This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: Irish whiskey is one of Ireland's great export success stories. Exports were worth more than €930 million in 2025, with the country's much-loved spirit sold all over the world.
Even amid difficult international trading conditions, with concerns about tariffs on exports to the U.S., exports to the EU have grown by more than 21% in four years. However, while thousands of barrels quietly mature in warehouses around Ireland, something else is happening outside some of them. On walls, roofs, road signs, trees and other surfaces close to some whiskey maturation facilities, a distinctive black patina appears.
It may look like soot or air pollution, but in some cases the culprit is a fungus: Baudoinia, commonly known as "whiskey fungus" or "whiskey black," and fueled by the presence of ethanol in the air. Despite the fact that it has been known about for years, there has been surprisingly little research on its effects, such as whether the fungus can spread from distilleries to nearby properties, including residential homes. Ethanol emissions from the industry are also thought to contribute to ground-level ozone, a harmful air pollutant.
But we don't know whether the fungus has any adverse consequences for people's health. It may not be dangerous at all, but this is something we are investigating through a project at Dublin City University. During maturation, ethanol and other volatile compounds evaporate and pass through the porous cask.
They then enter the atmosphere surrounding the distillery. This portion of the whiskey is often known as the "angels' share." A review commissioned by the Scottish government estimated that more than 90% of non-methane volatile organic compound (NMVOC) emissions associated with whiskey production occur during maturation. NMVOCs are chemicals that participate in atmospheric reactions and contribute to the formation of pollutants like ground-level ozone.
Ethanol overwhelmingly dominates these emissions from whiskey production. As they condense in moisture in the air, these ethanol vapors also create an unusual ecological niche. Baudoinia can occur naturally at very low abundance, but exposure to this airborne alcohol can favor its growth.
Extract — continue reading at the source.
