Brettanomyces
Encyclopedia
Brettanomyces 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 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 discovered 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."
s 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 in Château Musar
and Château de Beaucastel
. 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
.
Wines that have been contaminated with Brettanomyces taints are often referred to as "Bretty," "metallic," or as having "Brett character." Brettanomyces taint in wine is also sometimes incorrectly identified as cork taint
.http://www.spittoon.biz/cork_taint_and_brettanomyces.html
These compounds can impart completely different sensory properties to a wine when they are present in different ratios.
and Sauvignon Blanc
. In some cases the yeast has caused contamination in sparkling wine
s produced by the Méthode champenoise when en tirage. It is thought Brettanomyces can be introduced to a winery by insect vectors such as fruit flies
, or by purchasing Brett contaminated wine barrels. The ability to metabolise the disaccharide
cellobiose
, along with the irregular surface of a barrel interior, provide ideal conditions for Brettanomyces growth. Once the yeast is in a winery it is hard to eradicate and is spread readily by unsanitised equipment.
, to which the yeast is particularly sensitive. The addition of other sterilising compounds such as dimethyl dicarbonate
often has a similar effect. Alternatively the wine can be bottled after sterile filtration, which physically removes the yeast. Wines that are vinified to low residual sugar levels, such as <1.0g/L, are also less likely to be spoiled as the main growth substrate
has been limited. However growth has been reported at levels below this and it is assumed that the yeast can use other substrates.
styles Brettanomyces is viewed as a contaminant and the characteristics it imparts are considered unwelcome "off-flavours." However, in some styles, particularly certain traditional Belgian ales, it is appreciated and encouraged. Lambic
and gueuze
owe their unique flavour profiles to Brettanomyces, and it is also found in Oud Bruin
and Flanders red ale
. Commercial examples of these styles include Liefmans Brown Ale, Rodenbach
Grand Cru, and Duchesse de Bourgogne
. The Orval
Trappist monastery is unique in crafting the only Trappist beer
with Brettanomyces characteristics. In Orval's case, the brewers add the yeast to the beer at bottling.
Several American craft breweries use Brettanomyces in their beers. This use began with a renewed interest in Belgian style ales and later formed new styles altogether (Brewers Association, 2007 Great American Beer Festival Style Guidelines, section 13a, 16). Some breweries use 100% Brettanomyces for the fermentation of some of their beers, and omit Saccharomyces
from the recipe. It is common for American brewers that use Brettanomyces to also include lactic acid producing bacteria such as Lactobacillus
, and Pediococcus
in order to provide sourness to the beer.
While Brett is sometimes pitched into the fermenter, aging in wood barrels previously infected with Brettanomyces is another method used to impart the complexity and sourness contributed by these strains of yeast. A prime example of this is Captain Lawrence Brewing Company
's Rosso e Marrone, an award winning Oud Bruin
aged in wine barrels harboring these yeasts.
Examples of American breweries that use Brettanomyces in their beer include Ithaca Beer Company (in their Brute), Russian River Brewing Company
, Deschutes Brewery
, Lost Abbey
, Captain Lawrence Brewing Company
, New Belgium Brewing Company
, Goose Island Beer Company (in their Matilda), Boulevard Brewing Company
(in their Saison-Brett), Allagash Brewing Company
, Brewery Ommegang
(in their Ommegeddon and Bière de Mars), Jolly Pumpkin Artisan Ales
, Victory Brewing Company
(in Wild Devil), Saint Somewhere Brewing, Surly Brewing Company
(in their Pentagram and Five), and Avery Brewing Company (in Depuceleuse).
While most stout
s achieve their sour tang through the use of acidulated malt, roasted barley, or — in the case of "milk stouts" — lactose
and incipient lactic acid, some use Brettanomyces for the same purpose. Prior to 1980s-era changes in its fermentation regimen, Guinness
's Foreign Extra Stout is held to have been one such.
Spore
In biology, a spore is a reproductive structure that is adapted for dispersal and surviving for extended periods of time in unfavorable conditions. Spores form part of the life cycles of many bacteria, plants, algae, fungi and some protozoa. According to scientist Dr...
genus of yeast
Yeast
Yeasts are eukaryotic micro-organisms classified in the kingdom Fungi, with 1,500 species currently described estimated to be only 1% of all fungal species. Most reproduce asexually by mitosis, and many do so by an asymmetric division process called budding...
in the family Saccharomycetaceae
Saccharomycetaceae
The Saccharomycetaceae are a family of yeast in the order Saccharomycetales that reproduce by budding. Species in the family have a cosmopolitan distribution distribution, and are present in a wide variety of habitats, especially those with a plentiful supply of carbohydrate sources...
