This recipe is from my book, The Davis Farmers Market Cookbook, Revised Edition, available in November, 2016.
I dedicate a day to ketchup each summer,. I triple this recipe to make 12 pints and simmer it all day. If you are making a single recipe, 1 to 2 hours of simmering is adequate. Once you’ve made your own ketchup, you’ll find it hard to return to store-bought.
10 large, very ripe red tomatoes or a combination of different colors and varieties (about 5 pounds)
2 large yellow or red sweet peppers (about 11/2 pounds), seeded and coarsely chopped
2 yellow onions (about 10 ounces each), coarsely chopped
10 cloves garlic, coarsely chopped
1 cup white wine vinegar
Grated zest and juice of 1/4 lemon
3/4 cup sugar
11/2 teaspoons salt
2 teaspoons mustard seeds
1 tablespoon black peppercorns
1 tablespoon coriander seeds
1 teaspoon whole cloves
1-inch piece cinnamon stick
1-inch piece fresh ginger, cut into 3 or 4 pieces
You will need four pint canning jars with lids and rings, a large canning kettle with a rack and cover (or a large, wide pot with a wire rack and cover) for the water bath, a large, nonreactive pot for cooking the ketchup, a large saucepan for blanching the tomatoes, canning tongs, and a ladle.
Fill a large saucepan three-fourths full with water and bring to a boil over high heat. Have ready a large bowl of ice water. In batches, add the tomatoes to the boiling water and leave for 1 minute to loosen the skins, then scoop them out and plunge them into the ice water. With a paring knife, peel away the skins and cut out the cores. Cut the tomatoes in half crosswise and squeeze each half gently to remove the seeds, using your fingertip to dislodge any seed sacs that do not fall out easily.
In the large, nonreactive pot over medium heat, combine the tomatoes, sweet peppers, onions, garlic, 1/2 cup of the vinegar, and the lemon zest and juice and cook, stirring frequently, until the vegetables are cooked through and soft, 15 to 20 minutes. Remove from the heat and let cool slightly.
Working in batches, transfer the vegetable mixture to a blender or food processor and process until coarsely puréed. Return the purée to the pan and add the sugar, salt, and the remaining 1/2 cup vinegar. In the center of an 8-inch square of triple-layered cheesecloth, combine the mustard seeds, peppercorns, coriander seeds, cloves, cinnamon stick, and ginger. Gather up the corners and tie them with cotton string to make a spice bag. Add the bag to the pan holding the purée.
Return the pan to low heat, bring the mixture to a simmer, and cook, stirring occasionally, until it thickens, 1 to 2 hours. Watch carefully so it does not burn. The finished ketchup will be slightly thinner than most commercial ketchups.
While the ketchup is simmering, set up the water bath. Fill the canning kettle with water (the water must be deep enough to cover the jars by 1 to 2 inches) and bring to a boil over high heat. If you don’t have a canning kettle, use a large, wide pot and put a wire rack in the bottom of the pot before you fill it with water. Once the water boils, you can turn off the heat and then return the water to a boil just before you are ready to put the jars in the kettle.
Wash the canning jars in hot, soapy water and rinse well. Place the jars in a saucepan, add water to cover generously, and bring to a boil over medium-high heat. Boil for 15 minutes, then turn off the heat and leave the jars in the hot water until you are ready to fill them. Fill another saucepan half full with water and bring to a boil over medium-high heat. Add the canning lids and rings and boil for 5 minutes. Turn off the heat and leave the lids and rings in the hot water until needed.
Just before the ketchup is ready, using tongs, transfer the jars to a work surface. Return the water in the canning kettle to a boil. Ladle the hot ketchup into the hot, sterilized jars, filling them to within 1/2 inch of the rim. With a clean, damp cloth, wipe the rim of each jar. Place a lid on the rim and then screw on a ring, being careful not to screw it on too tightly. Put the filled canning jars into the rack of the canner and lower the rack into the boiling water. If you are using a large, wide pot, use the canning tongs to lower the jars onto the rack in the bottom of the pot, making sure the jars do not touch. Return the water to a rolling boil, reduce the heat slightly, cover, and boil for 10 minutes.
Cover a work surface with a folded towel. Using the canning tongs, transfer the jars to the towel, spacing them a few inches apart. As the jars begin to cool, you will hear popping sounds, which is the sound of the lids sealing. The lids should be indented. When the jars are completely cool, after at least 12 hours, check the seal on each jar by pressing on the center of the lid. If it remains indented, the seal is good. If it does not, refrigerate the jar and use the ketchup within 1 month.
Label the jars with the contents and date and store in a cool, dry place for up 1 year.
Makes 4 pints