Home Soda siphons The soda siphon, or seltzer bottle—a glass or metal pressure vessel with a release valve and spout for dispensing pressurized soda water—was a common sight in
bars and in early- to mid-20th-century homes where it became a symbol of middle-class affluence. The gas pressure in a siphon drives soda water up through a tube inside the siphon when a valve lever at the top is depressed. Commercial soda siphons came pre-charged with water and gas and were returned to the retailer for exchange when empty. A deposit scheme ensured they were not otherwise thrown away. Home soda siphons can carbonate flatwater through the use of a small disposable steel bulb containing carbon dioxide. The bulb is pressed into the valve assembly at the top of the siphon, the gas injected, then the bulb withdrawn.
Gasogene The gasogene (or gazogene, or seltzogene) is a late
Victorian device for producing carbonated water. It consists of two linked glass globes: the lower contained water or other drink to be made sparkling, the upper a mixture of
tartaric acid and
sodium bicarbonate that reacts to produce
carbon dioxide. The produced gas pushes the liquid in the lower container up a tube and out of the device. The globes are surrounded by a
wicker or wire protective mesh, as they have a tendency to explode.
Codd-neck bottles In 1872,
soft drink maker Hiram Codd of
Camberwell, London, designed and patented the Codd-neck bottle, designed specifically for
carbonated drinks. The
Codd-neck bottle encloses a
marble and a
rubber washer/gasket in the neck. The bottles were filled upside down, and pressure of the
gas in the bottle forced the marble against the washer, sealing in the carbonation. The bottle was pinched into a special shape to provide a chamber into which the marble was pushed to open the bottle. This prevented the marble from blocking the neck as the drink was poured. Soon after its introduction, the bottle became extremely popular with the soft drink and
brewing industries mainly in the UK and the rest of Europe, Asia, and Australasia, though some
alcohol drinkers disdained the use of the bottle.
R. White's, the biggest soft drinks company in London and south-east England when the bottle was introduced, was among the companies that sold their drinks in Codd's glass bottles. One
etymology of the term
codswallop originates from beer sold in Codd bottles, though this is generally dismissed as a
folk etymology. The bottles were produced for many decades, but gradually declined in usage. Since children smashed the bottles to retrieve the marbles, vintage bottles are relatively rare and have become
collector items, particularly in the UK. Due to the risk of explosion and injuries from fragmented glass pieces, use of this type of bottle is discouraged in most countries, since other methods of sealing pressurized bottles can more easily incorporate release of unsafe pressures. The Codd-neck design is still used for the Japanese soft drink
Ramune, and in the Indian drink called
Banta.
Soda makers Soda makers or soda carbonators are appliances that carbonate water with multiple-use carbon dioxide canisters. A variety of systems are produced by manufacturers and hobbyists. The commercial units may be sold with concentrated syrup for making flavored soft drinks. One major producer of soda carbonators is
SodaStream. Their products were popular during the 1970s and 1980s in the United Kingdom, and are associated with nostalgia for that period and have experienced a comeback in the 2000s.
Commercial The process of dissolving carbon dioxide in water is called
carbonation. Commercial soda water in siphons is made by chilling filtered plain water to or below, optionally adding a
sodium or
potassium based alkaline compound such as
sodium bicarbonate to neutralize the acid created when pressurizing the water with carbon dioxide (which creates high 8-10 pH
carbonic acid-bicarbonate
buffer solution when dissolved in water). The gas dissolves in the water, and a top-off fill of carbon dioxide is added to pressurize the siphon to approximately , some higher than is present in fermenting
champagne bottles. In many modern restaurants and bars soda water is manufactured on-site using devices known as carbonators. Carbonators use mechanical pumps to pump water into a pressurized chamber where it is combined with carbon dioxide from pressurized tanks at approximately . The pressurized carbonated water then flows either directly to taps or mixing heads where flavoring is added before dispensing. ==Uses==