<<Disclaimer: Verify this information before applying it to your situation.>>

          SUMMARY

          Thanks to all of you who provided prompt responses. I learned--just
          in time for Evan's lunch!--that Heinz ketchup is made with white
          vinegar from *corn*. Its gluten-free! For anyone who wants to avoid
          all white vinegar, Tree of Life brand ketchup is made with cider
          vinegar and may be available from your health food store.

          ...Pam