What percentage of alcohol loss occurs during the evaporation step of maturation?

During the maturation process of spirits, evaporation plays a significant role in the overall character and profile of the final product. It is commonly accepted that approximately 3% of alcohol loss occurs annually due to evaporation, which is often referred to as the "angel's share." This loss is a result of both atmospheric conditions and the nature of the barrel used for aging, where the alcohol can escape through the porous wood, especially in warmer climates.

Understanding this percentage is crucial for spirits producers as it impacts the final volume and proof of the spirit. The evaporation of alcohol during maturation can lead not only to a decrease in the overall alcoholic strength of the spirit but also contributes to the concentration of flavor compounds, as water tends to evaporate at a different rate than alcohol. This balance affects the complexity and depth of the flavor profile as the spirit interacts with the wood.

Thus, recognizing that the typical alcohol loss during the evaporation step is around 3% enables a better grasp of the maturation process and its effect on spirit quality.