In large pot, combine all ingredients. Add 8 cups cold water and bring to a boil over high heat. Reduce heat to low, cover partially and simmer 45 minutes.
Pour stock through strainer into clean pot or storage container; discard solids. Even though vegetables have been washed, watch for grit that may have settled at bottom of pot. For a richer, more concentrated flavor, continue to simmer strained stock, uncovered, for about 30 minutes. Cool, cover and refrigerate 4 to 5 days, or freeze up to 2 months.