6 lbs. chicken carcasses, backs, legs or wings
3 large celery ribs, cut into 2 inch lengths
2 large carrots, cut into 2 inch lengths
2 unpeeled medium onions
3 quarts water

Combine all of the ingredients in a stockpot and bring to a boil over high heat. Reduce the heat and simmer for 20 minutes, skimming top frequently. Cover partially, leaving only a small opening, and simmer over low heat for 2 1/2 hours. Strain the stock into a large bowl, pressing on the solids. Let cool slightly and refrigerate. Remove the solidified fat from the stock before using.

Note: The stock can be refrigerated for 3 days or frozen for up to 2 months.