{"id":653,"date":"2013-04-21T18:02:00","date_gmt":"2013-04-21T18:02:00","guid":{"rendered":"http:\/\/suigenerisbrewing.com\/index.php\/2013\/04\/21\/introducing-brettanomyces\/"},"modified":"2017-09-15T18:53:54","modified_gmt":"2017-09-15T18:53:54","slug":"introducing-brettanomyces","status":"publish","type":"post","link":"https:\/\/suigenerisbrewing.com\/index.php\/2013\/04\/21\/introducing-brettanomyces\/","title":{"rendered":"Introducing Brettanomyces"},"content":{"rendered":"

As I have mentioned previously, part of my Hunting Wild Yeast<\/a> project is writeups describing the more common yeast and bacteria that are found in sour beers & wild ferments. In my last article I wrote about the typical pattern of yeasts and bacteria observed in wild ferments<\/a>. In this article I’m going to cover the basic characteristics, flavour profile, and purification of Brettanomyces<\/i> yeasts.<\/p>\n

Brett<\/i> was discovered by N. Hjelte Claussen in 1904, and was identified as the causative agent in producing the characteristic flavour of old English ales. Brettanomyces<\/i> is literally Greek for “British fungus”. Of the wild yeasts, Brett<\/i> is the best known and most widely used. Indeed, Wyeast and White Labs both carry a range of well characterized Brett<\/i> strains, meaning that at least some Bretts<\/i> are no longer wild.<\/p>\n

Brett<\/i> adds some unusual flavours and aromas to beers. Describing some of these to people who have not worked on farms is difficult – Brett<\/i> can give off an aroma of an old horse blanket or a sweaty horse; I cannot think of a good replacement, but a musty old wool seater with hints of dust and sweat might be close. Other flavours such as stale\/mousey, leather, band-aid\/plastic, enteric (vomit), burnt protein\/beans, and peppery also describe some of the flavours associated with Brett<\/i>. To many these sound unpalatable – indeed, in many beers and wines the presence of Brett<\/i> is a flaw. But managed properly, these yeasts can provide a novel and interesting set of flavours to a beer brewers ensemble.<\/p>\n

More below the fold…
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Evolutionarily speaking, Brett<\/i> is a close relative to our old friend Saccharomyces<\/i> – indeed, they belong to the same family of yeasts. Brett<\/i> and Sacch<\/i> went their separate evolutionary ways around 230 million years ago; despite that they are not overly different. The are roughly the same size and shape, reproduce through budding, are strong fermenters, and can survive in high alcohol environments. But Brett<\/i> has picked up some unique metabolic tricks over the years, leading to some unique characteristics.<\/p>\n

What Brett Adds to Beer:<\/i><\/b>
\nThe first of these is the ability to ferment a broader range of sugars than normal yeast – indeed, Brett<\/i> can consume some of the sugar-based polymers found in wood, which is what allows Brett<\/i> to inoculate wine barrels and corks – leading to the cork taint<\/a> feared by many vintners. This same capacity allows Brett<\/i> to consume many of the dextrins that Sacch<\/i> will leave in a beer. As such, Brett<\/i> beers often have very low final gravities – in some cases below 1.000. Because of this, Brett<\/i> is rarely used in low-alcohol beers, as it leaves the beer thin and insipid. Generally, Brett<\/i> is limited to beers with a gravity above 1.060, with the exception of Lambics and Berliner Weisse. Because Brett<\/i> will digest most dextrins, higher gravity beers become winelike (vinous) and dry.<\/p>\n\n\n\n\n
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4-Ethylguaiacol
\nFrom wikipedia<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Aside from the ability to eat a much broader range of carbohydrates than Sacch<\/i>, Brett<\/i> also produces many unique flavour compounds. The most desired\/common are phenol compounds – these include 4-ethylphenol (barnyard\/horse blanket; band-aid), 4-vinylphenol (mousey\/barnyard) and 4-ethylguaiacol (spicy\/peppery, cloves, smoke). Brett also produces some fatty-acid derived compounds including isovaleric acid (rancid\/cheese), isobutyric (buttery) and 2-methylbutyric acid (sweaty\/cheesy). In the presence of oxygen – even small amounts – Brett<\/i> will produce acetic acid (vinegar), providing an acidic finish to the beer. \u00a0The contribution of Brett<\/i>\u00a0to acidity is usually small; very sour beers gain their acidity from the activity of bacteria such as lactobacillus<\/i>.<\/p>\n

Brettanomyces Species:<\/i><\/b>
\nAt this time there are five identified species of Brettanomyces<\/i> – B. bruxellensis <\/i>(which includes B. lambicus<\/i> & custersii<\/i>), B. anomalus<\/i> (which includes B. claussenii<\/i>) plus three non-brewing species B. custersianus\/naardensis\/nanus<\/i>. To make life complicated, Brettanomyces<\/i> are also sometimes called Dekkara<\/i>; two names for the exact same thing. The three primary fermentative strains (bruxellensis\/<\/i>lambicus\/claussenii<\/i>) have very different characteristics:<\/p>\n