Brettanomyces bruxellensis is a yeast that is part of the Ascomycota phylum and plays a key role in the production of several Belgian beers, as well as provides the wine with certain aroma’s.
Brettanomyces bruxellensis is also known as Dekkara bruxellensis, where the name that is used depends on the stage in its life cycle. Brettanamyces bruxellensis is used specifically when we are talking about the non-sexually/asexually reproductive form, whereas Dekkara bruxellensis is used when the spore-forming stage is meant. Asexual reproduction is dominant in the genus, hence Brettanomyces bruxellensis is predominant in nature as well as in daily use. Dekkara bruxellensis, the spore-forming appearance of the fungus, is rarely found in wine, where it is considered a contaminant. More recently, Dekkara bruxellensis has been found to also be a contaminant in bioethanol.
Brettanomyces bruxellensis contamination produces several metabolites when growing, with some of these metabolites being phenolic compounds. They are sometimes referred to as ‘phenolic taint’, and can spoil wine in small concentrations: >140 μg/L for 4-ethylphenol and >600 μg/L for 4-ethylguaiacol.