Canning Tomato Paste

 

3 gallons quartered Roma or other paste tomatoes

1 red bell pepper, seeded and chopped

1 bay leaf

½ tsp. kosher salt

6 tsp. bottled lemon juice, divided

 

In a large pot set over high heat, combine the tomatoes, red bell pepper, bay leaf, and salt. Bring to a boil. Reduce the heat to low. Simmer for 30 minutes, or until the tomatoes are very soft. Using a potato masher, press the tomatoes down and release their juices while they are cooking. Using a food mill, pass the mixture through to puree. Discard the seeds and skins. Transfer the puree to an uncovered slow cooker set on low.  Cook the tomatoes for 8 hours, stirring hourly. As it thickens and reduces, check more frequently to prevent scorching. Prepare a hot water bath. Place the jars in it to keep warm. Wash the lids and rings in hot, soapy water, and set aside. To each jar, add 3/4 tsp. of lemon juice. Ladle the hot paste into the prepared jars, leaving 1/2 inch of headspace. Use a nonmetallic utensil to release any air bubbles. Wipe the rims clean and seal with the lids and rings. Process the jars in a hot water bath for 45 minutes. Turn off the heat and let the jars rest in the water bath for 10 minutes. Carefully remove the jars from the hot water canner. Set aside to cool for 12 hours. Check the lids for proper seals (see here). Remove the rings, wipe the jars, label and date them, and transfer to a cupboard or pantry. Refrigerate any jars that don’t seal properly, and use within 3 weeks. Properly sealed jars will last in the cupboard for 12 months. Once opened, refrigerate and consume within 3 weeks.