What’s the black pepper aroma in wine?
Northern Rhône Syrah and Australian Shiraz are easily identifiable in a blind tasting when they display a distinct freshly cracked black peppercorn aroma. Many syrahs around the world can also have this character. Other grapes with pronounced peppery aromas can include Négrette, Gamay, Pineau d’Aunis, Zinfandel, Petite Syrah and ruby Ports.
But what causes it?
Chemistry can give us the answer. Rotundone was established as the principal aroma impact compound for pepper aroma in wine. Rotundone is a sesquiterpene and is also present in various plants and plant products such as White pepper, Black pepper, Rosemary, Marjoram and Thyme.
How potent is Rotundone?
Pepper aroma can be detected with as little as 8 nano grams per liter in water and 16 ng/L in red wine, however not every taster is going to pick up this spice aroma. Approximately only 20% of tasters can detect this compound even at the highest concentration level (4000 ng/l).
As Rotundone is only present in the skin of the grapes, the analysis is that depending on the climatic and growing conditions, the presence can be higher or lower. It is not detected in the seeds or pulp.
Rotundone increases during late stage of ripening, and can continue to develop after the grapes are fully ripe. Therefore it should not be associated with “green” or “under ripe” fruit aromas like Pyrazines. Rotundone is not necessarily detected on the nose or palate from a freshly picked grape, it is extracted from the skins about 3-4 days into the fermentation process.
In a study done in Duras (AOP Gaillac), Rotundone levels were measured over a period of 4 years. Levels where higher in cooler and wetter vintages. Water plays a role in the levels as in a hot and wet year, there was significant detectable rotundone in the grape skin.
Vine management can also affect rotundone levels.
Leaf removal time
Vine vegetative vigour
If you enjoy spicy, peppery wines, here are a few examples you should try: