How to Can Tomatoes

Right this way to jarred essence of summer. Food Network Kitchen's tested, detailed method that walks you through all the safety measures necessary.

Updated on August 25, 2023

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Home canned, home grown, crushed, organic tomatoes with two fresh tomatoes on outside garden table with tomato plants in background.


Home canned, home grown, crushed, organic tomatoes with two fresh tomatoes on outside garden table with tomato plants in background.

Photo by: lawcain/Getty Images

lawcain/Getty Images

By Alice K. Thompson and Sean Timberlake for Food Network Kitchen

Alice is a contributing writer and editor at Food Network. Sean Timberlake is a professional writer and the founder of Punk Domestics, a content and community site for DIY food enthusiasts.

As summer's heat wanes, farms and gardens bring in their yearly bounty of tomatoes. Canning is a tried-and-true way to enjoy peak season tomato flavor year-round. Once you’ve got a stash of canned tomatoes, you’ll can use them in homemade tomato sauce of course, but also in many other recipes that typically call for canned tomatoes, from tikka masala to shakshuka. Plus they even look bright and summerlike on the shelf, something that’s hard to say about store-bought ones! Follow our six-step guide and you’ll be enjoying them for months to come.

Photo by: Alice K. Thompson

Alice K. Thompson

What Are the Best Tomatoes for Canning?

For best results you'll want tomatoes with a high amount of meat, such as plum or San Marzano, but most importantly you'll want them ripe. Discard any bruised or overripe fruit or extremely under-ripe fruit; their quality will not improve with canning.

Equipment for Canning Tomatoes

You'll need some basic equipment. For approximately 22 pounds of tomatoes, you'll need:

  1. Six to seven quart-size mason jars with screw rings and new, unused lids
  2. Boiling-water canner, or very large stock pot with a rack or kitchen towel at the bottom to keep the jars from resting directly on it
  3. Ladle
  4. Wide-mouth funnel
  5. Jar tongs (sometimes called jar lifters)
  6. A couple of cooling racks
  7. A few clean kitchen towels
  8. An added acid such as bottled lemon juice; see below

Do Tomatoes Need to Be Canned with Added Acid?

Tomatoes are comparatively low in acidity, and so must be acidified for safe canning. Foods with a pH higher than 4.6 can harbor botulism bacteria spores; tomatoes are generally right around 4.5, so the USDA recommends bringing the acid level up. Moreover, if you add anything to your tomatoes, such as onions, garlic or basil, you’re lowering the acidity further.

Bottled lemon juice is the recommended ingredient to up the acid: Add 1 tablespoon to each pint jar or 2 tablespoons to each quart jar. Why bottled lemon juice? Fresh lemon juice can vary in acidity so it’s not recommended. Citric acid can also be added (1/2 teaspoon per quart, 1/4 teaspoon per pint), although its flavor may be more pronounced than that of lemon juice.

How to Can Tomatoes

Canning involves several distinct steps that can’t be rushed and should be done start to finish, so leave yourself a full morning or afternoon and be sure you’ve got all the equipment you need before you start. The method below is for crushed hot-packed tomatoes, and involves the following steps:

  1. Sterilize Jars and Lids
  2. Core, Score and Blanch
  3. Peel, Crush and Cook
  4. Fill Jars
  5. Seal and Process
  6. Test the Seals

To can the tomatoes with a pressure canner, much of the method is the same, but the actually processing will vary; see the section "Pressure Canning Tomatoes," below, for information.

Photo by: Alice K. Thompson

Alice K. Thompson

Step 1: Sterilize Jars and Equipment

Sterlize your tools. Wash your jars, lids, rings, funnel, ladle and jar tongs in soapy water and rinse.

Sterilize the jars. Place the jars in a boiling-water canner. Cover with hot water and bring to a simmer; adjust the heat and simmer 10 minutes. Leave the jars in the hot water until you’re ready to fill them. If you are preparing a large number of jars, you can run them through the dishwasher (provided it sterilizes), then keep in a 220 degrees Fahrenheit oven until ready. Keep everything hot until just before you're ready to can.

Sterilize the lids. Place new, clean lids in a bowl along with the screw tops. Pour in boiling water and leave them in the water until needed. (A lid caddy is a handy tool to keep things organized).

Photo by: Alice K. Thompson

Alice K. Thompson

Step 2: Core, Score and Blanch

Peeling tomatoes is necessary before canning for quality and safety since the skins can harbor bacteria.

Score the tomatoes. Using a paring knife, cut out the tough stem end of the tomato, then score the bottom with a shallow X. Repeat with the remaining tomatoes.

Blanch the tomatoes. Set a large pot of water to boil; keep a basin full of ice water nearby. A few at a time, submerge the tomatoes in boiling water for 20 to 30 seconds, until the skins wrinkle and split.

Shock the tomatoes. Transfer them with a slotted spoon to the ice water to cool. You'll probably need several changes of ice water as the hot tomatoes melt the ice.

