Firestone Walker Brewing Co.’s Velvet Merkin has returned, but with a twist.

The Pasa, Robles, Calif.-based brewery will once again be releasing Velvet Merkin, an 8.5 percent ABV oatmeal stout brewed with fuggle hops as well as maris otter, 2-row pale, roast barley, English dark caramel, medium caramel and carafe malt malts before being aged in bourbon barrels from Elijah Craig and Old Fitzgerald. According to a press release, for the first time the brewery added a “barrel-aged lot of an experimental milk stout version of Velvet Merlin.”

Firestone Walker Velvet Merlin

“We didn’t really change Velvet Merkin, we just gave it a tweak by incorporating this small amount of milk stout to fill out the mouthfeel,” said Matt Brynildson, brewmaster at Firestone Walker, in a press release. “You might barely notice it, but it makes a difference. We could have kept this detail to ourselves, but we didn’t want to be accused of a cover up.”

Velvet Merkin originally debuted in 2008, but was first bottled as part of Firestone Walker’s Vintage Series in 2013. Only 3,500 cases will be released.

The 2015 version of Velvet Merkin will be packaged in 22-ounce bottles ($16.99) and officially be released at the brewery on Sept. 12 before being sent to “select markets” in Firestone Walker’s distribution footprint.