Cover and bring to a boil. Reduce the heat to low and simmer 2 to 4 hours. Skim off any foam that may form.
After the 2-4 hours, turn off the heat and allow the broth to cool slightly. About 30 minutes. Line a mesh strainer with cheesecloth and ladle the stock through into a large bowl.
Allow the broth to cool to room temperature then transfer to the refrigerator for up to a week, or measure 1-2 cup amounts and freeze flat in ziplock bags.