Place chicken, vegetables, and herbs and spices in 12-quart stockpot and add cold water.
Bring to boil then turn heat down to medium low to maintain a gentle simmer.
Skim the scum from the stock every half hour or so. Add hot water as needed to keep bones and vegetables submerged. Simmer uncovered for 6 to 8 hours.
Strain stock through a fine mesh strainer into another large stockpot or heatproof container discarding the solids.
Cool immediately in large cooler of ice or a sink full of ice water.
Place in refrigerator overnight. Remove solidified fat from surface of liquid and store in container with lid in refrigerator for 2 to 3 days or in freezer for up to 3 months. Prior to use, bring to boil for 2 minutes. Use as a base for soups and sauces.