Prepare a charcoal grill using the snake method: Stack the unlit charcoals around the perimeter of the grill, about halfway, then light the first few at one end so the snake begins to burn slowly. (This results in a controlled 325 to 350 degrees F heat; see Cook's Note.) Fill a metal loaf pan with about 1 cup water and place it next to the coals for additional moisture.
Season the ribs liberally with salt and pepper.
Combine the beer, sugar, soy sauce, ketchup, mustard, vinegar, ginger, crushed red pepper flakes, garlic, a small pinch of salt and about 1/2 teaspoon pepper in a medium saucepan and whisk until smooth. Bring to a simmer over direct heat and cook until reduced by a third, about 30 minutes.
Place the ribs bone-side down on the grill over indirect heat. Close the grill and cook, brushing the ribs with the glaze every 30 minutes to an hour, until an instant-read thermometer registers 200 degrees F, 3 to 3.5 hours. (Make sure to keep the temperature of the grill between 275 to 350 degrees F.)
Take the ribs off the grill, wrap in aluminum foil and let rest 10 to 15 minutes. Bring the remaining glaze back to a simmer over direct heat for several minutes. Garnish the ribs with the cilantro and serve with the remaining glaze on the side.
(Alternatively, you can bake the ribs on a rimmed baking sheet in a 300 degrees F oven for 3 to 3.5 hours.)
If the temperature gets too hot, close the airflow of the grill; if the temperature cools down, open the airflow of the grill.