In a large pot, combine the lager, baby back ribs, carrots, celery and onion and bring to a boil. Simmer over low heat, turning the ribs a few times, until the ribs are tender, about 1 1/2 hours. Transfer the ribs to a work surface and let cool. Cut in between the ribs at 2-rib intervals.
In a large saucepan, heat the bacon fat. Add the onion and cook over moderate heat, stirring occasionally, until softened, about 10 minutes. Add the garlic and ginger and cook for 5 minutes longer. Whisk in the orange juice, ketchup, vinegar, brown sugar, coffee, sambal oelek, molasses, tamarind concentrate, mustard and Worcestershire sauce and bring to a boil. Simmer over low heat, stirring occasionally, until thickened, about 45 minutes. Season with salt and pepper. Working in batches, puree the sauce in a food processor.
Light a grill. Brush the ribs with oil. Grill over moderate heat, turning, until lightly browned, about 5 minutes. Brush the ribs with the sauce and grill, turning and brushing with more sauce, until richly glazed and browned, about 2 minutes longer. Serve the ribs with extra sauce for dipping.