What is the primary purpose of evaporation in the maturation of spirits?

The primary purpose of evaporation in the maturation of spirits is to concentrate flavors. During the aging process, especially in wooden barrels, some of the liquid evaporates due to exposure to air and varying temperatures. This evaporation causes a natural reduction in volume, which leads to a higher concentration of flavors in the remaining liquid. Essentially, as the water content decreases, the intensity of the remaining compounds increases, thereby enriching the overall flavor profile of the spirit.

This phenomenon is often referred to as the "angel's share," reflecting the losses incurred during maturation. The interaction of the spirit with the wood of the barrel, along with the condensation of flavors from the evaporation process, contributes significantly to the complexity and depth of the spirit.