carbonated

Carbonated describes liquids in which carbon dioxide gas has been dissolved under pressure. The term is commonly applied to carbonated water and beverages, collectively known as sparkling or fizzy drinks.

Carbonation occurs when CO2 gas dissolves in a liquid, forming carbonic acid. The gas remains dissolved under sufficient pressure; when the container is opened or the liquid is warmed, CO2 escapes as bubbles. The amount of dissolved CO2 depends on pressure and temperature: colder liquids hold more gas, and higher pressure allows more gas to be dissolved.

Natural carbonation occurs in some mineral waters where CO2 arises from underground geology or fermentation processes. In food and beverage production, carbonation is achieved through direct injection of CO2 or by fermentation in which CO2 is produced by yeast or bacteria. Common carbonated products include carbonated water, soft drinks, beer, and sparkling wines. Seltzer water refers to plain carbonated water; club soda is carbonated water with added minerals such as sodium bicarbonate or potassium sulfate; tonic water contains quinine and sweeteners.

In modern manufacturing, forced carbonation uses pressurized CO2 introduced into the liquid via mixers and piping, often through a diffuser or similar device to generate fine bubbles and even gas distribution. Carbonation also affects flavor perception and mouthfeel, and the acidity from carbonic acid can influence shelf life and texture.

Historical notes indicate that carbon dioxide was first described in the 18th century; English chemist Joseph Priestley demonstrated carbonating water in the 1760s. Swiss-born Jacob Schweppe commercialized bottled carbonated mineral water in the 1780s, laying the groundwork for the modern soda industry.