Baby Back Ribs on Maple Planks

I only have a propane BBQ - and I think that is what the majority of us use.  This is a recipe from Food and Drink 2011 that I loved. You can switch the maple planks for an apple wood or your choice.  Soak the wood in water for at least a couple of hours, overnight is better.  Use two 12 x 6 inch planks.  Serve with corn on the cob!

Barbecue Sauce
1 cup apple juice
3/4 cup ketchup
3 tbsp cider vinegar
2 tsp light soy sauce
1 tsp Worcestershire sauce
1 tsp molasses
1/2 tsp chili powder
1/2 tsp garlic, minced
1/4 tsp black pepper

Rub
1 tsp paprika
1 tsp chili powder
1 tsp thyme
1 tbsp garlic powder
1 tsp brown sugar
1 tsp dry mustard
1 tsp kosher salt
1 tsp black pepper

2 full slabs baby back ribs

1. To make sauce, combine all ingredients in a medium saucepan.  Cook over high heat until reduced by half, or about 1 cup.
2. To make rub, add all ingredients to a small bowl and stir to combine.
3. Peel the thin membrane off the back of the ribs (this helps the meat cook more evenly and absorb more flavour while cooking).  Using your fingertips, rub the meat liberally with the rub, wrap in plastic wrap and refrigerate for 1 to 3 hours.
4. Meanwhile soak planks in water for 1 to 2 hours.
5. Ignite grill, turn to high and preheat for 10 minutes.  Turn 1 side off leaving the other on, and place planks on the side that has been turned off.  Close lid and wait for the planks to begin to crackle and smoke, between 3 to 5 minutes.  Turn planks over and place a rack of ribs on each plank, reduce heat to low, and close lid.  Maintain a temperature range between 275 to 300 F and cook for 3 hours.
6. Brush both sides of ribs liberally with barbecue sauce and continue cooking with the lid closed for an additional hour.  Ribs are done when the sauce has become sticky and the meat separates easily from the bones.