Carbonated water

Lore & Background

The first person thought to aerate water with carbon dioxide was William Brownrigg in the 1740s. Priestley's apparatus, similar to Henry Cavendish's five years earlier, used a bladder to regulate carbon dioxide flow.

Reader's Guide

Carbonated water's significance lies in its role as the precursor to the modern soft drink industry. Carbonated water is made by injecting pressurized carbon dioxide into water, with modern CO₂ sources coming from industrial processes. Its health effects are minimal: it does not appear to affect gastroesophageal reflux disease and may help with constipation after stroke. While slightly more erosive to teeth than non-carbonated water, it is about 1% as corrosive as soft drinks. The acidity (pH 5–6) is neutralized by saliva and does not materially affect a healthy body.

Did You Know?

• Carbonated water has a pH between 5 and 6, similar to apple juice, and is about 1% as corrosive to teeth as soft drinks.
• Modern carbon dioxide used for carbonation comes from industrial processes such as burning fossil fuels or steam reforming of methane.

Origins and the Race to Carbonate

The story of carbonated water begins in the natural world, where artesian wells in Selters in Germany's Taunus mountains, Mihalkovo in Bulgaria's Rhodope Mountains, and Medžitlija in North Macedonia have long yielded naturally effervescent mineral water. The artificial version traces back to the early 1740s, when William Brownrigg is credited as the first to aerate water using carbon dioxide drawn from mines.

The Chemistry of Fizz

When carbon dioxide dissolves in water, it forms a small quantity of carbonic acid, with the acid concentration reaching roughly 0.17 percent of the CO2 present. This reaction gives carbonated water its characteristically tart taste and a pH between 5 and 6—comparable to apple or orange juice but far less acidic than stomach acid. The amount of gas that can dissolve is governed by Henry's law, meaning colder water and higher pressure trap more CO2. This is why manufacturers chill water to just above freezing during carbonation. Once pressure drops or temperature rises, as when a bottle is opened, the gas escapes as visible bubbles. The dissolved CO2 also makes carbonated water slightly denser than plain water, with volume increasing by about 0.8 cubic centimeters per gram of CO2 added. Alkaline salts like sodium bicarbonate or potassium citrate can be introduced to raise the pH and counteract the mild acidity, restoring a more neutral balance to the solution.

Composition and the Art of Manufacturing

Carbonated water exists in many forms, from naturally sourced sparkling mineral water to club soda and commercially produced sparkling variants. The key differentiator lies in mineral content: potassium bicarbonate, sodium bicarbonate, sodium citrate, and potassium sulfate may be present either naturally in mineral springs or added artificially to manufactured products. These salts serve a dual purpose—they replicate the flavor profile consumers associate with natural mineral water and they neutralize the mild acidity introduced by the CO2. Production methods vary widely. Some waters are bottled or canned, others are generated on demand through commercial carbonation systems in bars and restaurants, and still others are made at home using carbon dioxide cartridges. The process relies on pressurizing water with CO2, with the degree of fizz controlled by temperature and pressure. Whether sourced from a well in North Macedonia or a factory in Manchester, the end product delivers that signature effervescent quality.

Health Implications and Dental Considerations

From a health standpoint, plain carbonated water appears to have minimal impact on the human body. A normal, healthy individual maintains acid-base equilibrium through homeostasis, and the CO2 consumed is simply expelled through the lungs. There is no evidence that carbonated water worsens gastroesophageal reflux disease, and tentative research suggests it may ease constipation in stroke patients. The primary concern is dental erosion. Because carbonated water is mildly acidic, it can cause slight wear on tooth enamel. However, saliva partially neutralizes this acidity, and one study found that sparkling mineral water is only about one percent as corrosive to teeth as soft drinks. The pH of carbonated water sits well below that of gastric acid, making it far gentler than the stomach's own environment. In essence, while not entirely inert, carbonated water poses negligible risk to overall health and only a marginal threat to dental integrity compared to sugary sodas.