Para-cresol is an aromatic compound with a strong horse stable-like odor. It contributes to the off-flavor of some foods, but it is also detectable as a characteristic odorant in whiskey and tobacco, as well as in the urine of various mammals. A research team led by the Leibniz Institute of Food Systems Biology at the Technical University of Munich has now discovered which odorant receptor humans use to perceive para-cresol.