At room temperature, citric acid is a white crystalline powder.
Where as the monohydrate forms when citric acid is crystallized from cold water.
The monohydrate can be converted to the anhydrous form by heating above 78 °C.
Citric acid also dissolves in absolute (anhydrous) ethanol (76 parts of citric acid per 100 parts of ethanol) at 15 degrees Celsius.