Zwanze 2015, or Wild Brussels Stout, was brewed in March of 2013 and was originally a candidate to be served for the Zwanze Day celebration in 2014.

Zwanze 2015 is Cantillon’s interpretation of a spontaneously fermented stout. Aged for 28 months, Wild Brussels Stout is a blend of Cognac, red wine, and Lambic barrels. The beer coming from Cognac barrels brings a warming alcohol character, while the beer coming from the red wine barrels has a vinous, fruity presence. The fruitiness and roast give this "wild" stout a nutty character reminiscent of wine from Madeira or Banyuls.