Brown Turkey Stock

Heat oven to 450 °F with rack in lower third. Spread turkey parts and vegetables out in a large roasting pan and roast, turning over once, until deep golden, 45 minutes to 1 hour. Transfer turkey and vegetables with a slotted spoon to a 5- to 6-quart heavy pot. Position roasting pan across 2 burners, then add 2 cups water and deglaze pan by boiling over high heat, stirring and scraping up brown bits, 1 minute. Add pan juices to pot with remaining water, bay leaf, peppercorns, and 3/4 teaspoon salt and bring to a boil, skimming froth. Reduce heat and cook at a slow simmer, checking occasionally and skimming any froth, 2 hours. Strain stock through a fine-mesh sieve into a bowl, discarding solids. Measure stock: If there is more than 6 cups, boil in cleaned pot to reduce. If there is less, add water to make it 6 cups. If using stock now, let stand until fat rises to top, 1 to 2 minutes, then skim off and discard fat. If not using now, cool completely, uncovered, then chill, covered, before removing fat.