Coffee and Chocolate
As intertwined as morning and mocha, coffee and chocolate are finding their way into beer. However, dealing with the head-killing oils is a challenge when using coffee or chocolate. Not surprisingly, they mostly appear in porters and stouts, where they intensify roasted malt flavor and head doesn't matter.
Why add vanilla to a chocolate beer?
Vanillin, the active molecule in vanilla, is a large contributor to the “chocolate” flavor profile. A vanilla bean or extract added to the fermenter will boost the perception of chocolate.