fizzing

Fizzing, also known as effervescence, is the rapid formation of gas bubbles within a liquid, often accompanied by foaming and the steady release of gas. It typically arises when a dissolved gas becomes supersaturated or when a chemical reaction generates gas within the liquid.

Bubbles usually originate at nucleation sites—rough surfaces, impurities, or microscopic gas pockets—where dissolved gas can come out of solution. As bubbles grow, they detach and rise, producing visible fizz. Changes in pressure, temperature, or agitation can trigger or accelerate fizzing; for example, opening a sealed carbonated drink reduces pressure and allows dissolved carbon dioxide to escape.

Common contexts include carbonated beverages, where CO2 is dissolved under high pressure and releases as soon as the container is opened; chemical demonstrations, such as acids reacting with carbonates to liberate CO2; and biological processes like fermentation or catalyzed decomposition of hydrogen peroxide, which produce gases that form bubbles.

Fizzing is distinct from boiling. Boiling involves bulk liquid phase change at a specific temperature, while fizzing is mostly the escape of dissolved gas at or below the liquid's boiling point. The rate of fizzing depends on gas solubility, temperature, pressure, and the presence of nucleation sites.