Glycerin (or glycerine, glycerol) is a triol or polyol compound. In its pure form, glycerin is a colorless odorless, sweet-tasting, viscous liquid. As alcohol with three hydroxyl groups, it is hydroscopic and soluble in water. Glycerin is a byproduct of three main processes: fat and oil splitting, fat and oil saponification, and biodiesel manufacturing. The fats and oils used can be from animal or vegetable sources.