, 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
Spore
In biology, a spore is a reproductive structure that is adapted for dispersal and surviving for extended periods of time in unfavorable conditions. Spores form part of the life cycles of many bacteria, plants, algae, fungi and some protozoa. According to scientist Dr...
form of the yeast. The cellular morphology
Morphology (biology)
In biology, morphology is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features....
of the yeast can vary from ovoid to long "sausage" shaped cells. The yeast is acidogenic, and when grown on glucose rich media produces large amounts of acetic acid
Acetic acid
Acetic acid is an organic compound with the chemical formula CH3CO2H . It is a colourless liquid that when undiluted is also called glacial acetic acid. Acetic acid is the main component of vinegar , and has a distinctive sour taste and pungent smell...
. Brettanomyces is important to both the brewing
Brewing
Brewing is the production of beer through steeping a starch source in water and then fermenting with yeast. Brewing has taken place since around the 6th millennium BCE, and archeological evidence suggests that this technique was used in ancient Egypt...
and wine
Wine
Wine is an alcoholic beverage, made of fermented fruit juice, usually from grapes. The natural chemical balance of grapes lets them ferment without the addition of sugars, acids, enzymes, or other nutrients. Grape wine is produced by fermenting crushed grapes using various types of yeast. Yeast...
industries due to the sensory compounds it produces.
In the wild, Brettanomyces lives on the skins of fruit. The strain Brettanomyces claussenii was discovered 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."
Wine
When Brettanomyces grows in wine it produces several compounds that can alter the palate and bouquet. At low levels some winemakerWinemaker
A winemaker or vintner is a person engaged in winemaking. They are generally employed by wineries or wine companies, where their work includes:*Cooperating with viticulturists...
s 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 in Château Musar
Chateau Musar
Château Musar is the name of a Lebanese winery in Ghazir, Lebanon, 15 miles north of the capital Beirut. Musar grapes grow in the Beqaa Valley, a fertile sunny valley at an altitude of ca. , situated 25 miles east of Beirut.-History:...
and Château de Beaucastel
Château de Beaucastel
Château de Beaucastel is a winery located in the southern part of the Rhône valley in France, which is primarily noted for its Châteauneuf du Pape wines produced in a long-lived style. For its red Châteauneuf du Pape, Beaucastel includes all 13 grape varieties that are traditionally part of the...
. However when the levels of the sensory compounds greatly exceed the sensory threshold
Sensory threshold
Sensory threshold is a theoretical concept used in psychophysics. A stimulus that is less intense than the sensory threshold will not elicit any sensation...
, 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
Wine fault
A wine fault or defect is an unpleasant characteristic of a wine often resulting from poor winemaking practices or storage conditions, and leading to wine spoilage. Many of the compounds that cause wine faults are already naturally present in wine but at insufficient concentrations to adversely...
.
Wines that have been contaminated with Brettanomyces taints are often referred to as "Bretty," "metallic," or as having "Brett character." Brettanomyces taint in wine is also sometimes incorrectly identified as cork taint
Cork taint
Cork taint is a broad term referring to a wine fault characterized by a set of undesirable smells or tastes found in a bottle of wine, especially spoilage that can only be detected after bottling, aging and opening...
.http://www.spittoon.biz/cork_taint_and_brettanomyces.html
Sensory compounds
The compounds responsible contributing certain sensory characters to wine are;- 4-ethylphenol4-Ethylphenol4-Ethylphenol, often abbreviated to 4-EP, is a phenolic compound with the molecular formula C8H10O. In wine and beer it is produced by the spoilage yeast Brettanomyces. When it reaches concentrations greater than the sensory threshold it can give the wine aromas described as barnyard, medicinal,...
: Band-aids, barnyard, horse stable, antiseptic - 4-ethylguaiacol: Bacon, spice, cloves, smoky
- isovaleric acid3-Methylbutanoic acid3-Methylbutanoic acid, or more commonly isovaleric acid, is a natural fatty acid found in a wide variety of plants and essential oils. Isovaleric acid is clear colorless liquid that is sparingly soluble in water, but extremely soluble in most common organic solvents.Isovaleric acid has a strong...
: Sweaty saddle, cheese, rancidity
These compounds can impart completely different sensory properties to a wine when they are present in different ratios.
Origins in the winery
Brettanomyces is most associated with barrel aged red wines, but has also been found in ChardonnayChardonnay
Chardonnay is a green-skinned grape variety used to make white wine. It is originated from the Burgundy wine region of eastern France but is now grown wherever wine is produced, from England to New Zealand...
and Sauvignon Blanc
Sauvignon blanc
Sauvignon Blanc is a green-skinned grape variety which originates from the Bordeaux region of France. The grape most likely gets its name from the French word sauvage and blanc due to its early origins as an indigenous grape in South West France., a possible descendant of savagnin...
