Can of shaken fizzy drink being opened. Fizzy drinks contain carbon dioxide which is injected into them under pressure at a low temperature when the drink is packaged. The solubility of gas decreases as the fluid warms up, but it stays dissolved because it is under pressure. When the pressure of the packaging container is released the carbon dioxide begins to leave the solution in the form of bubbles. If the can is shaken or dropped just before opening the gas is released from solution at a far higher rate causing the drink to overflow or even spray out.