Susan, Thank you for your kind words and for trying out our recipes! Your question is a great one. This particular pressure canning recipe has been developed and tested by the University of Georgia Extension. Their expertise assures that the formula is safe for canning without the need for added acid. Therefore, you can be confident following a trusted and secure canning recipe. For reassurance, you can compare this recipe to the Tomatoes with Okra or Zucchini recipe on the NCHFP website.