Ingredients 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.
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. This peculiar structure allows soap to adhere to substances that are otherwise insoluble in water. The dirt is then washed away with the soap. We have talked a bit about water solubility but have not really discussed why some things are soluble in water while others are not. Let us begin by talking about the structure of water.