The process of creating beer, wine and spirits that are not only delicious, but non-toxic, is extremely scientific; one step in the wrong direction and you could end up with a skunked batch or even a lethal dose. That’s why there are hundreds of resources outlining the specific needs of a variety of alcohol categories, leaving nothing to chance in a sterile and calculated environment. But some brewers, vintners and distillers are starting to lean back into the natural process, and the results speak for themselves.
While as a species, humans have been making alcohol for thousands of years, it wasn’t until the 1840s, that scientists identified yeast as the cause of fermentation and since that discovery, the best strains have been commercially cultivated to create a consistent, reliable product.
Recently however, there’s been a growing trend of reintroducing a wild element of fermentation back into the process, which can produce some significantly unique elements, albeit with high risk. The problem is when you work with wild yeast you’re betting on the science of nature, and nature can be highly unpredictable.
Here’s how wild yeast is being reintroduced into several different categories of alcohol:
Craft beer coolships & wild aging
Craft beer is probably the category that has embraced the wild yeast trend the most, with many brewers utilizing either coolships, wild barrel aging or a combination of both to create final products they would otherwise be unable to achieve.
Wild yeasts in beer can be incredibly dangerous, as wild yeast is unpredictable, cross contamination with any of the other beer being made would cause infection and ruin those batches. Therefore most brewers tend to keep their wild yeast barrels or coolships far away from the rest of the brewing facility.
Traditionally, a coolship is a broad, open-top, flat vessel made of copper in which wort cools. The open air allows for wild yeast to permeate the wort while it cools allowing for spontaneous fermentation. This produces a beer with a more tart and acidic flavour, which is generally then allowed to age in a barrel to produce some fantastic lambics, sours and geuzes.
The process for wild barrel fermentation is similar, in that a brewer will follow a traditional technique to create a wort, and then introduce a wild yeast strain into the final fermentation process and allow the beer to sit, sometimes for several years, so the yeast can mature and create a sour beer that cannot be replicated any other means.
Some Canadian breweries that have embraced the wild yeasts are BC based Strange Fellows and Four Winds or Ontario based Beau’s Brewery.
Open air fermented spirits
Spirits are a category that you’d think requires precision and control, especially over the yeast and fermentation process. But those that take the risk with wild fermentation can see some unique results.
Herradura tequila is one such producer that despite being one of the oldest tequila producers in Mexico, their distilling process is wholly dependent on wild and open air fermentation. While that seems crazy, there is in fact a method to the madness.
Each fermentation tank is open to the surrounding air, and strategically placed around the property are a variety of fruit trees like mango, orange, lemon and lime. Overall there are 16 different types of fruit trees at the Casa which produce 300 different strains of yeast to float around in the air. The natural yeasts from these trees migrate into the fermentation tanks, which results in lingering notes of these fruits in the final product.
When it comes to wine production, most wineries will ensure there grapes are sterile before reintroducing specific yeast strains back in to the fermentation process.
But in Canada, several wineries have embraced natural fungus and are betting big on the wines produced. Okanagan Crush Pad (OCP), along with other wineries like Kelowna’s Summerhill Pyramid Winery, Niagara-on-the-Lake’s Southbrook Vineyards and Jordan, Ont.’s Pearl Morissette, harness the power of microbes living in the vineyard. After grapes are picked, they’re crushed and left to ferment with the microflora living on their skins.
The finished product tends to be a little hazy and far more complex than your general wine, and as these tend to also be unfiltered, there’s an ongoing transition occurring in the bottle. If you don’t like the first taste, put the bottle back in the fridge and you’ll have a completely different flavour the next day.
Clearly there is a lot risk working with wild yeast, but with risk comes reward as many producers are starting to discover. As consumers begin to demand more complexity with their alcohol, wild yeast offers an opportunity to create a defined product that stands out from the competition.