Now scientists have identified a highly potent odour molecule that appears to be a trigger for the sense of disgust experienced by many of those with parosmia. The molecule, called 2-furanmethanethiol, found in coffee, was described by those with a normal sense of smell as being coffee- or popcorn-like, but those with parosmia typically described its scent as disgusting, repulsive or dirty.
— Read more in Scientists identify ‘trigger molecule’ for Covid-related changes to smell at The Guardian.