*Simmering the bones, meat, and skin breaks down the collagen, releasing it into the liquid. This turns into gelatin, and is completely natural (it's not fat!). The more you reduce the liquid by simmering the turkey carcass, the thicker the stock will become. At cold or low temperatures it becomes very thick, and has a jelly-like consistency. At higher temperatures it 'melts' to become a rich flavor-packed liquid again. If you are making soup, feel free to add more water to thin it out if you prefer, but taste as you go, so you don't lose too much of the flavor.
If you don't want to make soup, another great option is to freeze the broth into ice cube trays (small plastic bags or containers). Then you can pop a few into whatever dish you need to enhance with a rich meaty flavor.