Remove the ribs from the packaging, blot dry, and place them onto a lined baking sheet. Place it into the refrigerator for 1-4 hours to form a pellicle on the surface.
Next, remove the ribs from the fridge, and let them stand at room temp for 15-20 minutes.
Preheat your pellet grill or smoker to 225 degrees F.
Trim off any excess knobs of fat or meat from the top of the ribs.
Flip the baby back ribs over so that the bone side is facing upward. Make a slit in the silver skin with a sharp knife. Next, grab ahold of the cut piece with a folded paper towel. Pull up and gently pull off the membrane.
Flip the rack of baby backs over, and coat the meat section with yellow mustard. Apply the BBQ rub evenly to the ribs.
Place the ribs bone-side down) on the pellet grill, close the lid, and let it go for 1 1/2 hours.
After this time, you'll notice that the ribs have formed a deep brown bark on the surface. You might also notice some dry patches.
Fill your food-safe spray bottle with room-temperature apple juice (or cider vinegar plus water). Mist the ribs with the mixture.
Close the lid and let the ribs cook until they reach an internal temperature of 160 degrees F.
Remove the ribs and place them onto a large sheet of butcher paper. Gently wrap them up, and place them back on the grill. If you want to skip this step, you can.
Once the ribs reach an internal temperature of 185 degrees, unwrap the baby back ribs. Place them back on the grill and brush with BBQ sauce. Let them cook for an additional 30 minutes.
Ribs are done once they reach an internal temperature of 195-200 degrees F.
Remove ribs from the heat and place them onto a clean cutting board. Let them rest for 15 minutes.
Slice into individual ribs and serve with extra BBQ sauce on the side.