Black pepper is a very characteristic scent that most can easily recognize, as it is used as a seasoning in many dishes and is easy to find.
The scent of pepper is due to a chemical molecule called rotundone. The name was chosen because it was discovered for the first time in the essential oil of Cyperus rotundus (a plant called zigolo weed or "peppercorn"). The same molecule is also present in the essential oils of many other spices: black pepper, marjoram, oregano, rosemary, basil, thyme and geranium.
In both red and white wines, this molecule can be present in high concentrations, even 30-40 times higher than that of the minimum perception threshold of humans' sense of smell. Therefore its contribution to the aromatic bouquet of many wines is undoubted. It has been shown that 99% of rotundone is present in the grape skin and its concentration varies according to the grape variety, the soil and the winemaking technique. For those varieties that always have a high concentration of rotundone, this constitutes a recognized varietal aroma. The most famous example is that of Australian Syrah, a wine that is very popular internationally. But there are plenty of other examples of varieties with strong hints of pepper: The Italian varietals Vespolina e Schioppetino (reds) and the Austrian Grüner Veltli-ner (white).