Carbon Dioxide

Processing aids

Carbon dioxide is a colorless gas that dissolves in water under pressure and escapes as bubbles when that pressure is released. In drinks it is the source of fizz, sparkle, and effervescence. It can come from fermentation, from naturally gassy springs, or from pressurized injection.

Usage in beverages

Carbonation arises in two broad ways: - **Naturally**, through fermentation. This is the case in bottle-conditioned beer, traditional-method sparkling wine, cider, kvass, traditional ginger beer and root beer, and kombucha. - **Artificially**, by injecting pressurized gas into chilled liquid. This method is used for seltzer and club soda, flavored soft drinks, tonic and ginger mixers, most commercial beer, and many non-alcoholic beers, wines, and sparkling botanical drinks. Carbonation levels vary widely by style, from gently pétillant wines to highly charged colas and mixers.

In depth

Ancient Fermentation and the Unseen Gas

The oldest carbonated drinks were fermented ones, made long before anyone understood why they bubbled. When yeast consumes sugars from grain, fruit, or honey, it gives off carbon dioxide along with alcohol. Beers brewed in Mesopotamia, Egypt, and elsewhere would have carried some natural fizz, especially when drunk young or sealed before fermentation ended. Brewers traditionally let most of the gas vent during fermentation. Lively beer came from finishing fermentation in a closed vessel so that pressure built up inside. That practice survives today in cask- and bottle-conditioned ales, though large commercial breweries now usually add carbonation with pressurized gas instead.[1]

Sparkling Wine in France and England

Classical writers noticed bubbles in wine but could not explain them. In medieval northern France, a light sparkle in still wine was treated as a defect. In southern France, however, monks near Limoux were deliberately bottling wine before fermentation finished by the early 16th century. In 1662 the English scientist Christopher Merret described how adding sugar to finished wine would provoke a second fermentation and make it sparkle. Stronger coal-fired English glass and cork stoppers helped British merchants keep that pressure contained. In Champagne cellars, bursting bottles were a constant hazard, and the fizzy product earned the nickname 'the devil's wine'. Over the 18th and 19th centuries the bubbles shifted from fault to prized feature. Today bottle fermentation, tank fermentation, and simple gas injection all produce sparkling wines worldwide, each at a characteristic pressure.[2]

Mineral Springs and the Invention of Soda Water

Naturally effervescent springs in central Europe and the Balkans had long been valued for their lively, mineral-tinged water. The German town of Selters became so famous that 'seltzer' entered English as a word for fizzy water. In the 1740s the Englishman William Brownrigg appears to have made the first artificial version, using gas drawn from mines. In 1767 Joseph Priestley worked out a practical method after experimenting over fermenting beer at a brewery in Leeds. The heavy 'fixed air' that pooled above the vat dissolved into water held nearby. Priestley enjoyed the result as a cool, pleasant drink and in 1772 published instructions for making the gas from chalk and acid. Within a few years apothecaries and inventors were producing artificial mineral water at scale. They often added sodium salts to imitate famous springs and soften the acidity, which is the origin of the name 'soda water'.[3]

Pharmacies, Soda Fountains, and the Soft Drink

Early artificial mineral waters were sold as medicine, and temperance campaigners promoted them as healthy substitutes for alcohol. Pharmacists soon flavored the water with fruit extracts, herbs, birch bark, dandelion, and sarsaparilla. Flavored carbonated drinks gradually moved out of the dispensary and into everyday life. In Britain, sparkling lemonade and ginger beer were common at refreshment stalls by the 1830s. In the United States, soda fountains spread from the early 19th century and became daily gathering places, serving acid-sharpened 'phosphate' sodas among other drinks. Quinine tonic diluted with sweetened soda became the bitter mixer behind the gin and tonic. Reliable glass bottles and pressure-tight closures arrived in the late 19th century, including marble-stoppered bottles and the crimped metal crown cap. These finally let carbonated drinks travel without going flat, opening the way to the mass-market soft-drink era.[4]

Root Beer and North American Brewed Sodas

In North America, households brewed 'small beers' from roots, barks, and herbs. These included sassafras, sarsaparilla, wintergreen, birch, spruce, and molasses, fermented briefly with yeast. The bubbles came from that short fermentation, which typically left the drink well under 2 percent alcohol. It was strained and bottled for a secondary rise in pressure. Sassafras also contributed a natural foam that became the drink's signature head. As soda water and bottling technology spread in the 19th century, root beer moved from a brewed beverage to a syrup mixed with carbonated water. It gained popularity as a non-alcoholic choice during American Prohibition. Modern versions are almost always force-carbonated, sometimes with added foaming agents to recreate the old texture.[5]

Ginger Beer, Ginger Ale, and the Mixer Tradition

Ginger drinks followed a similar path from fermentation to forced carbonation. Traditional ginger beer, which arose in England, was brewed from ginger, sugar, and lemon with a symbiotic 'ginger beer plant' culture or a homemade 'ginger bug'. The microbes produced both the fizz and a cloudy, pungent character. Ginger ale developed later in Ireland and Canada, first as a darker, sweeter golden style and then as a paler, drier style. Most commercial ginger ale is now made by chilling water to dissolve as much gas as possible, adjusting acidity with alkaline salts, and pressurizing it with carbon dioxide. Both drinks became essential mixers, and ginger ale has long stood in for sparkling wine or beer at alcohol-free occasions.[6]

Kombucha and the Modern Low- and No-Alcohol Revival

Fermented tea, thought to have originated in China, spread through Russia and Eastern Europe in the 19th and early 20th centuries. It reached global popularity in the early 21st century. Kombucha's gentle sparkle comes from yeast in its culture, and many brewers seal the strained tea for a few days of secondary fermentation to build carbonation. Commercial producers must keep alcohol below roughly 0.5 percent, so they balance natural fizz against the risk of continued fermentation, sometimes adding carbon dioxide directly instead. Kvass, water kefir, and revived home sodas belong to the same broad category. So do non-alcoholic beers and dealcoholized sparkling wines, which usually rely on injected gas to restore the bubbles lost in processing. In all of these drinks, carbon dioxide supplies body, brightness, and celebratory feel without the alcohol.[7]

References

  1. [1]EncyclopediaBeer — Wikipedia↑§1
  2. [2]EncyclopediaSparkling wine — Wikipedia↑§2
  3. [3]EncyclopediaCarbonated water — Wikipedia↑§3
  4. [4]EncyclopediaSoft drink — Wikipedia↑§4
  5. [5]EncyclopediaRoot beer — Wikipedia↑§5
  6. [6]EncyclopediaGinger ale — Wikipedia↑§6
  7. [7]EncyclopediaKombucha — Wikipedia↑§7