Geosmin

Geosmin is an organic compound with a distinct earthy flavor and aroma, and is responsible for the earthy taste of beets and a contributor to the strong scent (petrichor) that occurs in the air when rain falls after a dry spell of weather or when soil is disturbed. It is produced by a variety of microorganisms. Chemically, it is an bicyclic alcohol with formula C₁₂H₂₂O, a derviative of decalin. Its name is derived from the Greek γεω "earth" and ὀσμή "smell".