Canning & Freezing Quick-Guides Bulletin #4381, Canning Fruits and Tomatoes In a Boiling-Water-Bath Canner (PDF) Prepared by Ann Hamilton, Food Safety Field Specialist, University of New Hampshire; reproduced with permission. For information about UMaine Extension programs and resources, visit extension.umaine.edu. Find more of our publications and books at extension.umaine.edu/publications/. Acidified tomatoes and fruits are considered