. In some cases the yeast has caused contamination in sparkling wine
Sparkling wine
Sparkling wine is a wine with significant levels of carbon dioxide in it making it fizzy. The carbon dioxide may result from natural fermentation, either in a bottle, as with the méthode champenoise, in a large tank designed to withstand the pressures involved , or as a result of carbon dioxide...
s produced by the Méthode champenoise when en tirage. It is thought Brettanomyces can be introduced to a winery by insect vectors such as fruit flies
Drosophila melanogaster
Drosophila melanogaster is a species of Diptera, or the order of flies, in the family Drosophilidae. The species is known generally as the common fruit fly or vinegar fly. Starting from Charles W...
, or by purchasing Brett contaminated wine barrels. The ability to metabolise the disaccharide
Disaccharide
A disaccharide or biose is the carbohydrate formed when two monosaccharides undergo a condensation reaction which involves the elimination of a small molecule, such as water, from the functional groups only. Like monosaccharides, disaccharides form an aqueous solution when dissolved in water...
cellobiose
Cellobiose
Cellobiose is a disaccharide with the formula [HOCH2CHO3]2O. Cellobiose consists of two glucose molecules linked by a β bond. It can be hydrolyzed to glucose enzymatically or with acid. Cellobiose has eight free alcohol groups, one acetal linkage and one hemiacetal linkages, which give rise to...
, along with the irregular surface of a barrel interior, provide ideal conditions for Brettanomyces growth. Once the yeast is in a winery it is hard to eradicate and is spread readily by unsanitised equipment.
Control measures
The growth of Brettanomyces is best controlled by the addition of sulfur dioxideSulfur dioxide
Sulfur dioxide is the chemical compound with the formula . It is released by volcanoes and in various industrial processes. Since coal and petroleum often contain sulfur compounds, their combustion generates sulfur dioxide unless the sulfur compounds are removed before burning the fuel...
, to which the yeast is particularly sensitive. The addition of other sterilising compounds such as dimethyl dicarbonate
Dimethyl dicarbonate
Dimethyl dicarbonate or DMDC is a colourless liquid with a sharp odour. Its primary use is as a beverage preservative and or processing aid or sterilant , and acts by inhibiting the enzymes acetate kinase and L-glutamic acid decarboxylase...
often has a similar effect. Alternatively the wine can be bottled after sterile filtration, which physically removes the yeast. Wines that are vinified to low residual sugar levels, such as <1.0g/L, are also less likely to be spoiled as the main growth substrate
Substrate (biology)
In biology a substrate is the surface a plant or animal lives upon and grows on. A substrate can include biotic or abiotic materials and animals. For example, encrusting algae that lives on a rock can be substrate for another animal that lives on top of the algae. See also substrate .-External...
has been limited. However growth has been reported at levels below this and it is assumed that the yeast can use other substrates.
Beer
In most beerBeer
Beer is the world's most widely consumed andprobably oldest alcoholic beverage; it is the third most popular drink overall, after water and tea. It is produced by the brewing and fermentation of sugars, mainly derived from malted cereal grains, most commonly malted barley and malted wheat...
styles Brettanomyces is viewed as a contaminant and the characteristics it imparts are considered unwelcome "off-flavours." However, in some styles, particularly certain traditional Belgian ales, it is appreciated and encouraged. Lambic
Lambic
Lambic is a very distinctive type of beer brewed only in the Pajottenland region of Belgium and in Brussels itself at the Cantillon Brewery and museum...
and gueuze
Gueuze
Gueuze is a type of lambic, a Belgian beer. It is made by blending young and old lambics into a new beer, which is then bottled for a second fermentation. Because the young lambic is not fully fermented, it contains fermentable sugars, which allow the second fermentation to occur...
owe their unique flavour profiles to Brettanomyces, and it is also found in Oud Bruin
Oud bruin
Oud Bruin, also known as Flanders Brown, is a style of beer originating from the Flemish region of Belgium. The name literally translates as "old brown", referring to the long aging process which can take up to a year. It undergoes a secondary fermentation, which takes several weeks to a month,...
and Flanders red ale
Flanders red ale
Flanders red ale is a style of sour ale usually brewed in Belgium. Although sharing a common ancestor with English porters of the 17th century, the Flanders red ale has evolved along a different track: the beer is often fermented with organisms other than Saccharomyces cerevisiae, especially...
