Seltzer water

Carbonated water (also known as club soda, soda water, sparkling water, seltzer water, "bubbly water" or fizzy water) is water into which carbon dioxide gas under pressure has been dissolved. Some of these have additives, such as sodium chloride, sodium bicarbonate or similar, but seltzer water is almost always composed of water and carbon dioxide with no other additives. This process, known as carbonation, is a process that causes the water to become effervescent. Most carbonated water is sold in ready to drink bottles as mineral water and carbonated beverages such as soft drinks. However, it is rather easy to prepare at home with soda makers.

Whether homemade or store-bought, soda water may be identical to plain carbonated water or it may contain a small amount of table salt, sodium citrate, sodium bicarbonate, potassium bicarbonate, potassium citrate, potassium sulfate, or disodium phosphate, depending on the bottler. These additives are often included to emulate the slightly salty taste soda water developed years ago from first using them as preservatives. Naturally occurring processes also produce effervescent mineral water similar to carbonated water in artesian wells, such as in Mihalkovo in the Bulgarian Rhodope Mountains, in Medžitlija in Macedonia, or most notably in Selters in the German Taunus mountains.

By itself, carbonated water appears to have little impact on health. While carbonated water is somewhat acidic, this acidity is quickly neutralized by saliva.

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Wikipedia