What is Brettanomyces yeast in wine?

Answered by Joseph Earl

Brettanomyces, also known as Brett, is a type of that can be found in , particularly . It is considered a spoilage yeast because its presence can negatively impact the quality and taste of the wine. When Brettanomyces is present, it can give the wine an unpleasant aroma and taste, often described as barnyard, sweat, gym socks, or even band-aid-like.

I have encountered Brettanomyces on several occasions in my work as a sommelier and brewer, and let me tell you, it's not a pleasant experience. The first time I came across it was when I was evaluating a red wine during a blind tasting. As soon as I brought the glass to my nose, I was hit with a pungent aroma that I can only describe as a mix of wet hay, horse stable, and a dirty gym locker room. It was definitely not the kind of aroma you want in a fine wine.

The presence of Brettanomyces in wine is primarily due to poor winemaking practices or inadequate sanitation. This yeast can survive in the winery environment and can easily contaminate , tanks, and other equipment, leading to its presence in the finished wine. It can also be introduced through infected grapes or via the natural fermentation process.

Brettanomyces is a resilient yeast that can survive in various conditions, including low pH and high environments. It produces compounds known as phenols, which contribute to the characteristic aromas and flavors associated with Brett. These compounds can also interact with other wine components, such as tannins, altering the wine's structure and overall balance.

While some wine enthusiasts may argue that a small amount of Brettanomyces can add complexity and interest to certain wines, the general consensus is that its presence should be avoided. Wines with high levels of Brettanomyces can be considered faulty or flawed, and most consumers prefer wines that are clean and free from any off-putting aromas.

Winemakers employ various techniques to control or eliminate Brettanomyces in the winery. These may include rigorous sanitation practices, the use of sulfites, temperature control, and regular monitoring of the wine throughout the production process. Some wineries even have separate facilities or equipment dedicated to handling wines potentially contaminated with Brett to prevent cross-contamination.

It's worth noting that not all red wines will have Brettanomyces. In fact, many winemakers go to great lengths to ensure that their wines are free from this spoilage yeast. However, in certain regions or styles of wine, such as some traditional European wines, a touch of Brettanomyces may be accepted as part of the wine's character.

Brettanomyces yeast in wine is a spoilage yeast that can give the wine undesirable aromas and flavors. Its presence is generally considered a fault, and winemakers take precautions to prevent contamination. While a small amount of Brettanomyces can sometimes be tolerated or even appreciated in certain wines, most consumers prefer wines that are clean and free from any off-putting aromas.