Wild Yeast May Tame Blockbuster Wines
If wines with alcohol levels approaching port don’t sit well with your taste buds or sobriety, scientists at the Australian Wine Research Institute at the University of Adelaide may have just the solution you’ve been looking for.
It’s a strain of the Metschnikowia pulcherrima yeast that produces less alcohol from the same amount of sugar in grape juice than the predominant yeast, Saccharomyces cerevisiae. Anyone who’s bought more than a couple bottle of wine over the past several years has seen alcohol levels creeping up. Wines with 12.5 or 13 percent alcohol were once commonplace. Now they’re at the low end of the alcohol spectrum, with both red and white varietals pushing and even exceeding 14 and 15 percent.
Though this alcohol inflation has mellowed somewhat in recent years, with growers and winemakers employing various techniques to reduce alcohol levels and produce wines of greater elegance and restraint, some of these techniques can adversely affect the flavor of wine, especially when consumers tend to gravitate to robust, fruity, ripe-tasting wines.
The M. pulcherrima yeast was isolated from 50 strains of wild yeasts, then tested on Chardonnay and Shiraz grapes, reducing alcohol levels by almost 1 percent in the former and 1.6 percent in the latter. In terms of flavor, however, results were more mixed, with Chardonnay developing much higher levels of ethyl acetate, producing the dreaded “nail polish remover” effect. Shiraz, on the other hand, responded more favorably, with initial tasters reportedly finding it fruitier and more complex than wine produced with the S. cerevisiae yeast.
Of course, you could dilute your wine with a little water or just drink less, but that doesn’t sound like very much fun.