Remove the membrane from the back of the ribs. Coat with mustard and rub.
Smoke at 225°F for 3 hours, spritzing with apple juice in the last hour.
Lay out foil with brown sugar, butter pats, and honey; place ribs meat-side down and wrap tightly. Smoke 2 hours.
Unwrap, brush with BBQ sauce, and smoke 1 more hour to set the glaze.
Rest 10 minutes, then slice between the bones.
Baby backs vs spare ribs
This timing is for spare ribs. For baby backs, use 2-2-1 — they're smaller and cook faster. Done ribs bend and crack on the surface when you pick up the rack.
FAQ
Do I have to wrap?
No — unwrapped ribs have more bark and bite. The 3-2-1 wrap makes them more tender and fall-off-the-bone, which most people prefer.