Add the juniper berries, bay leaves (broken if needed) and caraway to a small sachet or metal tea ball. Set aside for later. In a large, enameled cast-iron casserole pan, cook the bacon until fat is rendered and crispy. Remove bacon, transferring to a paper towel lined plate. You will want about 3 tablespoons of bacon grease left in the pan. When cool, chop into small pieces, reserve for later. Add the onion to the pan, cover partially and cook over medium low heat, stirring occasionally, until very soft, about 20 minutes. Increase the heat to medium high. Add the wine, apple, spice blend, sugar, kosher salt and pepper, and boil for 3 minutes. Add the broth (or water) and the sauerkraut. Reduce the heat to low, cover and cook until the apple is very tender, about 45 minutes. Spoon the sauerkraut onto a large serving platter and arrange with sausages (not covered in this recipe) on top. Sprinkle the reserved bacon over the sausages and serve with mustard (preferably a grainy German style).