What role does the "char" on bourbon barrels play?

The char on bourbon barrels plays a crucial role in the flavor profile of the whiskey by caramelizing the natural wood sugars present in the barrel. When barrels are charred, the intense heat converts these sugars into caramel and toasty flavors, which then infuse into the bourbon as it ages. This process contributes rich, complex flavors such as vanilla, caramel, and spice to the spirit, enhancing its overall character and complexity.

The interaction between the charred wood and the whiskey is significant; as the bourbon expands and contracts during temperature fluctuations, it interacts with the charred layer, allowing for extraction of flavors. This is why the char is considered essential in the aging process, influencing not only flavor but also aroma, mouthfeel, and color, making it a key element in the production of bourbon.