The fluid mechanics of BUBBLY DRINKS

In most cases, the bubbles in a drink are the result of carbonation. The amount of carbon dioxide gas that dissolves in the liquid is proportional to pressure. And if the pressure is suddenly reduced, such as when a bottle of beer is opened, the gas quickly comes out of solution and forms bubbles that rise to the surface, only to burst after a brief instant or to aggregate into a frothy head of foam.