What is a "foxy" wine?

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Dear Dr. Vinny,
What is a “foxy” wine?
—Rodrigo R., Algarrobo, Chile
Dear Rodrigo,
The term “foxy” refers to a very distinctive note found in some wines, a sort of wild, musky, animal smell that reminds me of the odor of a fur coat. It’s often found in American grape varieties like Concord or Catawba, and it’s usually paired with a pure grapey note.
Because it’s associated with certain grapes and the wines made from them, it’s generally an accepted component ... to a point. Too strong a foxy note can make a wine seem out of balance or disjointed, or it can detract from the rest of the wine’s personality. Scientists have identified the “foxy gene,” which means you might see foxy-free Concord wine in the future.
—Dr. Vinny