Water Activity: Thermodynamics in Food

Water activity is an important thermodynamic concept that is often misunderstood and explained poorly, but can be critical to understanding food preservation, food texture, and other properties. Pathogenic and spoilage microorganisms cannot grow or produce toxins below certain values of water activity, and so maintaining foods below these critical values can become a critical control point.

Water activity is another name for the chemical potential of the water in a system that may include dissol…