1Cut the bacon crosswise into 1/4 inch pieces. Melt the butter in a large Dutch oven over medium heat; add bacon, and cook, stirring often, 8 minutes or until crisp. Drain the bacon on paper towels, reserving drippings in skillet.
2Saute onion in hot drippings 3 minutes or until the onion is tender. Stir in bacon, ale, and next 3 ingredients; cook 3 minutes or until the mixture is reduced by one-fourth.
3Add the collards, in batches, and cook, stirring occasionally, 5 minutes or until wilted. Reduce heat to medium-low; cover and cook 1 hour or to desired degree of doneness. Stir in vinegar, salt, and pepper.