Coors Light measures in at 4.2% alcohol by volume. That’s about standard when it comes to standard beers, from the ales poured a English pubs to the lagers that are mass-produced around the world. It’s a little on the low end for craft beers, though. New Belgium Brewing’s Fat Tire, for instance comes in at 5.2% ABV, while Odell Brewing’s IPA is 7%.
But none of them compares to the behemoths that Denver’s River North Brewery will showcase at its 12th anniversary party this Saturday. They’ll be running at 22.1%, 23.5% and 24.1% — and the latter two are most likely the highest-alcohol beers ever made in Colorado.
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Boosting the alcohol content has been an annual tradition, as well as a scientific challenge, for the past few years for River North Brewery owner Matt Hess and head brewer Matt Malloy.
“It’s always fun to do this,” Hess said, but “it’s not about the alcohol. It’s about getting the intensity of flavors that you can savor like a cocktail.”
River North has always specialized in making higher-ABV, barrel-aged stouts, barleywines and Belgian-style ales — something that delights the brewery’s fans — but they began to reach even further about three years ago in the runup to the company’s 10th anniversary. That year, River North created a 22% ABV beer called Anniversary 10 Stout. Last year, it followed up with its 23.2% Anniversary 11. This year, the anniversary ale came in at 22.1% ABV.
It is an extremely complex blend of other stouts that were aged multiple times in a huge variety of wooden barrels that once held Colorado bourbon, Kentucky bourbon, honey barrel-finished whiskey, tequila barrel-finished whiskey, sherry barrel-finished whiskey, Colorado rye whiskey, and Colorado single malt whiskey. For the two higher ABV beers, they pulled out a couple of barrels — from local distilleries Stranahan’s Whiskey and Spirit Hound — to age separately.
To make the beers, Hess, Malloy and fellow brewer Heath McNeil, have to be careful about when and how they add sugars — like dextrose and Belgian candi sugar– which yeast turns into alcohol. Do things too fast and they could shock the yeast, which would result in less fermentation. Then there’s the care that goes into the aging process when both ethanol and water evaporate over the months and years.
To accurately measure the alcohol content, Malloy built a lab-grade distillation apparatus — to the specifications of the American Society of Brewing Chemists — because traditional methods of measuring alcohol content in beer wouldn’t have worked. He also sourced the proper equipment from a specialized lab glassware manufacturer in Kentucky.
River North brews about four beers per year above 20%, but it’s not the only brewery that does so. Burns Family Artisan Ales, which has two taprooms in Denver, also makes beers that flirt with that number, and has even collaborated with River North. Upslope Brewing in Boulder has also produced a cordial-like beer called Grand Reserve that clocked in at around 20%. And back in 2003, the now-defunct Grand Lake Brewing made a beer-like concoction called Holy Grail that had about the same alcohol content.
But no one has so far cracked the 23% mark, let alone 24%, as far as Hess (along with independent research by The Denver Post) can tell.
By comparison, wine typically has 12 to 13% ABV. And that is why Hess ordered a special set of glassware for the 12th anniversary party that has with a 2-oz fill line. Customers will be limited to 2-oz per pour rather than a 3-oz pour, which is how other high-ABV beers are served.
“We’ve never done anything as crazy as this,” Hess said. “But [our customers] appreciate the beers we make that you can sip and savor throughout the year.”
River North Brewery’s 12th anniversary party takes place at both of the company’s locations, 3400 Blake St. and 6021 Washington St., on Saturday, Feb. 17, from 1 to 9 p.m. Reservations aren’t necessary, but you can RSVP on eventbrite for a discount on a taster of a hazy IPA.
