In the days before stainless steel, beer was matured at the brewery in wood, often in large, pitch-lined barrels known as tuns. Occasionally, brewers used massive vats capable of holding half a million litres or more: In the Great London Porter Flood of 1814, one such container ruptured in the British capital, resulting in the death of eight people. Other brews were kept in much smaller barrels, and perhaps some of those had been repurposed from the Scottish whisky industry.
Whisky casks are typically used just two or three times, and subsequently filling them with ale would have bestowed varying degrees of whisky flavours upon the beer. This we know for sure, not because of idle speculation, but because barrel-aging beer is the latest thing in brewing, and many of the barrels being used come straight from Scotch whisky or bourbon distilleries.
Most famous of these is Innis & Gunn, the 11-year-old Scottish firm that was born of a distillery's interest in the opposite idea: aging Scotch in barrels that had been conditioned with beer. When the workers charged with emptying the barrels kept taking the wood-aged ale home, the decision was made to refine and market the beer, now known as Innis & Gunn Original. Less well known, but often more complex, are the company's other, more obviously whisky-wood-influenced brews, such as the oaky, herbal Rare Oak Pale Ale and the Scotch Whisky Porter, which has charred and vanilla notes that make it obviously born of the barrel.
Even greater barrel influence is found in the Ola Dubh – pronounced "Ola Doo" – ales from Scotland's Harviestoun, produced in association with the Highland Park distillery. Barrels that previously held malt whiskies of 12, 16 and 18 years of age are used to mature inky-black ales of similar vintage, creating a flavourful (and, at 8-per-cent alcohol each, somewhat boozy) sojourn from dark chocolate to whisky-soaked fruit.
Closer to home, Scottish whisky barrels are harder to get, but bourbon barrels are relatively plentiful, thanks to a regulation limiting their use to one fill only. As such, Canadian and American breweries are far more likely to age their brews in ex-bourbon wood than they are the Scottish stuff, producing much bolder beers that express the fruity intensity of the American spirit.
Gary Lohin oversees one of Canada's largest brewery barrel rooms at Central City Brewing in Surrey, B.C., with most of his 400 barrels having previously held bourbon. He's fascinated by the vanilla and caramel notes he gets from the wood, but also the way the barrels work.
"Each one is its own microenvironment," Lohin said. "Some barrels don't make the cut, producing beer that just doesn't taste good, while others taste amazing, even though you fill them with the same beer at the same time." For this reason, he says, they keep a very close eye on the aging beer, tasting regularly. Central City's bourbon-barrel-aged Thor's Hammer Barley Wine and Imperial Porter are just two of the barrel-conditioned beers brewed or available in Canada.
The country boasts a host of barrel-fuelled brews, from PEI Brewing's mellow and vanilla-ish Ice Boat; to the spicy, 25th-anniversary St-Ambroise Oak Aged Pale Ale by Montreal's McAuslan Brewing; to the soothing Deviator Doppelbock from Cameron's in Ontario. Notable American brews include the frustratingly rare Canadian Breakfast Stout from Michigan's Founders Brewing, which is conditioned in bourbon barrels that have first been used to mature maple syrup.
Some barrel-aged beers offer only hints of oakiness, while others might leave splinters between your teeth. All offer an experience miles from the everyday lager, well suited to the Canadian winter.
Four Bars Where You Can Get Your Oak On
This Sunday is Robbie Burns Day, an excellent reason to try a barrel-aged brew at one of these bars.
The Bristol – Although a mere eight months old, the Bristol has already become one of Innis & Gunn's top pubs, with the Original and non-barrel conditioned Lager always on tap. 1087 Queen St. West; www.bristolbombay.com/
Bar Hop – This craft beer bar always seems to stock the most interesting one-off and specialty beers Ontario's craft brewers have to offer, usually including one or two barrelled brews. 391 King St. W., Toronto; www.barhopbar.com
Alibi Room – An edge of Gastown mainstay, this comfortable pub has 50 taps stocked with an ever-changing array of exciting beers. 157 Alexander Street; www.alibi.ca
Vices & Versa – Quebec's craft brewers are crazy for barrels of all sorts, from whiskey to wine to cider. Many of the resulting brews cycling through this bar just south of the Jean-Talon Market. 6631 boulevard St-Laurent; www.vicesetversa.com