You can use a whole chicken carcass or a combination of bones from leftover chicken wings, thighs, and breasts. Or you can buy a pre-cooked rotisserie chicken and save the bones. You freeze the bones in a container or freezer bag for up to one month.
You can pour the stock into mason jars and use a tea strainer to remove any solids from the stock. Leave one inch of space from the top to allow for expansion when you freeze your stock, otherwise the glass could crack in the freezer. Cover with the mason jar lid when it’s cooled.