The judges agreed on the following descriptors: “rotten eggs” for hydrogen sulfide, the gas with the strongest correlation to stink; “decomposing vegetables” for methanethiol; and “sweet” for dimethyl sulfide. Though lesser players contribute as well, it is for the most part these three notes, in subtly shifting combinations and percentages, that create the infinite olfactory variety of human flatus. To quote Alan Kligerman, “A gas smell is as characteristic of a person as a fingerprint is.” But harder to dust for.
