Prepare Smoker for indirect cooking at 275 degrees F (140 degrees C).
Remove the St. Louis Spare Ribs (2 rack) from packaging, trim excess fat and remove membrane from bone side.
Combine Kosher Salt (1/4 cup) and Freshly Ground Black Pepper (1/2 cup) in a bowl and pour into a shaker bottle. Season ribs liberally on both sides with salt and pepper mixture.
Place ribs on smoker and add pecan wood chunks to the fire for smoke. Cook for 2 1/2 hours.
Mix Water (1 cup) and Apple Cider Vinegar (1/2 cup) in a spray bottle. Spritz ribs every 45 minutes.
After 2 1/2 hours remove ribs from smoker, spritz with vinegar mixture and wrap in aluminum foil.
Return ribs to smoker and continue to cook for approximately 2 hours. Check ribs for doneness after 1 hour and every 15 minutes after. Once desired tenderness is reached pull off smoker.
Rest ribs for 15 minutes and serve.