Olfactory Quality

The difference between two odors is called olfactory quality, and it is distinct from other aspects of an odor, such as strength. Imagine that two identical cups sit on a kitchen counter, one containing coffee and one containing tea. Though they may look quite similar, a simple sniff of the substance in each cup would enable an easy distinction between the two warm beverages. There is little chance that the rich aroma of coffee would be mistaken for the fresh fragrance of tea. One might be described as slightly “nutty,” or the other as “floral,” but whatever the description, determining that they are different is straightforward.

Historically, attempts have been made to divide odorants according to quality into a few categories, such as fragrant, spicy, or ...