Which compound contributes to the spicy notes often found in red wines?

The compound that contributes to the spicy notes often found in red wines is phenolics. Phenolic compounds are a diverse group of substances that include tannins, flavonoids, and anthocyanins, which not only affect color and mouthfeel but also play a significant role in the aroma and flavor profile of wine.

In red wines, phenolics are primarily derived from the skins, seeds, and stems of grapes during fermentation, especially during maceration when the juice comes into contact with these components. They can produce a range of sensory experiences, including spiciness, earthiness, and herbal notes. The complexity imparted by phenolics can enhance the wine's overall structure and aging potential, allowing for interesting flavor developments as the wine matures.

Other compounds like sugars mainly contribute sweetness, acids provide freshness and balance, and esters generally influence fruity aromas and flavors, but they do not directly contribute to the spicy character found in many red wines. Thus, phenolics are the key players in delivering those spicy notes that connoisseurs often appreciate in red wine varieties.