. Commercial examples of these styles include Liefmans Brown Ale, Rodenbach
Rodenbach
Rodenbach was a brewery and a brewing family from Roeselare, Belgium. The brewery is now owned by Palm Breweries. It is noted for its production of barrel-aged sour beers in the Flemish tradition.-Brewery:...
Grand Cru, and Duchesse de Bourgogne
Duchesse de Bourgogne (beer)
Duchesse de Bourgogne is a Flanders red ale-style beer produced by Brouwerij Verhaeghe in Vichte, Belgium. After a primary and secondary fermentation, this ale is matured in oak barrels for 18 months. The final product is a blend of a younger 8-month-old beer with an 18-month-old beer...
. The Orval
Orval Brewery
Orval Brewery is a Belgian trappist brewery located within the walls of the Abbaye Notre-Dame d'Orval in the Gaume region of Belgium.The brewery produces two beers, which are marketed as trappist beer, Orval and Petite Orval.- History :...
Trappist monastery is unique in crafting the only Trappist beer
Trappist beer
A Trappist beer is a beer brewed by or under control of Trappist monks. There are a total of 174 Trappist monasteries worldwide ; only seven produce Trappist beer and are authorized to label their beers with the Authentic Trappist Product logo that indicates a compliance to the various rules of...
with Brettanomyces characteristics. In Orval's case, the brewers add the yeast to the beer at bottling.
Several American craft breweries use Brettanomyces in their beers. This use began with a renewed interest in Belgian style ales and later formed new styles altogether (Brewers Association, 2007 Great American Beer Festival Style Guidelines, section 13a, 16). Some breweries use 100% Brettanomyces for the fermentation of some of their beers, and omit Saccharomyces
Saccharomyces
Saccharomyces is a genus in the kingdom of fungi that includes many species of yeast. Saccharomyces is from Greek σάκχαρ and μύκης and means sugar fungus. Many members of this genus are considered very important in food production. One example is Saccharomyces cerevisiae, which is used in making...
from the recipe. It is common for American brewers that use Brettanomyces to also include lactic acid producing bacteria such as Lactobacillus
Lactobacillus
Lactobacillus is a genus of Gram-positive facultative anaerobic or microaerophilic rod-shaped bacteria. They are a major part of the lactic acid bacteria group, named as such because most of its members convert lactose and other sugars to lactic acid. They are common and usually benign...
, and Pediococcus
Pediococcus
Pediococcus is a genus of Gram-positive lactic acid bacteria, placed within the family of Lactobacillaceae. They usually occur in pairs or tetrads, and divide along two planes of symmetry, as do the other lactic acid cocci genera Aerococcus and Tetragenococcus. They are purely homofermentative...
in order to provide sourness to the beer.
While Brett is sometimes pitched into the fermenter, aging in wood barrels previously infected with Brettanomyces is another method used to impart the complexity and sourness contributed by these strains of yeast. A prime example of this is Captain Lawrence Brewing Company
Captain Lawrence Brewing Company
-General:Captain Lawrence Brewing Company is an award-winning craft brewery located in Pleasantville, NY. The brewery is owned and run by head brewer Scott Vaccaro. Vaccaro, a homebrewer since 1995, trained in brewing science at UC Davis. He interned at Adnams Brewery, in the U.K...
's Rosso e Marrone, an award winning Oud Bruin
Oud bruin
Oud Bruin, also known as Flanders Brown, is a style of beer originating from the Flemish region of Belgium. The name literally translates as "old brown", referring to the long aging process which can take up to a year. It undergoes a secondary fermentation, which takes several weeks to a month,...
aged in wine barrels harboring these yeasts.
Examples of American breweries that use Brettanomyces in their beer include Ithaca Beer Company (in their Brute), Russian River Brewing Company
Russian River Brewing Company
Russian River Brewing Company is a brewery and brewpub located in downtown Santa Rosa, California.-History:Russian River Brewing Company was created in 1997 when Korbel Champagne Cellars of Guerneville, California decided to try their hand at brewing beer. Brewer Vinnie Cilurzo was hired as...
, Deschutes Brewery
Deschutes Brewery
Deschutes is a craft brewery founded in 1988 in Bend, Oregon, USA. The company produces a range of beers which it currently distributes to eighteen states...
, Lost Abbey
Pizza Port
Pizza Port Brewing Company is a brewpub with four locations in California . A new location in Ocean Beach, California opened in May of 2010...
, Captain Lawrence Brewing Company
Captain Lawrence Brewing Company
-General:Captain Lawrence Brewing Company is an award-winning craft brewery located in Pleasantville, NY. The brewery is owned and run by head brewer Scott Vaccaro. Vaccaro, a homebrewer since 1995, trained in brewing science at UC Davis. He interned at Adnams Brewery, in the U.K...
