3-2-1 Ribs: The Great Lie
Season and rub before cooking for 3 hours, then wrap for 2 hours, then unwrap and glazing with sauce before cooking for a final hour. That is the simplicity of 3-2-1 ribs.
It is also ridiculous. Cooking what is essentially bones for 6 hours is overkill. If you want to follow the technique but still have some moisture and bite in your ribs then I recommend using half hours instead - so 3 x 30 mins, 2 x 30 mins, and 1 x 30 mins - or to put it another way 90 mins, 60 mins, and 30 mins or 90-60-30.
It is likely you won't even need that last half hour as glazing usually takes less than 15 mins.
I hear you protest - you are saying that 3-2-1 is perfect for big fat American pigs. I don't think so and neither does our good friend and famous American BBQ Pitmaster Harry Soo.
Here are some pictures I took recently of a 90-60-30 ribs cook using Iberico pork over cherry wood.