Centuries ago, before brewers had figured out exactly what yeast was, or that it even existed, brewing was a rather unpredictable affair.

After they’d made what was essentially a tea from malted barley, they’d add some hops (or other herbs they had lying around), and then they’d wait and hope. Sometimes, after a few weeks, months, or even years, they’d have something drinkable which, with any luck, would make someone who imbibed it a little bit merry.

Quite frequently, however, their efforts would amount to nothing. The liquid would turn to a mouldy sludge or a horrid, vinegary mess.

Today brewers realize yeast is an essential part of the brewing process, which takes the sugar in malted barley and turns it into alcohol and carbon dioxide. They deliberately add strains of yeast to the sweet liquid known as wort, with some assurance that it will be transformed, more or less, into beer.

Now, a group of Ontario brewers are turning back the clock. They’re making a “wild” beer, which they’re hoping will spontaneously ferment using ambient yeasts which just happen to drift into the brew. While a few ardently traditional Belgian brewers use the same principle to create “lambic” style brews, it’s not exactly a technique that’s sweeping through the brewing industry.

“This is 15th-century old school,” said Jason Fisher, owner of Indie Alehouse, a new brew pub in the Junction, where five brewers came together one recent day to create the wort (basically, the unfermented beer) for their unusual brew.

The following day, they trekked down to the Niagara region, carrying their precious liquid cargo with them. Once they arrived at the Good Earth Winery in Beamsville, they set up their open brewing tanks in the vineyards, and left them overnight (actually, for about 18 hours) among the Cabernet Franc vines.

The idea, says Iain McOustra of Amsterdam Brewing, was that wild yeasts in the air would float into the open-topped tanks, and start to go to work on the wort. (In case you’re worried about birds or squirrels having made their way in, the brewers babysat the tanks the entire time).

“There’s wild yeasts all over the place in Niagara because of all the fruit, but we decided to go during harvest season, because the wild yeast would be getting disturbed, so there’d be more of it in the air,” said McOustra.

After the visit to wine country, the still-nascent brew was brought back to Toronto, and put into freshly-emptied wine barrels (from Featherstone Winery). It’s currently sitting in cold storage at Great Lakes Brewing in Etobicoke. That’s just where it will stay for the next few years. Eventually, Fisher, McOustra and their collaborators — Sam Corbeil of Sawdust City Brewing, Mike Lackey of Great Lakes and Jeff Boeders of Indie Alehouse — plan to blend different vintages of their “Niambic” together.

That is, admits McOustra, if it turns out.

“I’m pretty confident we’ll get something good. It had a lot of contact time with the yeast, and it seems to be fermenting like crazy right now, so we’ll see,” said McOustra.

josh@thestar.ca