Biology of the Whiskey Fungus

Abstract

Dark staining on walls, roof tiles, and vegetation in proximity to spirit maturation warehouses was first documented in 1881. French botanists recognized that the main agent responsible was a fungus and named it Torula compniacensis. Hiding in plain sight, the fungus then remained mostly forgotten by science for well over a century. Using modern methods, the genus Baudoinia was described to accommodate the fungus, and a series of in vitro and in vivo investigations were conducted to study its physiology and ecology. What emerged is an intricate and fascinating story of a fungus whose prosperity is tied to human vice and a powerful industry in fear of the implications. We review the literature on warehouse staining and specifically the whiskey fungus, tracing the history of its discovery and rediscovery, summarizing its taxonomy and nomenclature, and synthesizing the modern literature on its physiology, genetics, and ecology. Major knowledge gaps are identified and a framework for future studies is outlined.