What is a common sign of a wine fault related to Brettanomyces?

The presence of a barnyard or horsey aroma is a well-known indicator of Brettanomyces, a type of yeast that can cause faults in wine. This particular aroma arises from the volatile phenols produced by Brettanomyces during fermentation and aging. These compounds impart distinctive smells that can be reminiscent of barnyard, leather, and even horse sweat, leading to a sensory profile that many find undesirable. While Brettanomyces might contribute some complexity in limited amounts, when it dominates, it significantly alters the wine’s intended character and quality.

Fruity aromas and excessive sweetness are generally associated with well-crafted wines, highlighting the primary characteristics of grape varieties. A metallic taste typically suggests issues related to the wine's bottling or storage conditions and is not associated with Brettanomyces activity. Understanding these nuances helps wine professionals recognize faults and educate consumers about wine quality.