How much lemon juice or citric acid should I use when canning tomatoes?
Add 1 tablespoon bottled lemon juice to pints and 2 tablespoons bottled lemon juice to quarts of tomatoes. Or add one-fourth teaspoon crystalline citric acid to pints and one-half teaspoon crystalline citric acid to quarts of tomatoes. Acid can be added directly to jars before filling. Four tablespoons of 5 percent acidity vinegar per quart may be used instead of lemon juice or citric acid, however, it may cause undesirable flavor changes.
Note: Add sugar to offset acid taste if desired.
Note: Don't use fresh lemon juice as it's acidity varies. Tomato canning tablets should not be used as they are ineffective.
Barbara Willenberg, Nutritional
Sciences, University of Missouri-Columbia
Last update: Tuesday, May 05, 2009