- Spring 1998 "Update" Newsletter Article -
Seeking the Character of 'Brett'
Research team seeks chemical markers that will help winemakers identify common yeast
From CATI Publication #980401
Copyright © 1998. All rights reserved.
Wine microbiologists from the Eastern U.S. have joined those in the West to track growth habits of a yeast whose effects are hailed by some and despised by others.
California State University, Fresno winemaker Ken Fugelsang represents the western arm of the research team; nationally-known microbiologist B.W. Zoecklin of the Virginia Polytechnic Institute comprises the other. Both have placed a new emphasis on an age-old microorganism called Brettanomyces.
“Historically, winemakers have viewed Brettanomyces as a spoilage yeast, and its growth in wine as resulting in defect,” explained Fugelsang in outlining reasons for the study. “Despite traditionally negative connotations surrounding the yeast, many now question whether or not subtle ‘Brett’ character, in some cases, may play a positive role in flavor and bouquet development.”
Sensory descriptors of the “Brett” effect have ranged from spicy and smoky to medicinal, wet wool, and “mousy,” Fugelsang noted.
Renewed interest in “Brett” research has grown along with some philosophical changes in winemaking over recent years, Fugelsang said. More winemakers are interested in shifting from the common use of active dry yeast to original fermentation methods featuring use of native yeasts and bacteria arriving with the fruit, and/or present as part of the native winery flora.
Fugelsang and Zoecklin have identified at least 50 Brettanomyces strains, which means that wineries using “Brett” as part of their native yeast would likely see distinct flavor characteristics developing from the different strains.
Part of Fugelsang’s project is to establish some analytical standards for determining the presence of “Brett” in wines. To accomplish this, he has injected lots of the same wine with six strains of Brettanomyces intermedius.
Growth of the yeast and related compounds is being tracked in hopes of identifying chemical markers that confirm “Brett” effects.
Fugelsang conducted the initial phase of the work, overseeing crushing the grapes and clarifying the juice, then doing the innoculations. Zoecklin will oversee the analytical work with specialized equipment located at Virginia Polytechnic.
Sensory evaluations of the finished wine samples also will be conducted to determine whether trained tasters can detect consistent differences determined in the analytical process.
Results are expected later this year and will be presented at selected enology seminars and in print publications. For more information, Fugelsang may be contacted at (559) 278-2791.
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