Citric Acid Citric Acid (CA for short, also known as citric acid) is an important organic acid, colorless crystal appearance, odorless, easily soluble in water. According to its different water content, it is divided into monohydrate citric acid and anhydrous citric acid. The calcium salt of citric acid is easily dissolved in cold water than in hot water, this property is commonly used to identify and separate citric acid, and anhydrous citric acid can be obtained by controlling the appropriate temperature when crystallizing, which has many uses in industry, food industry, cosmetic industry, etc.