Today’s Wonder of the Day was inspired by Libby from Boomer. Libby Wonders, “Why is soda fizzy?” Thanks for WONDERing with us, Libby !
Have you ever been trapped in the back seat of the family car on a long road trip? Your repeated cries of "Are we there yet?" fall on deaf ears. You read. You stare out the window. You draw pictures. You nap.
Finally, you feel the car begin to slow. You look up and realize that you're pulling into a gas station for a fill-up. Yes! Even though it's just a run-of-the-mill convenience store, it looks like an oasis to your tired eyes.
You're parched from your long journey, and you know there's only one way to quench your thirst. You run inside and search frantically for that colorful dispenser of bubbly beverages: the soda fountain!
You grab a cup and think, "Will 32 ounces be enough?" You press its edge against the ice dispenser. Frozen nuggets of water cascade into your cup and ricochet off its sides. Then you press the cup's edge against the tab underneath the beverage of your choice (root beer!) and watch as a fantastic fountain of frothy refreshment fills your cup all the way to the rim.
As you enjoy your root beer, you begin to WONDER about the soda fountain. How does it work? Could it be magic? Is the root beer you're drinking any different from the kind in the cans and bottles in the store's coolers?
The secret to sodas is the science of carbonation. Flavor and sweeteners are mixed with carbonated water to give sodas their bubbles and that tangy bite that soda drinkers love.
Carbonated water is water that has been supersaturated with carbon dioxide gas. Carbon dioxide and water don't like to mix, so it took quite a while to figure out how to make carbonated water.
Eventually, people figured out that the two keys to making carbonated water were pressure and temperature. If you mix carbon dioxide with very cold water in a pressurized environment, the two will combine to make carbonated water. Johann Jacob Schweppe was one of the first to figure this out way back in 1783 when he invented a hand-cranked carbonator.
Today, modern machines are able to make carbonated water much more quickly and efficiently. When bottles and cans of soda are produced, the ingredients are mixed with carbonated water and then sealed under pressure.
When a can or bottle is opened, the pressure is released, which allows the carbon dioxide to come out of solution in the form of fizzing bubbles. When the carbon dioxide mixes with water, it also forms small amounts of carbonic acid, which gives sodas their unique and tangy bite that fans of soda love.
The soda you get from a fountain is made on-the-fly when you press the dispenser tab. A pressurized carbon dioxide tank and a water pump send pressurized carbon dioxide gas and cold water to a carbonator, where it's mixed and the gas dissolves into the water.
When you press the rim of your cup against a dispenser tab, the carbonator releases carbonated water while, at the same time, a separate pump mixes in flavored syrup to create the drink you want. The latest soda fountains, such as the Coca-Cola Freestyle machine, can mix fruit flavors with soda flavors to create hundreds of possible soda combinations.
The ratio of syrup to carbonated water is carefully controlled by the soda fountain, but these settings can vary from place to place. That's why a soda from a soda fountain may taste slightly different from a bottled or canned soda. Whether you prefer soda from a can, a bottle, or a soda fountain is a matter of personal taste, but there will always be fans of the super-bubbly soda fountain!