If using a stock pot, dump the bones, water, vinegar, salt, and bay leaves, if desired, in the pot. Cover and bring to boil. Reduce the heat to a very gentle simmer, cover partially, and cook for 12 to 24 hours, skimming any filth that floats to the surface. If necessary, add a little water to keep the bones submerged.

If using a slow cooker, dump the bones, water, vinegar, salt, and bay leaves, if desired, in the pot. Cover and bring to boil. Reduce the heat to low, cover, and cook for 24 to 48 hours, skimming any filth that floats to the surface. If necessary, add a little water to keep the bones submerged.

If using a pressure cooker, dump the bones, water, vinegar, salt, and bay leaves, if desired, in the pot. Cover and cook for 1 to 3 hours in a pressure cooker.