Which of the following best describes oxidation vs reduction aromas?

• A. Oxidation yields sulfurous aromas; reduction yields nutty aromas
• B. Oxidation yields peppery aromas; reduction yields smoky
• C. Oxidation yields nutty, caramelized, or sherried notes; reduction yields sulfurous, burnt matches, or rotten egg aromas
• D. Both yield the same aromas

Answer: (C)

Oxidation vs reduction aromas come from how oxygen availability shifts the volatile compounds in wine. When wine is exposed to air, oxidative processes build up aldehydes and other oxidation-derived aromas that give nutty, caramelized, or sherried notes (acetaldehyde is a classic example that can contribute almondy or sherry-like character). In contrast, under low-oxygen, reduced conditions, sulfur-containing compounds accumulate, producing sulfurous smells such as rotten egg, burnt matches, or other sulfur notes. This pairing—oxidation with nutty/caramelized/sherried aromas and reduction with sulfurous/burnt-matches/rotten-egg aromas—best describes the typical sensory differences. The other pairings don’t align with how these processes usually manifest in aroma profiles, and the idea that both yield the same aromas ignores the distinct chemistry behind oxidation and reduction.