, New Belgium Brewing Company
New Belgium Brewing Company
New Belgium Brewing Company is a regional brewery located in Fort Collins, Colorado. It opened in 1991 after Jeff Lebesch, the brewery's founder, took his home-brewing passion commercial. In 2009, it produced over 582,000 barrels of its various labels...
, Goose Island Beer Company (in their Matilda), Boulevard Brewing Company
Boulevard Brewing Company
Boulevard Brewing Company is an independent regional craft brewery located in Kansas City, Missouri. The Brewers Association currently ranks Boulevard as the 10th largest craft brewery, and the 17th largest active brewery in the United States. The sale of Anheuser-Busch to InBev made Boulevard the...
(in their Saison-Brett), Allagash Brewing Company
Allagash Brewing Company
Allagash Brewing Company is an American brewery located in Portland, Maine.Founded in 1994 by Rob Tod, Allagash sold its first batch of beer in the summer of 1995. Tod had been working in breweries around the U.S. and recognized a void in the craft brewing movement...
, Brewery Ommegang
Brewery Ommegang
Brewery Ommegang is a Belgian brewery located near Cooperstown, New York that specializes in Belgian-style ales.-History:Ommegang began brewing Belgian-style ales in 1997...
(in their Ommegeddon and Bière de Mars), Jolly Pumpkin Artisan Ales
Jolly Pumpkin Artisan Ales
Jolly Pumpkin Artisan Ales is a microbrewery in Dexter, Michigan founded by Ron Jeffries in 2004. It operates two pubs in Ann Arbor and Traverse City, Michigan. Jolly Pumpkin produces a variety of unfiltered and unpasteurized "rustic country beers"....
, Victory Brewing Company
Victory Brewing Company
Victory Brewing Company is a brewery founded in 1996 in Downingtown, Pennsylvania, USA. The main brands are HopDevil, Prima Pils, Headwaters Pale Ale, Golden Monkey and Storm King, which are distributed in 30 states. Victory Brewing is located at 420 Acorn Lane Downingtown, Pennsylvania 19335...
(in Wild Devil), Saint Somewhere Brewing, Surly Brewing Company
Surly Brewing Company
The Surly Brewing Company is a Brooklyn Center, Minnesota-based craft brewery. Surly has a projected production of over 15,000 barrels in 2010...
(in their Pentagram and Five), and Avery Brewing Company (in Depuceleuse).
While most stout
Stout
Stout is a dark beer made using roasted malt or barley, hops, water and yeast. Stouts were traditionally the generic term for the strongest or stoutest porters, typically 7% or 8%, produced by a brewery....
s achieve their sour tang through the use of acidulated malt, roasted barley, or — in the case of "milk stouts" — lactose
Lactose
Lactose is a disaccharide sugar that is found most notably in milk and is formed from galactose and glucose. Lactose makes up around 2~8% of milk , although the amount varies among species and individuals. It is extracted from sweet or sour whey. The name comes from or , the Latin word for milk,...
and incipient lactic acid, some use Brettanomyces for the same purpose. Prior to 1980s-era changes in its fermentation regimen, Guinness
Guinness
Guinness is a popular Irish dry stout that originated in the brewery of Arthur Guinness at St. James's Gate, Dublin. Guinness is directly descended from the porter style that originated in London in the early 18th century and is one of the most successful beer brands worldwide, brewed in almost...
's Foreign Extra Stout is held to have been one such.
See also
- 4-ethylguaiacol
- 4-Ethylphenol4-Ethylphenol4-Ethylphenol, often abbreviated to 4-EP, is a phenolic compound with the molecular formula C8H10O. In wine and beer it is produced by the spoilage yeast Brettanomyces. When it reaches concentrations greater than the sensory threshold it can give the wine aromas described as barnyard, medicinal,...
- Brettanomyces bruxellensisBrettanomyces bruxellensisBrettanomyces bruxellensis is a yeast native to the Senne valley near Brussels, Belgium. It is one of several members of the genus, which was discovered at the Carlsberg brewery in 1904 by N. Hjelte Claussen, who was investigating it as a cause of spoilage in English ales, hence the name...
- LambicLambicLambic is a very distinctive type of beer brewed only in the Pajottenland region of Belgium and in Brussels itself at the Cantillon Brewery and museum...
- Wine faultWine faultA wine fault or defect is an unpleasant characteristic of a wine often resulting from poor winemaking practices or storage conditions, and leading to wine spoilage. Many of the compounds that cause wine faults are already naturally present in wine but at insufficient concentrations to adversely...