States and Function of Water in Cooking
The Culinary Institute of America
Water is the primary substance in most foods. Fruits and vegetables contain up to 95 percent water; raw meat is about 75 percent water. At sea level, pure water freezes (becomes solid) at 32°F/0°C and boils (turns to water vapor or steam) at 212°F/100°C. Boiling leads to evaporation, which makes reduction possible.
Water is a powerful solvent. Many vitamins, minerals, and flavor compounds are soluble in water. When salt or sugar is dissolved in water, the freezing point is lowered and the boiling point is raised. An important aspect of solutions is their pH, which is a measure of their acidity or alkalinity. Pure water, which is neutral, has a pH of seven. Anything above seven indicates an alkaline (basic) solution; a pH below seven indicates an acidic solution. Practically all foods are at least slightly acidic. The pH of a solution affects the flavor, color, texture, and nutritional quality of foods.
Reprinted by permission from The Culinary Institute of America, The Professional Chef, 8th Edition (John Wiley & Sons, Inc. 2006).