Step 1

Start by chopping the onions, celery, garlic, and basil.

Step 2

Select tomatoes that are fresh, ripe and firm. Wash, core and remove any bruised or soft spots from the tomatoes. Place a large pot on the stove over medium-high heat. Quarter a third of the tomatoes and quickly add them to the pot. Use a potato masher or something similar to gently smash and break down the tomatoes, stirring frequently. Quarter another third of the tomatoes and add them to the pot, continuing to smash and stir. Quarter and add the remaining third of tomatoes, then add the onion, celery, garlic, and basil.

Step 3

Simmer tomato mixture, stirring frequently, for 15 minutes or until tomatoes are broken down and vegetables are soft.

Step 4

Press tomato mixture through a sieve, food mill or fine mesh strainer, to separate the juice.

Step 5

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.

Step 6

Wipe the rims of the jars with a clean paper towel, then place the sterilized lid on top of the jar. Thread ring onto the jar and tighten until fingertip tight.

Step 7

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.