How Does
How Are Drinks Carbonated?
Mechanics
-
Carbonated drinks are among the most popular class of drinks on the planet. They're made by dissolving gases, such as carbon dioxide, into a base liquid such as water or sugar syrup. When a gas contacts a liquid medium, the gas naturally dissolves into the liquid until it becomes saturated. The gas will continue to dissolve into the liquid until the pressure in the liquid is equal to the pressure that pushes down on the liquid. In order to dissolve more gas into the liquid, the gas must be placed under additional pressure. With the gas under pressure, more gas can enter the liquid before the process cannot be continued. The higher the pressure involved in forcing the gas into the liquid, the more gas can be dissolved into it.
Carbonation Process
-
The amount of gas that can be dissolved into the liquid before reaching equilibrium is directly proportional to the amount of pressure being employed. By using a purely carbon dioxide gas, the liquid will have significantly more "fizz" than one that uses a mixture of gases. Carbonation is maintained within a bottle or can because the air pressure in the space above the liquid in the container is at least equal to the amount of carbonation in the liquid. This keeps the gas suspended within the liquid until the container is opened. After the container is opened, the air pressure pushing down on the liquid is no longer sufficient to hold in the gas, so the carbon dioxide in the liquid gradually begins escaping. The lower the level of liquid in the container, the more quickly the drink will lose its carbonation. Carbonation is generally done in massive tanks in which the levels of liquid and carbon dioxide gas can be easily controlled. Of course, temperature plays a major role in the carbonation process as well. A liquid with a lower temperature can dissolve more gas before reaching equilibrium than a warmer one, so most drink mediums are kept at a point very near the freezing point while the carbonation process is undertaken.
-
The gas itself is stored separately from the target liquid, and they are separated by a heavy-duty regulator. The regulator controls the speed at which the gas contacts the liquid, and the liquid is stored in climate-controlled tanks that allow it to be kept at a constant temperature while the gas and liquid are mixed. It is extremely important that the regulator and the supply lines are kept in top shape. Because carbon dioxide always moves into areas of lower pressure, any breaks in the line or regulator will allow the gas to escape quickly. Even a massive tank can be bled to a point of such low pressure that it's essentially useless after only a few days of leakage.
eHow Article: How Are Drinks Carbonated?
