Citric acid is an organic acid that is found naturally in plants and animal tissues and fluids. It is a white, crystalline material that is soluble in water. It is a carboxylic acid known by the chemical name beta-hydroxytricarballylic acid. It has a melting point of 307 °F (153 °C), a density of 1.542, and a slightly sour taste.

Citric acid has been known since the 1200's. At this time Vincentius Bellovacensis, an alchemist, identified it as an acid component of lemon and lime juices. In 1784, Carl Wilhelm Scheele was able to isolate this acid component and create crystalline citric acid. Later in 1834, Justus von Liebig found that citric acid is a hydroxy tribasic acid. The basic process for producing citric acid on an industrial scale was developed in 1893. At this time, scientists discovered that citric acid was one of the byproducts fungi growing on a sugar...