Place chicken carcass into large stock pot.
Add celery, carrots, onions.
Tie fresh herbs together and place into the pot.
Using a vegetable peeler, peel the skin of the lemon and add to the pot. Be careful not to add the white pith part of the lemon.
Add salt, pepper corns and garlic.
Fill pot almost the the top with water and set on high heat just until the pot comes to a boil. Once it has started to boil, turn the heat to medium or medium low, what ever temperature that will keep a nice low simmer.
Let simmer for 6-7 hours
Check pot occasionally to see if you need to add more water.
After it has simmered for several hours, remove from heat and strain your stock with a fine meshed strainer. Place in an air tight container and put in refrigerator for several hours.
Once the stock has fully chilled, remove from refrigerator and using a spoon, remove the fat that has solidified onto the surface of the stock.
Store in refrigerator for 2-3 days or in the freezer for 3-6 months.