Crude glycerin is a byproduct of biodiesel production and soap making, consisting mainly of glycerol, but also containing water, fats, and impurities. It has a thick, syrupy consistency and is typically brown or yellow due to the presence of contaminants. While crude glycerin is less refined than purified glycerin, it is still valuable in various industries. It is often used in animal feed, the production of chemicals like antifreeze, and in the manufacturing of soaps and cosmetics after further processing. Crude glycerin can be refined into pure glycerin, which has widespread applications in food, pharmaceuticals, and personal care products. Its versatility makes it a significant byproduct in renewable fuel and chemical production.