What's the deal with Brettanomyces

What's the deal with Brettanomyces

Brettanomyces (Brett) is a type of yeast commonly identified as a fault by modern winemakers but also responsible for tertiary fermentation in Lambic and Flanders red ales. So it tastes good in beer and terrible in wine? So it would seem.

Many craft brewers are purposefully using it to gain complex characteristics in their beers.The genus of Brettanomyces has five species, two are currently used in brewing, Brettanomyces Bruxellensis and Brettanomyces Anomalus. Brettanomyces is hard to control, and even harder to predict. In beer Brettanomyces can create esters, ethyl caproate and ethyl caprylate, which can produce floral or fruity, pineapple, apricot, tropical fruit aromas. Volatile phenols are another group of compounds and can lead to clove aromatics or horsey, medicinal aromas. Sweaty saddle anyone?

In the wine world Brettanomyces has been a controversial topic. Many of the most highly acclaimed wines and wine regions have long claimed that their wines tasted the way they did because of 'terrior', it was unique and special. Of course now we have developed scientific tests that can accurately identify the existence, or not, of the yeast. So it was probably poor hygiene in the winery which is far less appealing. It is quite a challenge to convince a French winemaker from Bordeaux or the Rhone Valley that their very expensive wines are in fact faulty.

Wine can be affected by Brett in similar ways to beer, but with aromatic compounds 4-Ethylphenol and 4-Ethylguaiacol, commonly shortened to 4-EP and 4-EG, the most common. In general, 4-EP is responsible for Band-Aids and manure, while 4-EG accounts for the more traditionally pleasant aromas of clove and spice. But Brett not only adds to a wine, it also subtracts. Brett produces enzymes that break down esters in wine, diminishing the impression of fruitiness. It can also affect texture by feeding on unfermentable and oak sugars rendering the acidity more angular, the tannins more aggressive.

Too much of anything is bad, it is argued that in small enough concentrations Brettanomyces can be pleasant. There is no shortage of very popular and highly rated Brett affected beers and wines to confirm this must be the case for some people.

If you are curious and want to know if Brettanomyces is for you we have a couple of great products at the moment. A session ale from Garage Project in NZ fermented with Brettanomyces and saison yeast called Petite Mort. A Cabernet Franc from Mallaluka is made using the carbonic maceration method and has intense vibrant black fruit flavours, these meld with just the faintest hint of spicy, funky Brett characteristics.

- Chris, Albury -