Wild Yeast Fermentation: “There’s No Such Thing”
Some fairly stunning information concerning the idea of “Wild” or “Indigenous” yeast is coming to light that has implications for wine marketing and wine making. How shall I put this? Let’s try this: If you think your wine went through fermentation driven by wild yeast or if you think the wine you are drinking was produced via a wild yeast fermentation, it probably wasn’t.
This is the startling conclusion brought to light in a study undertaken in British Columbia and reported upon by Andy Perdue in the new August 2013 issue of Wine Business Monthly. Here’s the money quote:
AMAZING
The results of the three years study of three wineries in British Columbia under the auspices of the University of British Columbia were first disclosed at a talk given at last summer’s British Columbia Wine Grape Council’s Annual Meeting.
The esteemed Ken Wright of Ken Wright cellars described what he heard at the meeting as “Amazing”, and went on to note that the findings “flew in the face of what I and most people were assuming happens in fermentations…Wild fermentations are anything but wild. Yes, you have a strain that is identified as wild. But that strain is almost immediately overwhelmed by house yeast. Within the first few days of fermentation, they are gone. The commercial strains fight it out for domination.”
QUESTIONS
The questions, then are these: will commercial strains take over a fermentation in a winery where no commercial yeast has ever been used before? Even if you have never used a commercial strain of yeast, will your “wild” fermentation be overtaken by a dominant commercial strain if you are producing wine in a region where commercial strains have been used by other wineries and that become part of the regional environment (terrior)?
Wright is organizing a similar study in Oregon that will include Penner-Ash Wine Cellars, Beaux Freres, Grand Cru Estates, Cristom and Bethel Heights Winery. Also, Road 13 Vineyards, one of the original 3 wineries involved in the study, is in the process of building a new facility that will never have had a commercial yeast used in its proximity. They will test for which yeast strains are present in their first fermentations, further clarifying these startling results.
IMPLICATIONS
It’s notable that among the primary criteria to be called a “Natural” wine, is that the yeast used must be “wild” or “indigenous to the vineyard/winery. If these findings appear to be consistent across the globe’s growing regions, “Natural” winemaker may have to rethink what they consider necessary in order to call a wine “Natural”. Futhermore, numerous wines are marketed as being produced with “Wild Yeast”. Again, if these findings are consistent across growing regions, there may be a need to stop such marketing or make it easy and simply re-define what “wild” means.
For he record, the leader of the study reported upon in Wine Business Monthly, Dan Durrall, believes “there is no such thing as a ‘wild yeast’ fermentation.”

Another question is…the dominant ‘commercial’ yeast strains mentioned in the article have always been marketed to winemakers as specifically isolated for wines (and even for specific wines). If it turns out that these strains are taking over even in new cellars where no yeast has ever been used, then it would seem that the previous marketing of said yeast strains might be…shall we say…charlatanesque?
As fermentation facilities are not “clean rooms” in the industrial-control sense, they are not excluding house yeast. In as much as that we can isolate wild yeast, and cultivate it in an environment where no other yeasts are present, it’s not exactly wild but newly domesticated.
Rich,
I can see the language on the label of that cold climate Pinot now:
PINOT NOIR
Russian River Valley
“Hipity Dipity Vineyard”
Newly Domesticated Yeast
It doesn’t quite have the ring, does it.
let me know when we have a final definition on natural wine…..
William,
I’m on it.
“oh I hope the terroir of my land comes thru with my natural occurring yeast after I inoculate with this commercial yeast strain that gives me the specific taste and color profile I am after…” has said no wine maker ever, at least any that knows what they are doing.
This read as one massively biased “study”. The jump to an assumption or question that because somebody uses commercial yeasts means it could take over all other yeasts in a given region is a pretty big leap.
I got it. If ‘wild’ is techincally disingenuous marketing, & ‘newly domesticated’ is awkward labeling, my own unevenly yeasted life provides a category source model: RANDOM. I prefer wines fermented by RANDOM YEASTING to those inoculated the the lab-hand of man– MOST of the time. Thank you.
The lab-hand of this man at work: techincally, for ‘technically’!
This argument is idiotic. Where do you thinik “commercial” yeast strains come from? They isolated the dominant yeast strains, then packaged them. Twenty years later, they notice that all the dominant yeast strains are “commercial” yeast strains, and therfore say there is no such thing as wild fermentation? That’s like saying all wild animals are domesticated in zoos, so therefore there is no such thing as a wild animal.
The idea behind “wild” yeast fermentation is that during the first week of fermentation, an ecosystem of various yeasts and bacteria will develop before the dominant yeast takes over. Experiments have been done to prove that “wild” ferments have a wider variety of yeast and bacteria than wines that are made with commercial yeasts.
Gabe:
Regarding the wild animal analogy. That’s not really what’s being said. a “Wild Yeast” fermentation always refers to allowing whatever yeasts are ambient to have their way. No one is saying there does not exist yeasts beyond those cultivated. However, many folks that promote wild yeast fermentation do so with the thought that having cultivated yeasts do the work leads to a lack of authenticity. It’s likely that many of these folks are simply watching their wines ferment with dominant, cultivated yeasts that floated their way.
And you are correct. “Wild Yeast” fermentations do indeed have a wider variety of bacteria. In fact, you risk a great deal by going with straight wild yeast fermentations because of the soup of bacteria that can result.
One interesting question is to what extent any discernible character can be created from the short time the non-dominant yeasts help the ferment out in the very, very early stages.