Carbonated beverages and ice cream products often require their own storage in a busy restaurant. Because both must be refrigerated, we include them in this chapter. Carbonated beverages are created on the spot at most restaurants by mixing syrup and carbonated water and propelling it through a system of chilled tubes (called lines) to the dispenser. There are two types of carbonated drink machines, postmix and premix; and two types of dispensers, fountain and cobra gun.
The post-mix system begins with the syrup concentrate moving through the chill line and the carbonated water moving through another line to join the dispensing head, where the freshly mixed soda is poured into a cup or glass. A valve for each drink can be electric or manual. Syrup is purchased in three- or five-gallon tanks or cases that sit under the dispenser. Valves on the syrup containers allow for easy connection to the system. Most systems use carbon dioxide as the gas that drives liquids through the lines.
The pre-mix system works much the same as the post-mix system, except that the syrup and carbonated water are purchased already mixed and are propelled up a single line to the dispensing head. Both pre-mix and post-mix dispensers typically contain space for ice storage and chutes for dispensing ice into cups. Self-contained fountain units come in large freestanding sizes with a dozen valves or more, and countertop sizes as small as three feet wide. They can be purchased from the same company that supplies the syrup. There are advantages and disadvantages to each type of beverage system. Postmix syrup concentrate is less expensive than the premix product, but postmix requires more lines and is more complicated to maintain and connect.
In large operations where more than one dispensing site is needed (for example, in a cafeteria), you can set up a central propulsion and cooling system and connect it to more than one row of dispensing valves. In a bar, the dispensing unit is likely to be used only by the bartenders. It is called a gun (bar gun, cobra gun, gun and/or quick gun) and is connected to a multi-line hose called a cobra. The top of the dispensing head features up to eight buttons that you can press, each linked to a different line.
The cobra gun can dispense up to seven soft drinks and water from a single head. Soda dispensers cool beverages in two ways. One is a small electric refrigeration system that runs on a 1/4 or 1/2 horsepower compressor and can chill up to 700 12-ounce drinks per hour. The other option is a cold plate, which is a sheet of metal cooled by direct contact with ice in a container. All beverage lines go through the metal plate, cooling the syrup and water. The larger the plate and the more its surface is covered with ice, the colder the final product will be. The temperature of your beverage dispenser is critical, because carbonation tends to bubble above 40 degrees Fahrenheit, resulting in flat drinks.
