Citric acid is sometimes referred to as sour salt when being sold as an ingredient for cooking. However, it is most often referred to by its technical name, citric acid.
Citric acid is a naturally occurring substance that gives citrus fruits their sour tang. It is extracted and sold in a white powder form as a food additive to individual consumers for candy making and to large companies, such as soda producers. It is sold under the name citric acid online and in most larger grocery stores. The name "citric acid" is also used on ingredient lists when it is used as a food additive.