Preparation Place turkey neck, heart and gizzard in large pot. Add 8 cups cold water and 2 celery stalks; bring to boil. Reduce heat to medium-low and simmer 1 hour. Strain into large measuring cup. Return turkey stock to pot; simmer until reduced to 4 cups, about 30 minutes. (Can be prepared 1 day ahead. Cover; chill.) Position rack in bottom third of oven and preheat to 350°F. Rinse turkey inside and out; pat dry. Remove excess fat from neck and main cavities. Place turkey on rack set in large roasting pan. Place onion, apple and remaining 2 celery stalks in main cavity. Rub outside of turkey with bacon drippings; sprinkle with salt and pepper. Loosely tie legs together to hold shape. Cover breast portion of turkey with sheet of heavy-duty foil. Pour turkey stock into pan around turkey. Roast turkey 1 1/2 hours. Remove foil from over breast. Baste turkey with pan juices. Continue to roast turkey until thermometer inserted into thickest part of thigh registers 180°F, basting occasionally with pan juices, about 1 1/4 hours longer. Transfer turkey to platter; let stand at least 20 minutes. Pour juices from roasting pan into large glass measuring cup. Spoon off fat, reserving 2 tablespoons. If necessary, add enough chicken broth to degreased pan juices to measure 2 1/2 cups. Heat 2 tablespoons turkey fat in heavy medium saucepan over medium-high heat. Add flour; whisk until beginning to color, about 2 minutes. Gradually whisk in pan juices and any collected juices from platter holding turkey. Boil gravy until thickened enough to coat spoon, whisking often, about 8 minutes. Season with salt and pepper. Serve turkey with gravy.
Preparation Place turkey neck, heart and gizzard in large pot. Add 8 cups cold water and 2 celery stalks; bring to boil. Reduce heat to medium-low and simmer 1 hour. Strain into large measuring cup. Return turkey stock to pot; simmer until reduced to 4 cups, about 30 minutes. (Can be prepared 1 day ahead. Cover; chill.) Position rack in bottom third of oven and preheat to 350°F. Rinse turkey inside and out; pat dry. Remove excess fat from neck and main cavities. Place turkey on rack set in large roasting pan. Place onion, apple and remaining 2 celery stalks in main cavity. Rub outside of turkey with bacon drippings; sprinkle with salt and pepper. Loosely tie legs together to hold shape. Cover breast portion of turkey with sheet of heavy-duty foil. Pour turkey stock into pan around turkey. Roast turkey 1 1/2 hours. Remove foil from over breast. Baste turkey with pan juices. Continue to roast turkey until thermometer inserted into thickest part of thigh registers 180°F, basting occasionally with pan juices, about 1 1/4 hours longer. Transfer turkey to platter; let stand at least 20 minutes. Pour juices from roasting pan into large glass measuring cup. Spoon off fat, reserving 2 tablespoons. If necessary, add enough chicken broth to degreased pan juices to measure 2 1/2 cups. Heat 2 tablespoons turkey fat in heavy medium saucepan over medium-high heat. Add flour; whisk until beginning to color, about 2 minutes. Gradually whisk in pan juices and any collected juices from platter holding turkey. Boil gravy until thickened enough to coat spoon, whisking often, about 8 minutes. Season with salt and pepper. Serve turkey with gravy.