1 Rinse chicken bones with cold water and drain well.
2 Coarsely chop the bones.
3 Place chicken bones in a large pot and cover with about 4 liters (approximately 1 gallon) of water. Add the salt.
4 Bring water in pot to a boil, occasionally skimming off any foam from the surface.
5 Meanwhile, peel the onions and carrots. Rinse leeks and drain. Coarsely chop vegetables.
6 Add vegetables and peppercorns to pot.
7 Cook over low heat, uncovered, until broth is very flavorful, about 2 1/2 hours, skimming off skim off any foam as necessary. After broth has finished cooking, pass through a coarse sieve and then again through a fine sieve, discarding solids.
8 Let stock cool completely, then refrigerate overnight to allow fat to rise to the surface. Remove hardened layer of fat the next day.
9 Boil the stock again until reduced to about 1.2 liters (approximately 5 cups).
10 Allow stock to cool again before refrigerating in an airtight container for up to 3 days. To freeze, transfer stock to freezer bags and seal tightly (or freeze in ice-cube trays).
11 Tip: To keep stock for longer, you will need to use a pressure canner and process jars according to manufacturer's instructions, or visit http://nchfp.uga.edu/.