Is There Such a Thing As Wild Yeast Fermentation?

You have undoubtedly heard the words "wild," "natural," or "indigenous yeasts" over the last few years, as it has become quite to go to descriptor amongst some in the wine business. Essentially, it means the wine makes itself, there is no inoculation. So whatever yeast is already in the air (or on the clusters) starts the fermentation process. Many have argued that this way is the purest expression of the wine. Well, now we have some evidence that this idea of "wild" yeast may not even exist to its full extent. The fermentation may in fact start indigenously, but commercial yeasts eventually take over and dominate the fermentation, thereby eliminating the once "wild" yeasts.

In the August issue of Wine Business Monthly, the headline reads:  

Study Indicates Commercial Yeast Strains Take Over Fermentation - The yeast strain you think is fermenting your wine probably isn't doing the job- unless it is a dominant commercial strain.

The start of the story:

"That exotic yeast you used to ferment your wine? It probably didn't. That wild yeast fermentation you prefer? It probably isn't. So suggests three years of research at the University of British Columbia (UBC) in Canada. "The winemaker assumes that what they inoculate with is what they get in their fermentations," said Dan Durall, a biology professor at the University of British Columbia, Okanagan in Kelowna, British Columbia, who has led the research since 2010."

 More here:

"His investigation indicates that likely is inaccurate: The yeast strain you think is fermenting your wine probably isn't doing the job-unless it is a dominant commercial strain. The study began in 2010 when graduate student Jessica N. Lange spent time at three Okanagan Valley wineries to study yeast during multiple stages of fermentation in Pinot Noir. Lange collected samples during cold soak then during early, mid and late stages of fermentation."

"What she found was startling: Regardless of which yeast started the fermentation-indigenous or otherwise-a dominant commercial strain took over during the process, essentially wiping out any other forms of yeast that might have been present, Durall said."

The full story can be read here (in PDF form): Full Yeast Story

Create an informed opinion.