angel’s share is an evocative expression (from the French, la part des anges) for the volume of alcohol that evaporates from spirits aging in barrels. It is usually expressed in percent per year. Generally, spirits stored in wooden barrels (usually oak), through indirect contact with the air, decrease in alcoholic strength and volume.
The angel’s share varies in quantity and quality depending on the temperature and humidity. In a more humid cellar, the angel’s share will contain more alcohol, thus favoring the progressive drop in proof of the spirit in the barrel. A drier cellar will cause relatively more water to evaporate through the wood, resulting in a slightly “spicier,” and of course stronger, spirit.
The angel’s share varies in quantity depending on the climate. For instance, each year in Cognac, the “angels” consume about 2.5 percent of the total stock, the equivalent of thirty million bottles. In the Caribbean, the angel’s share is 7 percent per year on average and can sometimes be as high as 10 percent per year.
To compensate for evaporation, the casks are sometimes topped up regularly with fresh spirit. This technique is sometimes referred as the solera system.
A fungus, Torula compniacensis, feeds on alcohol vapors. On the roofs and walls of the cellars, a light black veil signals its presence.
Ray, Cyril. Cognac. New York: Stein & Day, 1974.
By: Alexandre Gabriel