The Mysterious Rise of Whiskey Fungus in Ireland's Distilling Boom

As Ireland’s whiskey industry flourishes, raking in over €930 million in exports in 2025, an unexpected phenomenon is emerging alongside the beloved spirit: a peculiar black fungus known as Baudoinia. Commonly referred to as 'whiskey fungus' or 'whiskey black,' this fungal growth is increasingly appearing on surfaces near whiskey maturation facilities, raising questions about its impact and health implications.

While whiskey production continues to thrive, with exports to the EU surging by more than 21% over the past four years, the appearance of this fungus prompts curiosity and concern. Baudoinia thrives in the presence of ethanol alcohol, which evaporates during whiskey maturation—often referred to as the 'angels’ share.' This process releases volatile organic compounds (VOCs) into the atmosphere, contributing not only to the fungus's growth but also potentially to ground-level ozone, a harmful pollutant.

Despite the long-standing association between whiskey production and Baudoinia, research into its effects remains limited. A 2022 investigation by the Irish Environmental Protection Agency (EPA) examined complaints of black discoloration on homes near the Midleton distillery in County Cork, confirming the fungus’s presence in distillery environments but not in residential areas. This raises further inquiries about the fungus’s behavior and its potential spread to nearby properties.

Researchers at University College Cork have proposed that ethanol acts as both a germination signal and a carbon source for Baudoinia, indicating its crucial role in the fungus's lifecycle. Factors such as distance from the ethanol source, wind patterns, moisture, and surface texture also influence the extent of fungal colonization.

However, the relationship between whiskey production and environmental health is complex. Though the Scottish government has found no direct evidence linking Baudoinia exposure to health issues, significant gaps in knowledge remain. The EPA is funding a new project in collaboration with Dublin City University and the University of Toronto, aiming to investigate ethanol emissions from maturation facilities and the ecology of Baudoinia in Ireland.

The project will involve emissions estimation, environmental monitoring, and microbiological studies, engaging with communities and the whiskey industry alike. It seeks to balance the growth of Ireland’s whiskey sector with necessary environmental protections, ensuring that communities are not adversely affected by the booming trade.

As we delve deeper into the mysteries of whiskey fungus, it becomes clear that understanding its behavior and potential health effects is essential. The goal is to establish a sustainable path forward for the whiskey industry, preserving both the tradition of whiskey making and the integrity of surrounding environments.

Source: www.independent.co.uk