Basics

• Joseph Priestly discovered carbonated water in the 1770s, when he suspended a bowl of water over a fermenting beer vat. He called this process "impregnating water with fixed air." Sparkling mineral water occurs naturally near volcanic areas, but this is rare. The volcanic gas that escapes from the rocks "impregnates the water with fixed air" in the same manner as the beer vat. You can find natural carbonated water in the Eifel region of Germany, among other places.
  
  

Features

• Carbonated water's distinctive feature is, of course, its carbonation, or the drink's bubbles. Carbonation is the act of dissolving carbon dioxide in the water. A slightly bitter, acidic taste is a feature of most carbonated water because of the carbonic acid (a byproduct of carbonation). Carbonating water involves passing a large amount of pressurized carbon dioxide through water. More pressure allows for more carbon dioxide to dissolve in the water. When you open a bottle of carbonated water, the pressure releases, and the gas tries to escape from the water, making the water bubbly. In the past, this process was accomplished at home by filling a specialized bottle with water and "charging" it with carbon dioxide.
  
  

Types

• Carbonated water comes in a variety of flavors. The most popular flavors are lemon, lime and raspberry. Usually sweetener is not added. Manufacturers also sometimes add a small amount of table salt, sodium citrate, sodium bicarbonate or potassium sulfate to mimic homemade carbonated water's salty taste.
  
  

Misconceptions

• Don't worry about tooth decay when drinking carbonated water. Although drinking sparkling water is slightly harsher on tooth enamel than regular still water, it is still hundreds of times better for your teeth than soda. No hard proof demonstrates that carbonation itself erodes enamel. If you remove the gas from carbonated water (that is, make it "flat"), the tooth erosion levels are still higher than regular mineral water, but it is negligible. Also contrary to popular belief, carbonated drinks do not affect calcium levels in the bones.
  
  

Benefits

• In 2005, the "Journal of Nutrition" published a study in which a group of women were asked to drink 1 liter each day of either still or sparkling mineral water for a month. The following month, the group switched to the other type of water. During each month, the women underwent a series of tests. Surprisingly, during the month the women drank sparkling water, their low density lipoprotein (LDL) cholesterol ("bad" cholesterol) decreased, and their high density lipoprotein (HDL) cholesterol ("good" cholesterol) increased. The exact reason for this is unknown, but the cause might be the sodium present in sparkling mineral water----low-sodium diets could lead to higher cholesterol. Sparkling water also contains bicarbonate, which could reduce the potential negative effects sodium has on blood pressure.