I've been told that to can tomatoes safely, you must add acid?
Tomatoes were once considered an acid food that could be safely canned in a boiling-water canner. However, because of problems in recent years with botulism in home-canned tomato products, certain precautions must now be taken. In Missouri, it is recommended that tomatoes have acid (in the form of crystalline citric acid or bottled lemon juice) added. Please refer to GH 1456, "Tantalizing Tomatoes" for safe canning directions.
Barbara Willenberg, Nutritional
Sciences, University of Missouri-Columbia
Last update: Tuesday, May 05, 2009