The Practice of Modern Perfumery continues its discussion of the odor wheel. As we’ve seen, the lines between each of the points represent sultry, fresh, exalting, or soothing odor effects, while those points that are in opposition--anti-erogenic versus erogenic, and narcotic versus stimulating--create other odor effects. Anti-erogenic aromas suppress erogenic aromas and stimulating elements such as spices, burnt substances, and gourmand materials balance the tendency of the narcotic to intoxicate and put us to sleep when that’s not what we’re supposed to be doing at all. The opposition of the contrasting points introduces tension in the perfume and gives it power.
Mr. Jellenek discusses animal (erogenic) ingredients such as castoreum, civet, musk, and ambergris; and erogenic compounds of plant origin, namely costus root and ambrette seed. Last, there is the aroma chemical, indole. Indole forms part of the smell of certain flowers—jasmine, orange flowers, and acacia are a few. While indole is considered fecal, and has a distinctly dissonant aroma, these flowers wouldn’t be themselves without it. Other aroma chemicals with fecal nuances are phenylacetic acid and its esters (which also smell like honey), phenyl ethyl alcohol (which smells like roses, but has a gentle funky note), and the paracresols (which smell like creosote and tar; they get animal in a perfume).
Now it gets interesting. While these odors are, according to Jellinek, fecal, there are also so-called sweaty notes. These notes are represented primarily by aldehydes, specifically those having from eight to 12 carbon atoms. He goes on to declare that both sweaty and fecal notes must be included together, with the obvious conclusion that any complex containing indole or any other fecal-like aroma, must also contain an aldehyde. This combination occurs frequently in plants, with various proportions of the two elements coming into play.
Now I’m experimenting with using aldehydes with Black Iris. I tried some C-12 MNA, an often-used aldehyde, and found that it focused the perfume and somehow makes it more perfume-like, more sophisticated. Further experiments ensue.
Coming up, Jellenek’s discussion of some important aroma compounds.