They are airborne, free for the taking—and lately, highly contentious. Wild yeasts, a traditional ingredient in making wine and leavened bread, were arguably the first micro-organisms to be domesticated, some 6,000 years ago. Now, they’ve got people locking horns. The bread and wine worlds are clashing over who goes native with the naturally occurring stuff and who opts for using common cultivated varieties. “Basically it’s sort of a culture war, like in the United States,” says Geoff Heinricks, Keint-he Winery and Vineyard’s winemaker, based in Ontario’s Prince Edward County: “Both sides can be ridiculously bombastic.”
Wild or ambient yeasts inhabit wineries and vineyards, often carried by insects such as fruit flies, and introduce complexities of flavour and texture in the early stages of fermentation. They die when the wine reaches a low-alcohol level of about five per cent (wine is typically 12 to 14 per cent), then give way to the species Saccharomyces cerevisiae—it occurs naturally and is also the commercially produced variety—that finishes the process.
The alternative, inoculating crushed grapes with commercially produced yeast, promises results of speed, expedition and predictability, or standardization. This practice took off with the demand for New World mainstream wines in the 1970s and is still the mainstay in these markets, although there’s an increasing fringe interest among major producers in making small-batch wines that are labelled “wild-yeast” vintages and generally come with a higher price tag. “Like a marketing thing, splashing it on the label,” says Heinricks.
Heinricks, author of A Fool and Forty Acres and a pioneer in County wines, subscribes to the practice of natural yeast and slow fermentation. “It comes down to what you’re looking for: a bland manufactured corporate beverage or something enticingly familiar yet hauntingly unique. Something made from your corner of the world,” he says. “It’s the same way with good bread, tasting different elements. We all like to be a little astonished.”
Most industrial and even so-called artisan breads are made with commercial yeast and have been for decades. It’s easier, faster and more predictable. Jeffrey Connell of Woodlot Restaurant in Toronto is grateful for “the opportunity” to use wild yeasts, though, “I don’t quarrel that you can make wonderful bread with commercial yeast.” He maintains a sourdough culture, explaining, “I’m looking for a long, slow fermentation because time equals flavour.” The results have a fanatic following. Still, there are challenges. “The mother dough needs to be kept in balance,” says Connell. “It happened once when we closed over Christmas, the mother dough became somewhat volatile. It took a few days to get it right again.”
Connell and Heinricks also emphasize the quality of raw ingredients, which they say are the cornerstones that invite wild yeasts to thrive. Connell uses organic Red Fife wheat and other organic grains, preferably open-pollinated varieties, from CIPM farm in Ontario, and white flour from an organic farm and mill in Alberta. The team at Keint-he uses strictly organic Pinot grapes, all locally grown on the estate’s vineyards, and tends the vines by hand.
There’s another reason traditionalists are looking to preserve wild yeasts: soon, they could become a thing of the past. Earlier this year, a GM yeast for winemaking, developed, in part, at the University of British Columbia and called ML01, was approved for commercial use by Health Canada. It’s legal in the U.S. and South Africa, banned in Australia, and awaiting approval in the EU. If it’s used in Canada, no one need know. Popular British-based wine journalist and scientist Jamie Goode comments in his new book Authentic Wine: “If GM yeasts become widespread, the danger is that wine will be seen as just another manufactured beverage. If we kill the ‘naturalness’ of wine, we run the risk of destroying the whole venture.” As Heinricks says, given the fact that yeasts do circumnavigate the globe, “they’re impossible to contain. So we could be on the verge of destroying what got mankind happily drunk for thousands of years.”