Combine all the rub ingredients in a bowl and mix together. Rub the rub all over the ribs.
Let the ribs sit in the fridge for 4 hours.
Pour the apple cider vinegar and liquid smoke in the instant pot and add the trivet. Place the ribs on the trivet and seal the instant pot.
Pressure cook on high for 30 minutes with the apple cider vinegar.
Let the pressure release naturally for 20 minutes, then release any remaining pressure with the quick release.
Heat grill to 500F degrees or the broiler on high. Brush the ribs with BBQ sauce.
Grill ribs for 3-5 minutes per side (or broil), until the sauce has caramelized.
Remove and let rest for 5 minutes. Slice and serve with extra BBQ sauce.
Notes
Be sure to remove the membrane from the pork ribs before putting the rub on.
I recommend leaving the rub on the ribs for 4 hours. However, if you're strapped for time, you can cook the ribs as soon as the rub has been applied.
Let the pressure release naturally for 20 minutes before hitting the quick release - this helps to keep the ribs from getting tough.
Finishing them on the grill or under the broiler is optional. You can eat them straight out of the Instant Pot if desired, but you will miss out on that beautiful caramelization.
I HIGHLY recommend making this Homemade BBQ Sauce - it's so much better than store bought.
You can also use this same recipe to make baby back ribs. They cook for the same amount of time.
You can cook these ribs straight from frozen as well - just add 10 minutes to the pressure cooking time.