What component of bourbon influences its final taste after aging?

The final taste of bourbon after aging is significantly influenced by the char level of the barrel. When bourbon is aged in charred oak barrels, the charring process caramelizes the natural sugars in the wood and creates a range of compounds that contribute to the flavor profile. As the bourbon interacts with the charred wood during aging, it extracts various flavors, including vanillin (which imparts vanilla notes), lignin (which can add sweetness), and tannins (which can offer complexity and astringency).

The level of char affects how deeply these flavor compounds are extracted and helps to determine the overall balance of flavors in the bourbon. A heavier char can lead to a richer, more robust flavor profile, while a lighter char may yield a smoother and more subtle character.

While factors such as water quality, fermentation temperature, and duration of bottling can influence the initial components of whiskey prior to aging, the interaction between the spirit and the charred barrel is what most significantly shapes the final flavor after aging.