Kosher gelatin. Gelatin is a protein derived from animal collagen, usually from cow or pig skin and bones. In order for a food to be classified as kosher, the ingredients, preparation and processing facilities must all meet kosher standards. Gelatin is a commonly used gelling agent in foods and can also be used to form hard or soft gelatin capsules for oral products 1. Gelatin is approved for use as a food additive by the U.S. Food and Drug Administration (FDA) 2.