Rotundone: a chemical in wine responsible for pepper aromas

The Australian Wine Research Institute is responsible for some of the best wine research currently being done. One recent, newsworthy project has been the identification of a compound responsible for pepperiness in Australian Shiraz. Called rotundone, it is found in lots of herbs and vegetables, and it’s incredibly potent. For example, just 5 mls of rotundone would be enough to make all wine in Australia taste spicy. Finding it in wine is tricky, though, because of this potency: it’s like trying to identify one person out of six billion. Technically speaking, rotundone is a sesquiterpene.

The aim of this research? It’s to provide Australian winemakers or viticulturalists with the management techniques to be able to moderate spiciness in their wines. However, it’s also of interest that a proportion of people – as many as a fifth – simply can’t smell rotundone. This is one of the most fascinating of all the findings to me. The AWRI researchers state:

Whereas most of the sensory panelists were sensitive to rotundone, approximately
20% could not detect this compound, even in water, at the highest concentration tested (4000 ng/L). Thus, the sensory experience of two consumers enjoying the same glass of Shiraz wine or sharing the same meal seasoned with pepper might be very different. The variation in individual sensitivity to rotundone suggests that the way wines containing this compound are assessed by consumers or wine judges could vary substantially from one person to another. Similarly, the flavor perception of ground pepper might vary considerably among consumers. This is supported by the common practice of pepper being placed on the table or offered to individuals by restaurant waiters

You can access the original research papers here and here.