Step 4: Cook Tomatoes
In a large Dutch oven, add one-sixth of tomatoes. Using a wooden spoon or mallet, crush tomatoes. Heat over medium-high heat, stirring occasionally. Add remaining tomatoes. Bring to a boil; reduce heat to medium. Simmer 5 minutes, stirring frequently. Remove from heat. Proceed immediately to Step 5.
Step 5: Prep Jars for Filling
Working quickly and using heat-proof gloves and jar lifters, remove jars from hot water, draining jars. Place on a clean kitchen towel. (Cover pot, and increase heat to high to bring water back to boiling.) Fill each jar with 1 tablespoon bottled lemon juice. (Add 1⁄2 teaspoon salt to each jar, if desired.) Using a wide-mouth funnel, transfer hot tomato mixture to jars, filling to within a half inch of rim. Carefully tap jars on counter to settle tomato mixture and remove air bubbles; add more tomatoes, if needed.
TIP: Proper Headspace
Headspace refers to the area in between the surface of the filling and the rim of the jar. Your target is a half inch of headspace. Too full, and you won’t get a good seal. Too much air, and you open the door for bacteria.
About Bottled Lemon Juice: When it comes to canning, the key to food safety is proper pH. Fresh lemons vary in acidity; bottled lemon juice has a consistent acidity level that makes it the safest choice for canning.
