Glycerin is a byproduct of saponified, hydrolyzed, or trans esterified fats and oils. When recovered in crude state, it is refined by distillation. Physically, glycerin is soluble in water, transparent, colorless and odorless, with a sweet taste and viscous liquid with a high boiling point. Chemically, glycerin is a trihydric alcohol capable of being reacted, but stable under most conditions. Due to these properties, its good compatibility with many other substances, and ease of processing, glycerin is used in many areas.