In the news today I caught glimpse of an interesting article. Australian scientists have been able to identify the compound in red wine that gives it the peppery aroma.  For the last 5 years they have been working on figuring out what gave Shiraz the distinctive black pepper fragrance.  A compound called alpha-ylangene has been discovered to be the culprit; this compound is so strong that, according to the article on TheStar.com, a single drop can turn make an Olympic size pool smell of pepper.

This development means that some day in the future winemakers could alter the pepper aroma in red wine in the same way they now are able to alter it characteristics with different yeast varieties or oak barrel fermentation.