Merkl attributes part of the success to brewing an easily accessible style with a lower alcohol percentage (4.5 percent alcohol by volume) than is typically found in a craft beer.
"It's a Pale Ale, so it's not like you're trying something super crazy," he said. "We wanted something people could drink before, during and after a game, and have more than one."
The buzz surrounding the beer has helped Hilliard's increase distribution and win over some football fans as a result.
"It introduces people to craft beer and other craft drinkers to our brand," said Hilliard. "The number of stores that have picked it up has been far and wide. Hopefully, it opens people up to trying something new."
In keeping with its name, Hilliard's sells the beer, in what else, 12-packs of 16-ounce tallboy cans for about $22 to $23 per pack.
Hilliard's is no stranger to marketing success, having brewed a collaboration beer with Seattle-based Redhook Brewing that is made with hemp to celebrate Washington's new marijuana laws.
(Read more: New marijuana laws get brewers buzzing)
While sales of 12th Can have been steady throughout the season, Hilliard's said they've picked as the excitement over the Seahawks' playoff run increases.
But the playoffs have put the brewery in an interesting position.
"You're trying to hit the sweet spot and you don't want to run out of beer before the playoffs, but you don't want to have a bunch of beer left over at the end either," said Hilliard. "There's not really a perfect way to do it, but make some educated guesses. We're just hoping we made enough of it."
—By CNBC's Tom Rotunno. Follow him on Twitter