Combine everything in a large stockpot, adding salt as desired (be careful not to oversalt at this point; you can always add more at the end). Bring to a boil, then lower the heat and simmer 15 to 30 minutes, depending on desired intensity of flavor. Strain through a fine sieve to remove solids, if desired; cool completely before using or refrigerating in airtight containers, up to 2 days.
