Fantastic Fungi? Baudoinia compniacensis (whiskey fungus)

By: Joseph D. Cohen

Baudoinia compniacensis (whiskey fungus) is a little-known, recently newsworthy fungus. It’s a crust-like organism that likes humid, warm micro-environments. It grows on a wide variety of substrates, including building walls, road signs, patio furniture, bark, and leaves. It has been found in North America, Europe, Scotland.¹

Its common name — whiskey fungus — comes from the fact that it thrives on ethanol vapor. As a result, B. compniacensis can fruit abundantly near distilleries or whiskey-aging warehouses. Examples: the Hennessy distillery in Cognac, France; Jack Daniels warehouses in Kentucky. But even commercial bakeries can emit enough alcohol vapor to support fruitings.¹

Baudoinia compniacensis is in the news because it’s an issue for residents of places like Lincoln County, Tennessee. Due to nearby Jack Daniels warehouses, the fungus is coating walls, furniture, gardens, trees, and road signs. Locals describe it as “black gunk”. It’s such a problem that residents have sued Jack Daniels for millions, and a judge halted construction of a new Jack Daniels warehouse.^{2 3}

Jack Daniels maintains it’s not a problem, and can be cleaned by power washing.² Local residents disagree. And the mycologist who first described Baudoinia (Professor James A. Scott of the University of Toronto School of Public Health and School of Medicine) says it’s a destructive fungus that can be stopped only by cutting off its ethanol supply:

“The fungus is pretty destructive, and the only way to stop it is to turn off its alcohol supply. It wrecks patio furniture, house siding, almost any outdoor surface. I’ve seen trees choked to death by it. It is a small mercy that it does not also appear to have a negative impact on human health.”²

Some notes on Taxonomy and Ecology

B. compniacensis is an ascomycete — like morels– but is only distantly related to them:

Chart based on Spatafora 2017.⁵

Baudoinia are more primitive than morels, and reproduce asexually via conidaspores. See accompanying drawing, from Richon 1881.⁶ But although they are more primitive, they’re not necessarily older; Baudoinia are part of a later-diverging lineage (Dothideomycetes) than Morchella (Pezizomycetes).

Does anyone or anything enjoy Baudoinia? Maybe snails. The original description of the genus notes that:

“We have observed in numerous, geographically distant localities signs of extensive invertebrate grazing of established colonies of B. compniacensis that suggest scraping by mollusk radulae.” ¹

References

1. James A. Scott, Wendy A. Untereiner, Juliet O. Ewaze, Bess Wong & David Doyle (2007) Baudoinia, a new genus to accommodate Torula compniacensis, Mycologia, 99:4, 592-601, DOI: 10.1080/15572536.2007.11832553
2. Whiskey Fungus Fed by Jack Daniel’s Encrusts a Tennessee Town, New York Times (March 1, 2023); see also Kentuckians Take Distilleries to Court Over Black Gunk, New York Times (Apr.
3. Whiskey fungus infests town — Jack Daniel’s plants targeted in lawsuit, New York Post (March 6, 2023).
4. https://www.dlsph.utoronto.ca/faculty-profile/scott-james-a/
5. Spatafora JW, Aime MC, Grigoriev IV, Martin F, Stajich JE, Blackwell M. 2017. The fungal tree of life: from molecular systematics to genome-scale phylogenies. Microbiol. Spectrum 5(5): FUNK-0053-2016. doi:10.1128/microbiolspec.FUNK-0053-2016.
6. Richon, Revue Mycologique. (Toulouse) Tab. XVII (1881)