Carbonated water

Carbonated water (also known as soda water, sparkling water, fizzy water, club soda, water with gas, in many places as mineral water, or especially in the United States as seltzer or seltzer water) is water containing dissolved carbon dioxide gas, either artificially injected under pressure or occurring due to natural geological processes. Carbonation causes small bubbles to form, giving the water an effervescent quality. Common forms include sparkling natural mineral water, club soda, and commercially-produced sparkling water.

Club soda and sparkling mineral water and some other sparkling waters contain added or dissolved minerals such as potassium bicarbonate, sodium bicarbonate, sodium citrate, or potassium sulfate. These occur naturally in some mineral waters but are also commonly added artificially to manufactured waters to mimic a natural flavor profile and offset the acidity of introducing carbon dioxide gas. Various carbonated waters are sold in bottles and cans, with some also produced on demand by commercial carbonation systems in bars and restaurants, or made at home using a carbon dioxide cartridge.

It is thought that the first person to aerate water with carbon dioxide was William Brownrigg in 1740. Joseph Priestley invented carbonated water, independently and by accident, in 1767 when he discovered a method of infusing water with carbon dioxide after having suspended a bowl of water above a beer vat at a brewery in Leeds, England. He wrote of the "peculiar satisfaction" he found in drinking it, and in 1772 he published a paper entitled ''Impregnating Water with Fixed Air''. Priestley's apparatus, almost identical to that used by Henry Cavendish five years earlier, which featured a bladder between the generator and the absorption tank to regulate the flow of carbon dioxide, was soon joined by a wide range of others. However, it was not until 1781 that carbonated water began being produced on a large scale with the establishment of companies specialized in producing artificial mineral water. The first factory was built by Thomas Henry of Manchester, England. Henry replaced the bladder in Priestley's system with large bellows.

While Priestley's discovery ultimately led to the creation of the soft drink industry—which began in 1783 when Johann Jacob Schweppe founded Schweppes to sell bottled soda water, he did not benefit financially from his invention. Priestley did however receive scientific recognition when the Council of the Royal Society "were moved to reward its discoverer with the Copley Medal" in 1772.

Composition

Natural and manufactured carbonated waters may contain a small amount of sodium chloride, sodium citrate, sodium bicarbonate, potassium bicarbonate, potassium citrate, potassium sulfate, or disodium phosphate, depending on the product. These occur naturally in mineral waters but are added artificially to commercially produced waters to mimic a natural flavor profile and offset the acidity of introducing carbon dioxide gas (which creates low 5-6 pH carbonic acid solution when dissolved in water).

Artesian wells in such places as Mihalkovo in the Bulgarian Rhodope Mountains, Medžitlija in North Macedonia, and most notably in Selters in the German Taunus mountains, produce naturally effervescent mineral waters.

Health effects

By itself, carbonated water appears to have little impact on health.

Carbonated water such as club soda or sparkling water is defined in US law as a food of minimal nutritional value, even if minerals, vitamins, or artificial sweeteners have been added to it.

Carbonated water does not appear to have an effect on gastroesophageal reflux disease. There is tentative evidence that carbonated water may help with constipation among people who have had a stroke.

Acid erosion

While carbonated water is somewhat acidic, this acidity can be partially neutralized by saliva. A study found that sparkling mineral water is slightly more erosive to teeth than non-carbonated water but is about 1% as corrosive as soft drinks are. A 2017 study by the American Dental Association showed that it would take over 100 years of daily sparkling water consumption to cause damage to human teeth - a claim that could not apply if there is added sugar or artificial flavorings, which often include citric acid and other fruit acids, predicted to have an impact on human teeth.

Chemistry

Carbon dioxide gas dissolved in water at a low concentration (0.2–1.0%) creates carbonic acid (H₂CO₃) according to the following reaction:

: (l) + (g) ⇌ (aq)

The acid gives carbonated water a slightly tart flavor. The pH level between 5 and 6 is approximately in between apple juice and orange juice in acidity, but much less acidic than the acid in the stomach. A normal, healthy human body maintains pH equilibrium via acid–base homeostasis and will not be materially adversely affected by consumption of plain carbonated water. Alkaline salts, such as sodium bicarbonate, potassium bicarbonate, or potassium citrate, will increase pH.

