You should sign up for Jeff's monthly newsletter. Lots of great recipes and cooking suggestions. His newsletter I received this morning goes to the very heart of your question:
Smoking a Turkey Larger than 14 lbs
As most of you know, I do not recommend smoking a turkey that is larger than 12 lbs.. 14 lbs is pushing it. This is due to the fact that the larger turkey takes too much time to reach a safe temperature at the low temperature. It is risky at best and in my opinion, is raising the chances that your family and guests could get a food borne illness.
To make it safe, keep the turkey on the small side (12 lbs is about right) and if you need more turkey, just smoke multiple turkeys figuring on about 2 lbs of raw weight per person.
I just usually figure a 12 lb turkey for every 6 people and it gives me plenty of turkey with a few leftovers.
So you’ve already purchased a big ol’ 22 pounder so what now? Well, you really only have a couple of options for smoking it safely.
Option 1: Smoke then Bake
Prepare the turkey as you desire, smoke it for about 2 hours at 225-240°F in the smoker then finish it in the oven at 325°F until it reaches 165°F in the thickest part of the breast and thigh. I expect this to take an additional 2.5 to 3 hours in the oven however, use the temperature as your guide rather than the time.
Option 2: Spatchcock (Butterfly) the Turkey
Using kitchen shears, cut along both sides of the backbone of the turkey removing the backbone completely from the turkey.
You will then be able to lay the turkey open (the breastbone is the hinge).
Prepare the turkey as you normally would with seasoning under the skin, on the skin, etc.
Smoke the turkey with the skin side up until it reaches reaches 165°F in the thickest part of the breast and thigh.
By laying the turkey open in this way, it will cook must faster and more evenly and that's a good thing with larger turkeys in the lower heat of the smoker.
Should I Stuff the Smoked Turkey?
ONLY after it’s done. Stuffing prevents the heat from flowing into the cavity as it needs to and causes it to take longer to cook, something you do not need at low smoking temperatures.
If you want the bird to be stuffed for presentation, make the stuffing in a separate container in the oven and stuff it into the turkey after the turkey is done cooking and just prior to placing it on the table.
It is fine to place a few pieces of onion, apple, butter,etc. in the cavity as long as the heat flow is not impeded in any way.
