Rotundone is a sesquiterpene originally discovered in the tubers of cyperus rotundus
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.
Fruit exposure
Leaf removal time
Crop load
Vine vegetative vigour
Clones
If you enjoy spicy, peppery wines, here are a few examples you should try:
Monsieur Clape's Cornas is systematically considered the best in the appellation, constantly attaining the most amazing levels of excellence. There is always a extremely deep purple, almost black colour that exudes a never ending array of rich complex aromas of dried fruits, liquorice, spice and pepper.
Graillot is making some of the best Syrah in the Rhône Valley. Closes smoky and very long, with excellent clarity and sneaky tannins. The fruit for this wine was sourced from three of the finest vineyards in Cornas: La Cote, Sabarotte and Les Chaillots
Classic Shiraz fruit with strong backbone.
A deep red wine with a nose of fresh plums, wild herbs, and black olives. Its elegant bounty of fruit is supported by fine chocolate notes. Full-bodied, highly concentrated, yet deeply structured with impeccably integrated tanns. A grand wine that flourishes upon decanting.
100% Shiraz; barrel-aged for 18 months in 300-liter hogsheads (approx. 50% new oak, French oak with a small percentage American oak.
This lighter-bodied and elegant indigenous red grape, Pineau d’Aunis is fragrant and has explosive black pepper spice. Pascal Janvier is located in Jasnières in the Loire Valley.
