Pre-heat oven to 120℃/250℉
Line your oven trays with foil. I can usually fit 2 racks of ribs comfortably on one tray, but depending on the size of yours, you may need more trays.
Remove the membrane from all 4 pork ribs (see video in note 3)
Now if you are using the liquid smoke, add it to a small bowl, along with the water. Now evenly brush this mixture over the ribs until all gone.
Add all spice rub ingredients into a bowl, mix well. Now sprinkle and rub all of the spices evenly over all 4 sets of ribs making sure to get into every nook and cranny.
Pour 1/2 a cup of water into the bottom of each baking tray, this will help the ribs steam. Cover ribs with foil and seal tight, so no steam will escape. You may need more than 1 piece of foil to accomplish this. Place ribs in oven and cook undisturbed (no peeking) for 3½ hours.
Once 3½ hours are up remove ribs from oven and remove foil covering. At this stage the bones should be peeking out from the meat and the bones should be wiggly if you try to wiggle them. If this is not the case, return to oven until this happens, it can take up to as much as 5-6 hours if your ribs are huge and meaty.
Baste your ribs with the BBQ sauce, be generous, both sides. Return to oven uncovered and cook for 20 minutes.
Remove ribs from oven. Baste again with BBQ sauce, and serve.