Return juice to the large pot and add sugar and salt. Start with 1/4 cup of brown sugar and taste. If you want it sweeter, add the other 1/4 cup. Bring to a boil, then reduce heat to medium and simmer for 15 minutes. Ladle hot soup into sterilized jars using a sterilized funnel, leaving 1" of headspace. Add in the citric acid (1/2 teaspoon per quart jar, 1/4 teaspoon per pinand stir in with the handle of a long spoon.
Process in a pressure canner for the correct weight and time of pressure indicated on the USDA website. Be sure to check your pressure canner's instruction manual to follow proper procedures.
*Contact your local extension office for information on altitude/temp/timing changes for all canning recipes.