The amount of a gas that can be dissolved in water is described by Henry's Law. In the carbonization process, water is chilled, optimally to just above freezing, to maximize the amount of carbon dioxide that can be dissolved in it. Higher gas pressure and lower temperature cause more gas to dissolve in the liquid. When the temperature is raised or the pressure is reduced (as happens when a container of carbonated water is opened), carbon dioxide effervesces, thereby escaping from the solution.

History

Many alcoholic drinks, such as beer, champagne, cider, and spritzer, were naturally carbonated through the fermentation process for centuries. In 1662 Christopher Merret created 'sparkling wine'. William Brownrigg was apparently the first to produce artificial carbonated water, in the early 1740s, by using carbon dioxide taken from mines. In 1750 the Frenchman Gabriel François Venel also produced artificial carbonated water, though he misunderstood the nature of the gas that caused the carbonation. In 1764, Irish chemist Dr. Macbride infused water with carbon dioxide as part of a series of experiments on fermentation and putrefaction. In 1766 Henry Cavendish devised an aerating apparatus that would inspire Joseph Priestley to carry out his own experiments with regards to carbonated waters. Cavendish was also aware of Brownrigg's observations at this time and published a paper on his own experiments on a nearby source of mineral water at the beginning of January in the next year.

In 1767 Priestley discovered a method of infusing water with carbon dioxide by pouring water back and forth above a beer vat at a local brewery in Leeds, England."The Man Who Discovered Oxygen and Gave the World Soda Water"
New York Times. Retrieved 10 January 2015 The air blanketing the fermenting beer—called 'fixed air'—was known to kill mice suspended in it. Priestley found water thus treated had a pleasant taste, and he offered it to friends as a cool, refreshing drink. In 1772, Priestley published a paper titled ''Impregnating Water with Fixed Air'' in which he describes dripping "oil of vitriol" ( sulfuric acid) onto chalk to produce carbon dioxide gas, and encouraging the gas to dissolve into an agitated bowl of water. Priestley referred to his invention of this treated water as being his "happiest" discovery.

Priestley's apparatus, which was very similar to that invented by Henry Cavendish five years earlier, featured a bladder between the generator and the absorption tank to regulate the flow of carbon dioxide, and was soon joined by a wide range of others, but it was not until 1781 that carbonated water began being produced on a large scale with the establishment of companies specialized in producing artificial mineral water. The first factory was built by Thomas Henry of Manchester, England. Henry replaced the bladder in Priestley's system with large bellows. J. J. Schweppe developed a process to manufacture bottled carbonated mineral water based on the discovery of Priestley, founding the Schweppes Company in Geneva in 1783. Schweppes regarded Priestley as “the father of our industry”. In 1792 he moved to London to develop the business there. In 1799 Augustine Thwaites founded Thwaites' Soda Water in Dublin. A ''London Globe'' article claims that this company was the first to patent and sell "Soda Water" under that name. The article says that in the hot summer of 1777 in London "aerated waters" (that is, carbonated) were selling well but there was as yet no mention of "soda water", though the first effervescent drinks were probably made using " soda powders" containing bicarbonate of soda and tartaric acid. The name soda water arose from the fact that soda ( sodium carbonate or bicarbonate) was often added to adjust the taste and pH.

Modern carbonated water is made by injecting pressurized carbon dioxide into water. The pressure increases the solubility and allows more carbon dioxide to dissolve than would be possible under standard atmospheric pressure. When the bottle is opened, the pressure is released, allowing gas to exit the solution, forming the characteristic bubbles.

Etymology

In the United States, plain carbonated water was generally known either as ''soda water'', due to the sodium salts it contained, or ''seltzer water'', deriving from the German town Selters renowned for its mineral springs.

Sodium salts were added to plain water both as flavoring (to mimic famed mineral waters, such as naturally effervescent '' Selters'', ''Vichy water'' and ''Saratoga water'') and acidity regulators (to offset the acidic 5-6 pH carbonic acid created when carbon dioxide is dissolved in water).

In the 1950s the term club soda began to be popularized.

In the 1970s marketing-driven terms such as ''sparkling water'' gained favor, with an explosion of consumption of the naturally carbonated Perrier water .

Generally, ''seltzer water'' has no added sodium salts, while ''club soda'' still retains some sodium salts.

Products for carbonating water

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. Soda water made in this way tends not to be as carbonated as commercial soda water because water from the refrigerator is not chilled as much as possible, and the pressure of carbon dioxide is limited to that available from the cartridge rather than the high-pressure pumps in a commercial carbonation plant.

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