No such thing as wild yeast fermentation? Total nonsense. (These are Wark's words, not Lange's, so far as I know).
I'm not disputing that the BC study found what it found, nor am I saying that the data were mishandled. I am saying that other studies have shown that there is such a thing as wild yeast fermentation. So say the scientists, not Teh Natural Wine Taliban.
Y'all remember this study: Gayevskiy and Goddard analyzed 274 different genotypes of S. cerevisiae isolated in NZ vineyards with the database of 79 commercial wine strains commonly used in NZ, but only seven of the 274 genotypes closely resembled a commercial strain (see
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3379632/). They conclude, "spontaneous ferments are not driven by 'escaped' commercial isolates, even in large commercial wineries that also run parallel inoculated ferments (as was the case here), but driven by a diversity of natural isolates."
Constanti et al (Am. J. Enol. Vitic. 1997) found that "S. cerevisiae MF01 [the yeast used in year one of the study to inoculate] competed with indigenous strains in both fermentations during the second year (uninoculated Garnatxa and inoculated Xarel.lo musts), although it did not completely suppress their growth. MF02 and MF03, mainly present in Garnatxa must, dominated this fermentation at different stages." So noncommercial yeasts made headway and competed with commercial yeast. This suggests that, over time, indigenous strains of S. cerevisiae could compete with or overtake ambient commercial yeasts in a winery, should the winemaker choose to stop inoculating.
And then Torija et al ("Yeast population dynamics in spontaneous fermentations: Comparison between two different wine-producing areas over a period of three years,"
http://www.ncbi.nlm.nih.gov/pubmed/11816978) found that in four wineries that had never used starter cultures, S. cerevisiae populations changed from year to year. The number of strains found during fermentation in each area in one year was around 30, yet over the course of three years, 112 strains were identified. Over the years, strains came, strains went. Moreover, no single strain dominated throughout fermentation. Rather, new strains of S. cerevisiae were found at various stages of the fermentation, while some strains that had been found during the early stages were not to be found in later stages.
To recap: S. cerevisiae strains in the wild have been found to mostly differ from their commercial cousins; wild strains may eventually dominate over commercial strains if a winemaker chooses to stop inoculating; and if you don't overwhelm your must with one or two or three strains of commercial yeast, then perhaps 30 indigenous strains will act upon the must. Which means to me that the notion that there's "no such thing as wild yeast fermentation" is total nonsense.
