free range poultry giblets, neck, wing tips, feet (optional but infuses additional gelatin), and bones (you can mix and match bones--I often throw chicken bones in when I make turkey stock for example)
In a stainless steel stock pot, add the chicken parts, bay leaves, celery, carrots, onion, garlic, and vinegar. Pour enough water to totally cover everything and then some (at least 5 cups worth of water). Put a heat safe (non-plastic) plate in the liquid over the ingredients to keep them submerged. Bring to a full-rolling boil. Cover, reduce the heat to low, and allow to simmer for 4 hours.
After 4 hours, add the thyme and parsley (whole) to the stock and allow to simmer, covered, for one more hour.
Strain the stock through a fine mesh sieve. Discard (or compost or otherwise use) the vegetables and herbs.
Add salt and pepper to taste.
Store the poultry stock in an airtight container in the refrigerator for up to 5 days.