Why Does Riesling Smell Like Gasoline?

Riesling is like Rosie the Riveter: it’s got some gentle features, a sweet personality, yet a perfume that smells distinctly like gasoline.

Rosie the Riveter (Photo by NC AFL-CIO)

This gasoline odor comes from a big molecule called TDN (1,1,6-trimethyl-1,2-dihydronaphthalene) which belongs to the norisoprenoid family of aromas.

Norispoprenoids are a class of varietal aroma, meaning they originate in the berry. (Remember, varietal aroma families include terpenes, pyrazines, thiols, and norisoprenoids!)

Here are some common norisoprenoids and their corresponding aromas in wine:

• TDN: petroleum
• ß-Damascenone: sweet and fruity, also an aroma enhancer (think of it like the MSG of wine aromas. A little bit will enhance other smells in the wine!)
• Vitispirane: Floral, fruity, woody (similar to eucalyptus oil)

Norisoprenoids are formed from the breakdown of carotenoids, the yellow-ish color pigments that develop in berries in the vineyard. When it gets really sunny, the grapes need a way to protect themselves from UV light — just like humans. So they build up carotenoids to act as a natural sunscreen!