Chymification is the conversion of food into chyme, the semi-fluid mass that leaves the stomach for the small intestine. Through churning muscular contractions, acid, and the enzyme pepsin, the stomach reduces chewed food to a thick, acidic slurry over one to four hours, depending on the meal’s composition. Fats and large mixed meals slow the process; liquids pass quickly. Presenting nutrients to the intestine as chyme allows controlled, gradual digestion and absorption downstream. The concept is fundamental to understanding gastric emptying, satiety, and why meal composition affects how long food keeps hunger at bay.