Mammoth beef ribs are smoked low and slow with a simple Dijon-and-beef-rub crust, then spritzed with a tangy vinegar-hot sauce to build a dark, savory bark. The result is ultra-juicy, fall-off-the-bone beef with deep smoke and a subtle peppery heat.
Preheat your smoker to 250°F for indirect cooking using a hardwood like oak or hickory.
Slather the ribs all over with Dijon mustard with horseradish, then season liberally on all sides with Beef Rub (or an equal-parts mix of salt, pepper, and garlic powder).
Place the ribs on the smoker and insert a meat probe into the thickest part of the meat without touching bone. Close the lid and smoke for 3 hours (target internal temperature 203°F).
Combine the white vinegar and hot sauce in a food-safe spray bottle. After the initial 3 hours, spritz the ribs every 45–60 minutes and continue smoking until the ribs reach 203°F internal temperature (typically 8–10 hours total).
Remove the ribs, wrap in foil, butcher paper, or unwaxed parchment, and rest in an insulated cooler for at least 1 hour before slicing and serving.