Remove ribs from packaging and pat dry with paper towels. Optional: slide a knife under the back membrane and peel it away. Mix dry rub spices — garlic powder, paprika, cayenne, onion powder, black pepper, and mustard powder — then coat ribs liberally on all sides. Light 6–8 pieces of lump charcoal in a chimney until fully burned, then transfer to the firebox. Place a metal water pan filled with apple juice, water, or fruit juice in the cooking chamber near the firebox.

Preheat smoker to 121°C; open vents at both ends for airflow. Place seasoned ribs on the grate and add wood chips (applewood, cherry, or hickory) — aim for thin blue smoke, not thick gray. Smoke 3–5 hours (baby backs cook faster than spareribs). Spray ribs with water every 30–60 minutes to keep the surface moist. Maintain 121°C by adding charcoal as needed. Around 77°C internal temp, remove ribs, brush with barbecue sauce if using, and wrap tightly in foil. Return to smoker for 30–60 more minutes. Done when meat pulls easily from the bone and hits 93°C internal.

Remove ribs from smoker and carefully unwrap foil — watch for steam. Rest off heat for at least 15 minutes so juices reabsorb. Slice between bones and serve with barbecue sauce on the side or brushed on. Avoid cooking above 149°C, using thick gray smoke, or skipping the rest — all lead to dry ribs.