How to Can-It-Forward and Preserve Summer Tomatoes

can-it-forward preserving tomatoes

The first of August marks International Can-It-Forward Day, a celebration of the joys of fresh canning. We can’t think of a better way to join in the festivities than to preserve those rubies of the South—ripe summer tomatoes.

For many of us, however, “putting up” is a thing of the past—the handiwork of our mothers and grandmothers. They filled their kitchens (and our memories) with the sounds of jostling jars, rattling pot lids, and the jack-in-the-box pops of perfect seals as they hurried to preserve summer’s bounty before winter transformed it into memory.

But their hallowed craft is no lost art; it’s simply a skill waiting to be learned. We visited Preserving Place in Atlanta, Georgia, where owner Martha McMillin walked us step-by-step through putting up tomatoes.

Follow along, and learn how to reclaim this treasured pastime.

What you’ll need:

can-it-forward preserving tomatoes
• 7 (1-pint) canning jars, lids, and rings, rinsed
• Canning equipment (see left)
• Approximately 12 1⁄4 pounds fresh tomatoes
• 1⁄2 cup bottled lemon juice
• 3 1⁄2 teaspoons kosher salt (optional)

Step 1: Sterilize Jars & Lids
In a large stockpot or canner, fill with water to three-fourths full. Set jars in pot, submerging to sit flat. Add water to within 2 inches of rim of pot. Bring to a boil over high heat. Cover, and reduce heat to medium. Keep jars warm.

TIP: Don’t Boil Lids
Boiling water is too hot for jar lids; it can compromise the rubber seal. Heat lids in a small saucepan of barely simmering water for 10 minutes.

Step 2: Prepare Tomatoes
In a large Dutch oven, fill with water to halfway full. Bring to a boil over high heat. Fill a large bowl halfway full with ice water. Cut a small X in the end of each tomato. Add tomatoes to boiling water; cook until peels begin to pull away, 30 seconds to 1 minute. Using a slotted spoon, transfer tomatoes to ice water. Let cool 1 to 2 minutes. Quickly remove tomatoes from ice water.

Can-It-Forward step 2 preserving tomatoes


Step 3: Peel & Seed Tomatoes
Place a colander over a large bowl. Peel tomatoes over colander, breaking open with your fingers to remove as many seeds as possible. Place seeded peeled tomato pieces in another large bowl. Press solids against side of colander to extract juice; discard peels and seeds. Reserve juice.

can-it-forward preserving tomoatoes

TIP: Save the Juice
Refrigerate the juice up to 2 weeks, or process it separately. It’s perfect for soups, sauces, and Bloody Marys.

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.

can-it-forward cook tomatoes


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.


can-it-forward preserving tomatoes

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.

Step 6: Wipe & Seal Jars
Working quickly, wipe rims of jars with a clean damp paper towel. Top jars with lids and rings. Using your fingertips, tighten lids just until closed.

can-it-forward preserving tomatoes

TIP: Fingertip Tight
Resist the urge to screw on the lids super tight. Tighten using just the strength of your fingertips—just until the lid catches and doesn’t wobble.

Step 7: Process Jars
Place a canning rack in stockpot or canner. Using heat-proof gloves and jar lifters, transfer sealed jars to rack, setting upright. Lower rack into boiling water. Bring water back to a rolling boil. Cover, and boil 40 minutes. (If needed, add additional water to cover jars by 2 inches. Increase boil time to ensure jars boil for full 40 minutes.)

can-it-forward preserving tomatoes

Step 8: Remove Jars & Let Rest
Line a rimmed baking sheet with a kitchen towel. Using heat-proof gloves and jar lifters, carefully remove jars from canner, keeping jars level. Place on prepared pan. Let cool 24 hours. (Jars will make a faint popping sound as they cool.) Label and date jars; store sealed jars in the pantry up to 1 year. Store opened jars (or jars that don’t seal properly) in the refrigerator up to 2 weeks.

can-it-forward preserving tomatoes

TIP: The touch test
After jars have cooled for 24 hours, test for a proper seal by pressing jar lid; if it feels firm and doesn’t pop up and down, a proper seal has been achieved.


This how-to originally ran in July/August 2014 . Order the issue online for all of its timeless tips.



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