What does the term "angel's share" refer to?

The term "angel's share" refers to the portion of whiskey that evaporates during the aging process in the barrel. As whiskey is stored in barrels, a certain amount is lost to the environment due to evaporation through the wood. This loss is often likened to a tribute paid to the "angels," as if they are taking their share of the spirit. This phenomenon of evaporation is influenced by factors such as temperature, humidity, and the size of the barrels. Understanding the angel's share is important because it affects the final yield and concentration of flavors in the whiskey. As whiskey ages, the remaining spirit is often richer and more complex, as it has lost some of its volume but gained flavor from the wood.