Do tobacco or smoke aromas mean that a wine contains tobacco?

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Dear Dr. Vinny,
Some wines have tobacco aromas. Do those wines contain any tobacco products or extract?
—Valerie, Memphis, Tenn.
Dear Valerie,
While I don’t doubt there are some people experimenting with infusing wine with tobacco, typically no, there are no tobacco products in wine, even if a wine is described as having notes of tobacco, cigar box, smoke or the like.
Some red wines, especially those made from the Nebbiolo, Cabernet Franc and Syrah grapes, can have aromas similar to the aroma of tobacco leaves or cigar boxes. But where do those tobacco aromas come from? The fermentation process can unlock organic compounds in wine that are shared by the fruits and herbs that we often use to describe wine. Tobacco aromas come from a class of compounds called terpenes, which are also responsible for the smell of roses, sage and pine.
Those aromas can also come from aging in new oak barrels. And tobacco notes are also commonly found in aged wines: As fruit flavors fade over time, notes of earth, spice and dried leaves emerge, including tobacco.
I think tobacco aromas are a mostly positive attribute in wine, especially if they’re in balance with the other elements, but I can understand why some people might not like them or find them overwhelming. And if you’re worried about the health risks of tobacco use, there’s nothing to fear when it comes to wines with tobacco aromas: Consuming the terpenes that cause tobacco aromas in wine is not the same as consuming actual tobacco products.
—Dr. Vinny