1 12-ounce bottle dark beer, like a stout, porter, or Scotch ale
2 tablespoons maple syrup
2 teaspoons stone-ground mustard
1 bay leaf
8 precooked bratwurst sausages
8 hot dog buns or hoagie rolls
Red Pepper Relish, optional to serve
Whisk the beer, maple syrup, mustard, and bay leaf together in a bowl, then pour into a gallon-sized zip-top bag. Add the brats and marinate overnight or up to 24 hours.
Preheat a gas or charcoal grill to medium direct heat (about 350°F to 400°F).
Toast the buns or rolls on the grill, if desired, then remove and set aside on a platter.
Remove the brats from the marinade and place on the grill. Cook, flipping and turning as needed, for 7 to 10 minutes, until the skins are browned and the internal temperature registers 140°F.
Nestle a brat into each bun and top with red pepper relish or your favorite condiments.