Mix 1/4 cup hot water with the instant coffee and stir to dissolve. Once, dissolved, combine with the plum sauce, orange juice, chipotle sauce and brown sugar in a small saucepan over medium heat. Bring the sauce to a boil and reduce the heat. Simmer until slightly thickened, about 5 minutes. Season with salt and pepper.
Coat both sides of the ribs with the sauce, saving 2/3 cup for basting. Arrange the ribs, meaty-side up, in 1 layer in a foil-lined baking sheet. Cover the pan tightly with foil and bake the ribs 1 hour. Remove the foil (from the top), baste with the remaining BBQ sauce and bake the ribs 1 hour more.
Allow the cooked ribs to rest for 10 to 15 minutes before slicing and serving.