Brettanomyces bruxellensis
Brettanomyces bruxellensis (the anamorph of Dekkera bruxellensis) is a yeast associated with and named after, the Senne valley near Brussels, Belgium.
| Brettanomyces bruxellensis | |
|---|---|
 | |
| Scientific classification | |
| Kingdom: | |
| Phylum: | |
| Subphylum: | |
| Class: | |
| Order: | |
| Family: | |
| Genus: | |
| Species: | B. bruxellensis |
| Binomial name | |
| Brettanomyces bruxellensis Kufferath and von Laer | |
It is one of several members of the genus Brettanomyces, a genus first isolated in 1889 by Seyffert of the Kalinkin Brewery in St.Petersburg as a "Torula" from English beer which produced the typical "English" taste in lager beer. In 1899 JW Tullo at Guinness described two types of "secondary yeast" in Irish stout.[1] However N. Hjelte Claussen at the Carlsberg brewery was the first to publish a description in 1904, following a 1903 patent (UK patent GB190328184) that was the first patented microorganism in history.[2] The isolation of an organism derived from bottles of traditional English beer was described and therefore the name Brettanomyces was chosen, from "briton" for the British origin and "myces" for the characterisation as fungus.[3] Despite its Latin species name, B. bruxellensis is found all over the globe. In the wild, it is often found on the skins of fruit.
Beer production
B. bruxellensis plays a key role in the production of the typical Belgian beer styles such as Lambic, Flanders red ales, Gueuze, Kriek, and Orval, and is part of spontaneous fermentation biota. It is naturally found in the brewery environment living within oak barrels that are used for the storage of beer during the secondary conditioning stage. Here it completes the long slow fermentation or super-attenuation of beer, often in symbiosis with Pediococcus sp. Macroscopically visible colonies look whitish and show a dome-shaped aspect, depending on the age and size.[4]
B. bruxellensis is increasingly being used by American craft brewers, especially in Maine, California and Colorado. Jolly Pumpkin Artisan Ales, Allagash Brewing Company, Port Brewing Company, Sierra Nevada Brewing Company, Russian River Brewing Company, New Belgium Brewing Company and Rocket Brewing Company have all brewed beers fermented with B. bruxellensis. The beers have a slightly sour, earthy character. Some have described it as having a "barnyard" or "wet horse blanket" flavor.[5]
Wine production
In the wine industry, B. bruxellensis is generally considered a spoilage yeast and it and other members of the genus are often referred to as Brettanomyces ("brett"). Its metabolic products can impart "sweaty saddle leather", "barnyard", "burnt plastic" or "band-aid" aromas to wine. Some winemakers in France, and occasionally elsewhere, consider it a desirable addition to wine, e.g., in Château de Beaucastel, but New World vintners generally consider it a defect. Some authorities consider brett to be responsible for 90% of the spoilage problems in premium red wines.
One defense against brett is to limit potential sources of contamination. It occurs more commonly in some vineyards than others, so producers can avoid purchasing grapes from such sources. Used wine barrels purchased from other vintners are another common source. Some producers sanitize used barrels with ozone. Others steam or soak them for many hours in very hot water, or wash them with either citric acid or peroxycarbonate.
If wine becomes contaminated by brett, some vintners sterile filter it, add SO2, or treat it with dimethyl dicarbonate. Both knowledge and experience are considered helpful in avoiding brett and the problems it can cause.
Biochemistry
B. bruxellensis contains the enzyme vinylphenol reductase.
See also
References
- Gilliland, R. B. (1961). "Brettanomyces. I. Occurrence, Characteristics, and Effects on Beer Flavour". Journal of the Institute of Brewing. 67 (3): 257–261. doi:10.1002/j.2050-0416.1961.tb01791.x.
- Jan Steensels; et al. (2015). "Brettanomyces yeasts — From spoilage organisms to valuable contributors to industrial fermentations". International Journal of Food Microbiology. 206: 24–38. doi:10.1016/j.ijfoodmicro.2015.04.005. PMID 25916511.
- United States Patent Office Application Number: US1904208464A
- Pure Culture Fermentation Characteristics of Brettanomyces Yeast Species and Their Use in the Brewing Industry, Chad Yakobson, 2010
- Rocket Brewing Company on brettanomyces Archived February 1, 2016, at the Wayback Machine
- "Breaking the mold", Wine Spectator,2006 (March 31), 30(16), pp. 99–100 & 103.
- Wild Brews: Beer Beyond the Influence of Brewer's Yeast, Jeff Sparrow, Brewers Publications, Coulder, Colo., 2005