Put the chopped turkey carcass in an 8-quart stockpot, and add cold water to cover, leaving 2 inches of space at the top of the pot. Bring to a boil over medium-high heat; then reduce the heat so that the liquid simmers steadily. Using a large spoon or soup skimmer, skim off the brown foam that rises to the top. After 5 minutes or so, the foam will become white, and no more skimming will be necessary.

Add all the remaining ingredients. Partially cover the pot and adjust the heat so that the stock barely simmers. Cook the stock for at least 2 but preferably 4 hours, adding water, if necessary, to keep the bones covered.

Using a slotted spoon, transfer the bones, meat, and vegetables to a large, fine-mesh strainer set over a large bowl to catch all the juices. Discard the solids. Pour the stock through the strainer into the large bowl. Let cool. (To cool the stock quickly, set the bowl in a larger one filled with ice water, or fill a sink with about 2 inches of ice water.) Stir the stock, occasionally, to help cool it down. Cover and refrigerate overnight.

The next day, lift and scrape the congealed fat from the surface using a large spoon. Discard the fat. Store the stock, covered, in the refrigerator for up to 3 days. To keep longer, transfer to a freezer container or several small containers, allowing 1 inch of headspace, and freeze for up to 6 months.

VARIATION: CHICKEN STOCK

Follow the recipe for Turkey Stock, substituting 3 quarts (about 3 pounds) chicken parts for the turkey carcass.