For the true perfume fanatic, Luca Turin needs no introduction. The first edition of his Parfums: Le Guide was published in 1992, and quickly brought him to the attention of perfume fans and perfumers alike. It became the bestselling perfume guide in France, and for many of us, it remains the gold standard of intelligent writing about perfume.

His theory of smell first gained widespread notice through the BBC documentary The Code in the Nose, and was later the subject of Chandler Burr's 2002 book The Emperor of Scent. If you are not familiar with his theory, you can read a very brief background on shape vs. vibration in this article on Olfaction. There is a longer article on current theories of olfaction on the Leffingwell site.

Since 2001, Dr. Turin has been with Flexitral, Inc.

The Emperor of Scent leaves off in 1999. Have your theories about how smell works changed since then, and if so, how?
The state of the art has moved on, though the main points remain unchanged. All is detailed in my article "Rational Odorant Design" which can be downloaded from the Flexitral website. A lot of progress has also been made on the practical (odor prediction) side, particularly in connection with predicting odorant intensity.

Can you comment on the experiments done last year by Vosshall & Keller at Rockefeller University that failed to find any evidence for vibration theory?
Their article is a valuable scientific contribution to the continuing debate as to whether we smell shape or vibration. Their basic conclusion is that untrained subjects cannot tell a particular pair of isotopes apart when smelling them at a particular concentration. This leaves open the question of whether trained observers, different concentrations and other isotopes would have given a different answer, and has to be seen in context of other similar work on animals and humans which reached a different conclusion.

Can you tell us a little about the work you are now doing at Flexitral?
Flexitral uses my methods to create novel perfume and flavor molecules. We reach the desired target two orders of magnitude faster (and more cheaply) than the competition. We have focused on replacements for the molecules restricted in use by the European Union because of their allergen properties, but we also create novel materials.

Many of us would love to know if you have any plans to update Parfums: Le Guide?
I thank all the aficionados for reminding me periodically that this is something I must do one day. It needs time which my research work hasn't allowed me yet.

And are there any perfumes that have been released since the last version of your guide was published that you particularly admire?
Bulgari Black, Osmanthus by the Different Company, Beyond Paradise, Histoire d'Eau (topaze) by Mauboussin, and Shalimar Lite.

If you could bring back any discontinued perfumes, which would you choose?
Fath Iris Gris, Lucien Lelong Elle, Elle, Coty l'Origan, Shiseido Nombre Noir

Sincere thanks to Luca Turin for participating in this interview, which was conducted by email. More reading: Chandler Burr's website includes some of Turin's perfume reviews and other material that was not included in the Emperor of Scent. You can also listen to a 2003 NPR interview with Chandler Burr, and there are also links to a number of articles about smell on the Flexitral website.