Step 3: Peel, Crush and Cook

Set up your workstation. Wash your hands well, then set up a workstation with three positions: A large bowl, another large bowl or pot with a sieve over it, and a pot large enough to capture the tomato pulp for cooking.

Peel and seed the tomatoes. Remove each tomato from the ice bath. Rub or peel the skin off and discard it into the first bowl. Over the sieve in the second bowl or pot, tear open the tomatoes and remove the seeds and liquid from the chambers with your fingers. Move to the third pot and crush the tomato pulp with your hands into it. Using a spatula, rub the seeds in the sieve to extract the water. Dump the seeds from the strainer into the bowl with the skins. Reserve the flavorful tomato water.

Simmer the tomatoes in tomato water. Place the pot of your crushed tomatoes on the stove. Add enough of the tomato water you've collected from the seeds so there's a good amount of liquid in the pot. You won't need all the water. (Save any remainder for tomato water recipes like Tomato Martini.) Bring to a low boil and reduce heat. Simmer the crushed tomatoes until they break down, about 5 minutes.

Step 4: Fill Jars

Ready the jars and lids. Remove as many jars from the water-bath canner as you will can at once (a 23-quart canner can handle 7 quart jars). Drain lids and screw rings.

Fill the jars with aromatics and tomatoes. Stuff a sprig of basil into each jar, if desired. Add 1 tablespoon bottled lemon juice to pint jars, 2 tablespoons to each if you’re using quart jars. Ladle the tomatoes through the wide-mouth funnel into each jar, leaving 1/2 inch of headroom at the top. Do not partially fill jars since this may interfer with sealing during processing. Refrigerate any leftover puree and use it within in 1 week.

Jars of homemade Peach jam in a boiling water bath.All images in this series...


Jars of homemade Peach jam in a boiling water bath.All images in this series...

Photo by: RonBailey/Getty Images

RonBailey/Getty Images

Step 5: Seal and Process

"Bubble" the jar contents. Insert a clean table knife or chopstick into a jar and "bubble" the contents, wiggling it around the perimeter to dislodge any air bubbles. Add a bit more tomato if necessary to maintain 1/2 inch of headroom. Repeat with remaining jars.

Screw on the lids. Wipe the rims of the jars clean with a damp towel, then set the lids on top. Screw on the rings, screwing until just finger-tight—i.e., tightening them gently but securely with the tips of your fingers, not forcefully with your entire hand.

Lower the jars into the canner. Using the tongs, lower the jars back into the hot water in the canner, making sure that they don’t touch. The jars must be covered by at least an inch of water; add more hot water to the canner if necessary.

Boil the jars. Bring to a gentle boil; adjust the heat and process the jars for 40 minutes for pints, 45 minutes for quarts.

Cool the jars. Turn off the heat and let the jars sit in the water for 5 minutes. Transfer the jars with the tongs to a kitchen towel or rack set over a kitchen towel and cool completely, about 24 hours.

Step 6: Test the Seals

Lift the jars by their lids. Once cool, test the seal of each jar by removing the ring and lifting the jars by the lids. If the lids give, the seal did not set. Unsealed jars of tomatoes may be refrigerated and used right away, or the tomatoes can be processed again using the instructions above.

Label the jars. Label the jars with the date and store in a cool dark place. Use the tomatoes within a year for best quality.

Pressure Canning Tomatoes

Canning tomatoes in a pressure canner is also an option. By raising the pressure in the cooking environment, you raise the temperature at which water boils. At 11 pounds of pressure, you raise the boiling temperature to about 240 degrees Fahrenheit, which is high enough to kill off the spores that cause botulism. If you intend to do much canning of low-acid foods such as tomatoes, stocks or meats, you may want to invest in a pressure canner. Modern pressure canners are easy and safe. Note that the USDA still advises you to add bottled lemon juice (1 tablespoon per pint jar, 2 tablespoons per quart jar) to tomatoes even if you’re using a pressure canner. The following instructions are for a dial-gauge pressure canner at sea level or up to 1,000 feet above sea level; consult your manufacturer’s instructions for specifics for a weighted-gauge canner or for high-altitude canning.

  • Follow the basic process above for sterilizing your jars and equipment.
  • While you fill your jars following the guidelines above, have your pressure canner filled to the 3-quart line and set over a high flame.
  • Using the tongs, lower the filled jars into the canner and close the lid. Keep over high heat until steam flows freely through the vent at the top; continue venting for 10 minutes, then apply the valve.
  • Keep over high heat, monitoring the pressure. When the pressure hits 11 pounds, reduce the heat to low and set the timer for 15 minutes. Keep an eye on the pressure: It can go over 11 pounds, but it's best to keep the pressure as stable as possible. Moreover, if it dips below 11 pounds, it must be brought back up, and the 15 minutes started again.
  • When the 15 minutes are up, turn off the heat and allow to cool naturally. When the pressure has fallen completely and the cover lock drops, open the canner and remove the cans with your tongs to the cooling racks.
  • Cool 24 hours and test the seals as described above.

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