Champagne bubbles because of a process called carbonation. Carbonation occurs when carbon dioxide gas is dissolved in a liquid, such as champagne. There are a few factors that contribute to the bubbling phenomenon in champagne:
-
Fermentation: Champagne is produced through a process that involves a second fermentation in the bottle. After the initial fermentation converts sugar into alcohol, a mixture of wine, additional sugar, and yeast is added to the bottle. The yeast consumes the added sugar, producing alcohol and carbon dioxide as byproducts.
-
Trapped carbon dioxide: During the second fermentation, the carbon dioxide produced by the yeast gets trapped inside the bottle. The bottle is sealed with a cork, preventing the gas from escaping.
-
Pressure build-up: As the fermentation continues, more carbon dioxide is generated. Since the bottle is sealed, the gas has nowhere to go, causing pressure to build up inside the bottle.
-
Dissolved carbon dioxide: Some of the carbon dioxide dissolves in the liquid, thanks to the solubility of carbon dioxide in the wine. The cold temperature of champagne helps increase the solubility, allowing more carbon dioxide to dissolve.
-
Nucleation sites: Bubbles in champagne form around tiny imperfections or particles in the liquid, called nucleation sites. These can be impurities, dust particles, or irregularities on the glass surface. The carbon dioxide molecules gather and form bubbles at these sites, creating the characteristic effervescence.
When a bottle of champagne is opened, the sudden release of pressure causes the dissolved carbon dioxide to come out of solution, forming bubbles that rise to the surface. The release of carbon dioxide in the form of bubbles is what creates the fizzing or bubbling effect in champagne.