Whisk together the spray mixture ingredients and place in a spray bottle.
Combine the chili powder, thyme, onion powder, and seasoned salt in a bowl.
Rub the mustard on all sides of the short ribs. Sprinkle the spice mixture all over the short ribs.
*Be sure that your hopper is full of pellets before you begin so that you don’t run out during the long cooking process.Place short ribs on the preheated smoker and smoke for 3 hours, opening smoker and misting the meat every hour.
Remove from smoker, spray one more time, then wrap in foil. Place back on smoker for 30 minutes or up to an hour, depending on how meaty your ribs are.
Remove from smoker and let rest, wrapped in foil, for 30 minutes.
Notes
Try to choose well-marbled short ribs that are fairly uniform in size so they cook evenly.
For fall-apart tender short ribs, aim for an internal temperature of around 190 – 205F read on an instant read thermometer inserted into the thickest part of the rib.
Store cooled leftovers in an air-tight container kept in the refrigerator for up to 4 days.
Serve smoked beef short ribs with a side of mashed potatoes, rice, roasted carrots, asparagus, mushrooms, broccoli, or green beans. These ribs also pair well with coleslaw, mac and cheese, pasta salad, potato salad, and corn on the cob.