Doctor's Review: Medicine on the Move

December 6, 2021

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Wild at heart

For bakers and winemakers, uncultured yeast has become the holy grail

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 organisms to be domesticated, some 6000 years ago. Now, some say they are instigating fistfights. The interlocking worlds of bread and wine are clashing over the choice of 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, the chief winemaker at Keint-he Winery and Vineyards (49 Hubbs Creek Road, Wellington, ON; in Prince Edward County, Ontario. “There’s the interventionist approach and there’s the hands-off approach. And both sides can be ridiculously bombastic.”

Organic organisms

Wild or ambient yeasts inhabit wineries and vineyards, often carried by insects such as fruit flies, and introduce complexities of flavour and texture as they work their wonder in the early stages of fermentation. They die when the wine reaches a low-alcohol level of about five per cent (wine will typically continue to 12 to 14 percent) then give way to the species of Saccharomyces cerevisiae — which occurs naturally and is also the commercially produced variety — that takes over and finishes the process.

The alternative, inoculating crushed grapes with commercially produced yeast, promises speed, expediency 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.

Popular British wine journalist Jamie Goode writes on his blog “Simplistically, interventionist winemakers can use specific varieties of cultured yeast to alter wine style; traditionalists prefer to use either natural yeasts, or neutral cultured yeasts; and some winemakers even consider the native yeast present to be part of the terroir of the wine.” Heinricks, author of A Food and Forty Acres and an early pioneer in Prince Edward 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.”

Heavenly leaven

Most industrial and even so-called artisanal breads are made with commercial yeast and have been for decades. It’s easier, faster and more predictable. Jeff Connell of Woodlot Bakery and Restaurant (293 Palmerston, Toronto, ON; in Toronto is grateful for the opportunity to use wild yeast. “I don’t quarrel that you can make wonderful bread with commercial yeast,” he says. When the restaurant opened last year, he didn’t rule out using it but discovered he didn’t need it. “I maintain a sourdough culture. I’m looking for a long, slow fermentation because time equals flavour,” he says. The results have a fanatic following in the city that means the bread is pretty much guaranteed sold out. “It has good spring, good life, a nice crumb.”

Still, there are challenges. “The schedule can be inconvenient,” says Connell, who starts work at midnight, when the restaurant is closing, and finishes around noon. “And the mother-dough needs to be kept in balance. It happened once when we closed over the week at Christmas, the mother-dough became somewhat volatile. It took a few days to get it right again.”

Connell and Heinricks also emphasize the importance of raw ingredients, which they say are the cornerstones that invite wild yeast to thrive. Connell uses certified organic Red Fife wheat and other organic grains, preferably open-pollinated traditional varieties, from CIPM Farm near Belleville, Ontario and white flour from an organic farm and mill in Alberta.

The other ingredient is water, which is Toronto tap that Connell runs off the day before “on the theory that chlorine dissipates. Ideally I would like to try to replicate water of a mountain stream, maybe one day.”

Modified risks

The team at Keint-he Winery uses strictly organic Pinot grapes, all locally grown on the estate’s vineyards, then hand-tends the vines, practises traditional Burgundian approaches to high-density vines and produces on a small-domain level of about 1000 cases, since their first vintage in 2007, and to as many as 2500 last year.

There’s another reason purists are looking to preserve the ancient existence of wild yeast: soon, it could become a thing of the past. Earlier this year, a genetically modified (GM) yeast for winemaking, developed at the University of British Columbia and called ML01, was approved by Health Canada. It’s already legal in the US and South Africa, banned in Australia and required to be on labels if used in the EU.

If it is used in Canada, no one need know. Goode, a scientist, comments on his website: “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.”

He goes further and advises banning the use of GM organisms in winemaking. 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.” Not that wine itself would disappear, but that particular magic created by wild yeast could be lost to us.

This article was accurate when it was published. Please confirm rates and details directly with the companies in question.


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