This makes a fabulous soup base. The canned variety doesn't hold a candle to this!
If using a whole chicken, cut off the wings and remove the neck and fat glands. Cut chicken into several pieces.
Place chicken pieces or just bones into a large stock pot with 4 qts. of water, vinegar, onions, carrots, and celery. Let stand 30 min. to 1 hr. Do not heat water.
Bring water to a boil and skim off the scum that rises to the top. If this scum is left in the stock it will ruin the flavor. Reduce heat, cover and simmer for 6-8 hrs. (The longer you cook the stock, the richer and more flavorful. I've let it go for 24 hours.) About 10 min. before cooking time is done, add parsley.
Strain the stock, removing the chicken pieces, vegetables, and bones. Let them cool and remove the meat for other uses. (I usually freeze the vegetables and meat for chicken soup.)
Pour the stock into a large container and refrigerate. If you prefer, skim off the layer of fat that forms on top.
Pour remaining stock into pint jars (equivalent to 14 oz. cans) and freeze. I would not recommend filling jars to the top or they will expand when freezing and crack the glass. Speaking from experience!
If you don't have a whole chicken you can replace it with 2-3 lbs. of chicken parts such as necks, backs, wings OR 3-4 lbs. of chicken bones that have been broken to let the marrow seep out (marrow adds flavor and minerals).