Carbonated water

Carbonated water is water that contains dissolved carbon dioxide gas. This gas creates small bubbles, which gives the water an effervescent quality. Carbonation can happen through natural geological processes or by human intervention. Natural sparkling mineral waters are found in artesian wells in places like the Bulgarian Rhodope Mountains or the German Taunus mountains. Humans create many other types, such as club soda or commercially produced sparkling water.

The process of carbonation relies on the principles of pressure and temperature. According to Henry's law, the amount of gas that can dissolve in a liquid depends on specific conditions. To maximize carbonation, water is often chilled to just above freezing. Higher gas pressure and lower temperatures both help more carbon dioxide dissolve into the liquid. In modern production, carbon dioxide is injected into the water under high pressure. When a container is opened, the pressure is released. This drop in pressure causes the gas to escape the solution, forming bubbles.

Carbonated waters can be categorized by their mineral content and origin. Natural mineral waters contain minerals that occur naturally in the earth. Commercially produced waters, like club soda, often have minerals added artificially. These include substances like potassium bicarbonate, sodium bicarbonate, sodium citrate, or potassium sulfate. These additives serve two main purposes. They help mimic the flavor profile of natural mineral waters. They also help offset the acidity caused by the carbon dioxide.

The history of carbonated water involves several key scientific figures. William Brownrigg is thought to be the first to aerate water with carbon dioxide in the 1740s. In 1767, Joseph Priestley discovered a method of infusing water by accident. He was at a brewery in Leeds, Yorkshire, when he observed water treated with gas from a beer vat. Priestley called the gas "fixed air." He published a paper on the subject in 1772. His apparatus used a bladder to regulate the flow of gas.

Following Priestley's work, the industry moved toward large-scale production. In 1781, specialized companies began producing artificial mineral water. Thomas Henry built the first factory in Manchester, England. He improved the process by replacing the bladder with large bellows. In 1783, Johann Jacob Schweppe founded the Schweppes company to sell bottled soda water. This event helped launch the modern soft drink industry. While Priestley gained scientific recognition, he did not benefit financially from his invention. Instead, the Royal Society rewarded him with the Copley Medal in 1773.

Chemically, dissolving carbon dioxide in water creates a small amount of carbonic acid. This results in a solution with a pH level between 5 and 6. This acidity is similar to the tartness found in apple juice or orange juice. While this makes the water somewhat acidic, saliva can partially neutralize it. Research shows that sparkling mineral water is slightly more erosive to teeth than plain water. However, it is only about 1% as corrosive as soft drinks. The human body maintains a healthy pH through a process called acid-base homeostasis.

Various tools have been used throughout history to dispense or create carbonated water. The soda siphon, or seltzer bottle, was a common sight in homes and bars during the 20th century. These vessels use gas pressure to drive the water through a spout. In the Victorian era, a device called a gasogene was also used. This device consisted of two linked glass globes. A chemical reaction between tartaric acid and sodium bicarbonate produced the gas. Because these glass globes could explode, they were often surrounded by protective wire mesh.