Transfer pan juices to a 2-quart glass measure, then skim fat, reserving 3 tablespoons of it. Add enough turkey stock to pan juices to total 4 1/2 cups. Straddle roasting pan across 2 burners, then add wine and deglaze pan by boiling over moderately high heat, stirring and scraping up brown bits, until wine is reduced by half, about 5 minutes. Add stock mixture and jam and boil, stirring, until jam is melted. Pour through fine-mesh sieve into glass measure.
Whisk together reserved fat and flour in a large heavy saucepan (it will be about the thickness of peanut butter) and cook roux over moderately low heat, stirring, 3 minutes. Add hot stock mixture in a fast stream, whisking constantly to prevent lumps, and simmer, whisking occasionally, until thickened, about 5 minutes. Stir in turkey juices accumulated on platter and simmer 1 minute. Season with salt and pepper.