Chyme is the liquid substance found in the stomach before passing the pyloric valve and entering the duodenum. It consists of partially digested food, water, hydrochloric acid, and various digestive enzymes. Chyme slowly passes through the pyloric valve and into the duodenum where the extraction of nutrients begins. Depending on the quantity and contents of the meal, the stomach will digest the food into chyme anywhere between 40 minutes and a few hours.