Sprinkle the salt, pepper and cayenne all over the cow head.Completely wrap the cow head in several layers of banana leaves, securing it with kitchen twine.In a banana-leaf-lined hotel pan, pour two bottles of beer.Set the banana-leaf-wrapped cow head into the pan, and fold over pan-lining leaves.Cover cow head and bottom pan with another hotel pan. Secure tight with kitchen twine.Smoke at 250°F for 24 hours, remove meat from head (will have to peel the skin off of the tongue), pull apart and make tacos!