“Have a ball!”

It started off as an April Fool’s Day joke (video), but now, Denver, Colorado’s Wynkoop Brewing Company has made a batch of Rocky Mountain Oyster Stout, a beer made with real bull testicles (which they describe as the “ballsiest beer ever”). It will be made available at Wynkoop Brewing Company and at their table at the Great American Beer Festival in Denver from October 11-13, 2012.

The beer is made with Colorado-grown base malts, roasted barley, seven specialty malts (including special B and smoked malt) and Styrian Goldings hops. The beer gets a small dose of sea salt, too. “It gives the beer an extra layer of Rocky Mountain oyster flavor,” Brown notes, “and additional texture.”

The 8-barrel batch also included 25 pounds of bull testicles that were sliced by hand and then roasted (by Wynkoop sous chef Andrew Langlo) before being added to the beer’s mash.

So how does it taste? Rocky Mountain Oyster Stout is an assertive foreign-style stout, slightly viscous, with a deep brown color. It has equally deep flavors of chocolate syrup, Kahlua, and espresso, along with a palpable level of alcohol and a savory umami-like note.It finishes dry and roasted with a fast-fading hop bite.

The beer is 7% ABV and has 3 BPBs. That’s balls per barrel.