I roast a turkey in a bag. The skin color is beautiful. But why doesn't the skin stick to the turkey when I carve it.
When it's in a bag, the steam produced during roasting is trapped. A layer of steam occurs between the skin and the meat, separating the skin from the meat.
The same process happens when cooking without a bag, just more slowly, as the steam fills the entire oven - and then some of it escapes through vents or out the door seal.
Turkeys release a surprisingly large amount of liquid when cooked, compared to other poultry, so the skin separation is more pronounced than in chickens.