I'm sure fresh is best, but... true story --
last year (around September?) we had a frozen turkey in the freezer that I knew was getting out to the limits of edibility...
so, I pulled it out and thawed it slowly then pushed some butter up under the skin, then roasted the thing breast-side down for about half of the total time; and then flipped it over and cooked it for the rest of the time.l
Best turkey I ever cooked!!
