Shiraz and Syrah wines are often distinguished by their peppery character. As it turns out, this spicy flavor has a rather pedestrian, chemical nature. According to How to pepper up a bottle of Shiraz by Tim Atkin, “The compound responsible for the peppery aromas and flavours in Syrah/Shiraz has been identified. In case you’re interested, it’s called alpha-ylangene.”
Atkin also comments on the distinction between Shiraz and Syrah:
Syrah and Shiraz are used more or less interchangeably in South Africa – but the more a non-French wine tastes like something from the northern Rhône Valley, the more likely it is to be called Syrah. Conversely, that’s why a handful of producers in the Languedoc-Roussillon are perfectly justified in labelling their vins de pays as Shiraz, despite grumbles from their compatriots. The wines have much more in common with the Barossa Valley than they do with Hermitage or Saint-Joseph.
The only danger I see in this discovery is that unethical wine producers might try and “spice up” a wine chemically rather than letting nature take its course. A little alpha-ylangene, anyone?