxide, is added to the fat or oil, a chemical reaction called saponification occurs.
- During saponification, the triglycerides in the fat or oil are hydrolyzed, or broken down, by the alkali.
- The hydrolysis reaction results in the formation of glycerol and fatty acid salts, or soap molecules.
- The glycerol molecule is a byproduct of the reaction and is often used in other industries.
- The soap molecules are made up of a hydrophobic (water-repelling) fatty acid chain and a hydrophilic (water-attracting) ionic head.
- When soap is added to water, the hydrophobic tails are attracted to each other, while the hydrophilic heads are attracted to the water molecules, causing the soap to form micelles or tiny droplets that suspend in water.
The chemistry of soap making is complex, but the basic process involves the hydrolysis of fats and oils with an alkali to produce soap. By controlling the type and amount of fats, oils, and alkali used, soap makers can produce soaps with different properties and characteristics.