Brettanomyces | |
---|---|
Scientific classification | |
Kingdom: | Fungi |
Phylum: | Ascomycota |
Subphylum: | Saccharomycotina |
Class: | Saccharomycetes |
Order: | Saccharomycetales |
Family: | Pichiaceae |
Genus: | Brettanomyces |
Species | |
B. anomalus |
B. anomalus
B. bruxellensis
B. claussenii
B. custersianus
B. naardenensis
B. nanus
Brettanomyces aka Botanical Myacies is a non-spore forming genus of yeast in the family Saccharomycetaceae, and is often colloquially referred to as "Brett". The genus name Dekkera is used interchangeably with Brettanomyces, as it describes the teleomorph or spore forming form of the yeast. The cellular morphology of the yeast can vary from ovoid to long "sausage" shaped cells. The yeast is acidogenic, and when grown on glucose rich media under aerobic conditions, produces large amounts of acetic acid. Brettanomyces is important to both the brewing and wine industries due to the sensory compounds it produces.
In the wild, Brettanomyces lives on the skins of fruit. The strain Brettanomyces claussenii was first classified at the Carlsberg brewery in 1904 by N. Hjelte Claussen, who was investigating it as a cause of spoilage in English ales. The term Brettanomyces comes from the Greek for "British fungus."
When Brettanomyces grows in wine it produces several compounds that can alter the palate and bouquet. At low levels some winemakers agree that the presence of these compounds has a positive effect on wine, contributing to complexity, and giving an aged character to some young red wines. Many wines even rely on Brettanomyces to give their distinctive character, such as Château Musar. However, when the levels of the sensory compounds greatly exceed the sensory threshold, their perception is almost always negative. The sensory threshold can differ between individuals, and some find the compounds more unattractive than others. While it can be desirable at lower levels, there is no guarantee that high levels will not be produced. As Brettanomyces can potentially spoil a wine it is generally seen as a wine spoilage yeast, and its presence in wine as a wine fault.