A nose for earthy notes: Human odorant receptor for geosmin identified for the first time

Geosmin is a volatile compound of microbial origin with a distinct "earthy" to "musty" odor that can affect the quality of water and food. It is responsible for the typical odor that occurs when rain falls on dry soil. This odorant is produced by microorganisms in the soil and is also found in plants such as cactus flowers and red beet.