When the leaves change color, beer store shelves turn orange to match. It's pumpkin beer season, and the trap is set. Each year, we can't resist plucking a bottle or two, but like a bowl of candy corn, their festive hue belies their taste: too sweet, too sour and sodden with perfume-y spice.

It doesn't have to be this way. The best pumpkin beers are the most unexpected. Far from pie-in-a-bottle, they blend in maple syrup, dark chocolate and the vanilla smoothness of oak barrels—dressing...