You know that wonderful, peppery character shiraz often possesses? It has a source—rotundone (row-TUND-one). The compound was isolated in the mid-2000s by Australian chemists who also discovered that the same molecule gives peppercorns their aroma. Interestingly, while many people can spot the distinctive aroma of rotundone at very low levels, 20% of the participants in the original study failed to detect it at all. That finding is consistent with what is known about many other compounds in wine—namely that individuals vary widely in their ability to detect any given aroma or flavor.