brettanomyces; brett [breht-tan-uh-MI-sees; BREHT]
brettanomyces is a spoilage yeast that produces a horsey, barnyard aroma that some people love (saying it adds richness to the wine), others detest, and many don’t even detect. It’s typically caused or by less-than-sanitary barrels or winemaking procedures. Other odor descriptors for wine degraded by brett include mouse droppings, a sweaty saddle, or burnt beans. A wine overly imbued with brett tends to get worse as it ages. Because brettanomyces (brett, for short) is almost impossible to eradicate, most winemakers take great pains to avoid it. When it does occur, vintners generally use special filters to reduce the prospect of continued growth in the bottle. Low levels of this pesky yeast can add complexity to a wine’s aroma, while overt amounts can ruin it. An organism called dekkera is virtually identical to brettanomyces and produces the same odoriferous results.
The New Wine Lovers Companion, 2nd Edition, by Ron Herbst and Sharon Tyler Herbst. Copyright © (1) 2003, 1995 by Ron Herbst and Sharon Tyler Herbst. Reprinted by arrangement with Barron's Educational Series, Inc.