Slice carrots, celery, and onion. In a 4-quart Dutch oven combine vegetables, wine or vinegar, lemon, bay leaf, peppers, 8 cups water, and 2 teaspoons salt. Bring to boiling. Reduce heat. Cover; simmer for 30 minutes.
Strain broth through cheesecloth. Use as directed in recipe. Store unused broth in the refrigerator for three days or in the freezer for up to 6 months. Makes 8 cups. (Makes 7-1/4 cups if vinegar is substituted for wine.)