Seltzer

Carbonated water, also known as soda water or sparkling water, is water containing carbon dioxide (CO₂), which bubbles out when the drink is depressurised. When bottled or supplied for final consumption without flavoring, it is also known in the US as club soda in one form or seltzer in another. The latter is commonly sold with a mild fruit flavoring without a sweetener.

Historically, the first soda waters were prepared by adding sodium bicarbonate to lemonade. A chemical reaction between sodium bicarbonate and citric acid occurred to create carbon dioxide.

As with many scientific discoveries, there is confusion about who was first. The person who is usually credited with first successfully creating carbonated water is Joseph Priestley in 1796. However, the Swedish chemistry professor Torbern Bergman had already succeeded in making carbonated water in 1771, mostly to save himself money when he was ill. Both were trying to imitate the naturally-occurring effervescent water that bubbles up from underground springs and was thought to be beneficial to health. It is not known whether Joseph Priestley knew about Torbern Bergman's work, and therefore they can both rightly be called fathers of this invention.

Currently, carbonated water is made by passing pressurized carbon dioxide through water. This increases the solubility, i.e., more CO₂ dissolves than under standard atmospheric pressures. When the pressure is reduced, e.g., by opening the bottle, the gas comes out of the solution, forming the characteristic bubbles.

Carbonated water is believed by some to be good for removing stains, for example coffee stains from mugs, or stains from silver. A frequently used method of preventing red wine stains from setting in is to sprinkle salt on the stain and then apply a liberal amount of carbonated water.

The most popular forms are flavored, and referred to as soft drinks. These are widely sold throughout the world. Major brands include: Coca-Cola, Pepsi, R.C. Cola, and Dr Pepper. Many sales of these beverages are made via vending machines.