Spatchcocking a 30 lb turkey
So I have a turkey that a friend raised that got out of control. It is at least 30 lbs!!! I have decided to spatchcock with the stuffing underneath the breast. I am hoping that I can get an idea of how many minutes per pound to plan the rest of the meal around. I will be using two meat thermometers also.
I will be cutting the legs off and taking the backbone out without breaking the breastbone.
I would not cook the dressing underneath a bird of that size: you will lose most of the benefits of butterflying and it will take longer to cook. You will want air to circulate under that thing. (I've done this with a bird of about 18 lbs and the dressing prolongs cooking unduly, sad to say).
Frankly, I would just joint the thing, cooking the breast (in halves) and the other pieces in smaller joints. That way, you can remove each piece when done et cet.
re: Karl S
You should flatten the breastbone if you can. You can put a tray or mound of stuffing in your roasting pan, then a large cookie cooling rack across the top of the roasting pan, sitting on its rim.
Put the bird on that. You will still get air circulation underneath the bird, but plenty of drippings to flavor and baste the stuffing.
Using a meat thermometer is really a must since even two birds of identical weight can be proportioned differently enough to significantly affect cooking time. If you don't have one you'll have to rely on the browning of the skin and how wiggly the leg joints are.
I am going to guess 3-4 hrs (probably closer to 3 or even a bit under if there were no dressing underneath). Depends on the cooking temperature (the larger the joint of flesh, the more moderate the temperature you should use), how much air circulates under it, and how cold the deepest part of the flesh is when you put it in the oven (the colder it is, the more carryover cooking occurs after you remove it from the oven). Better to err on the early side; turkey can be kept warm for a while, and it takes quite a long time for it to cool down to a comfortable carving temperature without much loss of juice.
Thank you Karl and Greygarious for your prompt replies, but I still have my original question... with the understanding that I will be using 2 thermometers to ensure that everything is nicely done, how long should I plan as an approximate time for the turkey. Considering I was looking at 8.5 hours without removing the backbone and thighs, I am still planning on getting up early but I don't want to guess that dinner will be at 3 and have the turkey actually done at 1, or 6. If you know of a rough way to estimate it would be greatly appreciated!