What is a defining characteristic of wines that undergo oxidative aging?

Wines that undergo oxidative aging typically develop distinct characteristics due to their exposure to oxygen over time. One key defining characteristic is the increase in acetaldehyde levels, which contributes to a darker color in the wine. During oxidative aging, especially in varieties like Sherry, the oxidation process not only deepens the color but also can lead to the development of richer, more complex flavors, including nutty and caramel notes. This transformation often correlates with higher alcohol levels, as many sherries experience a concentration of flavors that come with the evaporation of water during aging.

Darker colors in oxidative wines result from the formation of pigments during the aging process, alongside the increase in acetaldehyde. These changes are essential for recognizing the impact of oxygen on wine, distinguishing oxidative aging from reductive processes where wines remain lighter and fresher in color.

While the other characteristics listed in the other choices might apply in different contexts, they do not accurately capture the essence of oxidative aging in wines. Understanding the relationship between oxidation, color, and alcohol content helps clarify the unique profile of wines that undergo this aging process.