In a saucepan, simmer the beer, chicken broth and bratwurst for 10 minutes. Reserve the bratwurst and cooking liquid separately.
Meanwhile, in a large skillet, cook the bacon over medium heat for 6 minutes. Using a slotted spoon, transfer to a plate. Add the onions to the skillet and cook over medium-high heat until softened. Add the reserved cooking liquid, bring to a boil and cook until most of the liquid has evaporated, about 8 minutes. Add the sauerkraut, carrots, bacon and bratwurst and cook, covered, until heated through. Stir in the apples.