• If you are using raw chicken, first roast the chicken pieces. This is optional but it gives the stock a richer flavor than using raw. Add the meat to a sheet pan and roast for one hour at 400 degrees. Flip halfway through to brown on both sides. 
• Add the chicken a large pot. If you roasted the meat beforehand, use a wooden spoon to get up all the brown bits on the sheet pan and add to the pot. Add the quartered onion, roughly chopped carrots and celery, thyme, peppercorns and 16 cups of water. (Be sure it is enough water to cover all the ingredients) 
• Add to the stovetop and bring to a boil. Once it starts boiling reduce to a low simmer. Keep at a gentle simmer for 3-4 hours. The liquid will reduce about 25% percent. If you notice it is reducing too quickly reduce the heat or add more water to ensure all the meat/bones are covered with water. 
• After 3-4 hours and it has reduced by about 25%, remove from the heat and stir in salt. I like to use 1 tsp of salt, but you can adjust according to your taste and personal preference. Give the stock a taste and adjust as you'd like. 
• Next, I like to let it sit for about 30 minutes to allow it to slightly cool. When you are ready, strain the liquid from the solids. To do this, add a colander to a large bowl and pour the broth inside. Next I like to pour the broth through a fine mesh strainer to get all of the smaller pieces out. 
• Next, pour into quart jars or glass containers. You should get about three quarts of stock. Let the stock sit at room temperature until it has cooled and then add to the fridge to store. Or, for immediate use, add to your favorite soup recipes.  
• As the stock cools, there will be a layer of fat that will float to the surface. If you'd like to remove the excess fat you can skim it off with a spoon. Or leave it in for more richness.

To freeze:

• Store the stock in the fridge so it is cold before you add to the freezer. You can pour the stock into a freezer bag, or an airtight container. Be careful storing it in glass jars because when liquid freezing it will expand. When you are ready to use, you can either let it defrost in the fridge or add the frozen portions directly to a pot and heat until melted and warmed through.