The Angel’s Share: Understanding the Variability Across Different Climates

By Qwen, SEO Specialist, Google

The Angel’s Share and Its Qualitative Differences

The term ldquo;The Angel’s Sharerdquo; refers to the amount of alcohol lost to evaporation during the aging process of spirits in barrels. This phenomenon can vary qualitatively depending on the climate, revealing the complexity of the distilling process.

Climate's Impact on Evaporation

The Angel’s Share is profoundly influenced by climate factors, including air pressure, temperature, and humidity. These elements play a significant role in determining how much water and alcohol evaporate over time. From a distillery warehouse to different locations within it, the process is not uniform.

Water and Alcohol Evaporation

Aqueous molecules in the form of moisture can both enter and exit the barrel. Alcohol, being more volatile, evaporates at a lower temperature than water. Due to the size difference between water and alcohol molecules, the former can more easily permeate the wood of the barrel. This results in a qualitative difference in the Angel’s Share depending on the surrounding climate.

Variability in Alcohol Content

Over many years, spirits typically emerge from the barrel with a reduced alcohol content compared to what was initially placed in it. The extent of this reduction depends on factors such as temperature and humidity. Distilleries can manage their barrels so that the alcohol content increases, a process known as ldquo;over-proofrdquo;—where more water than alcohol evaporates. Lower humidity conditions make this more likely.

Climate-Dependent Aging Process

High temperatures accelerate the aging process of spirits, leading to more evaporation of alcohol. Conversely, high humidity levels decrease water evaporation but also increase some water vapor entry into the barrel. Changes in air pressure and seasonal variations further affect the equilibrium of water and alcohol vapor in and out of the barrels.

Climate Combinations and Distillery Locations

Based on the climates where various distilleries are located, one can expect differing impacts on the Angel’s Share. There are essentially four combinations: warm and dry, warm and humid, cold and dry, and cold and humid. Examining these factors provides insight into how each region affects the aging process.

Thermal Expansion and Contraction

The thermal expansion and contraction of the contents within a barrel during the aging process are also driven by daily and seasonal temperature variations, along with barometric pressure and humidity. These elements can vary significantly within the same rack house, adding another layer of complexity to the aging process.

Further Research and Insights

For those interested in understanding the nuanced impact of climate on The Angel’s Share, a good starting point is the Journal of the Institute of Brewing. With over a century of papers available (many outside the paywall), this publication offers valuable insights into the aging process and the scientific aspects of distilling.

Conclusion

The Angel’s Share is a complex and fascinating process that is deeply influenced by climate. By understanding the various factors at play, distillers and enthusiasts can appreciate the nuances of how spirits evolve over time and with different environmental conditions. Cheers to uncovering the mysteries of aging!