5 Steps for Canning Tomatoes that Taste Garden-Fresh for Months

In the cooking world, we often treat tomatoes as a vegetable even though they're actually a fruit. Canning is a culinary exception. Because tomatoes have high acidity, they are canned like other fruits in a boiling-water canner with only a splash of added citrus or vinegar (but we'll show you how to pressure-can tomatoes, too). You can process them whole, crushed, halved, or stewed. We'll also show you how to can tomatoes in Mason jars no matter which way you cut (or crush) them. Home-canned tomatoes will bring a garden-fresh taste to soups, stews, chilis, and spaghetti sauce all year long.

For each pint of canned tomatoes, you will need 1¼ to 1½ pounds ripe tomatoes; for each quart, you'll need 2½ to 3½ pounds ripe tomatoes. Choose unblemished tomatoes for canning and wash well in cold water. Once your tomatoes are ready, follow our instructions below for peeling, canning, and preserving fresh tomatoes.

Step 1: Sterilize the Canning Jars and Lids

Before you start any canning recipe, you need to have clean and sterilized canning supplies. Here are the tips to get started.

• Wash your empty canning jars in hot, soapy water, and rinse them thoroughly.
• Place jars in a boiling-water canner.
• Cover the jars with hot water; bring to a simmer over medium heat.
• Let the jars simmer 10 minutes, then keep them hot in the simmering water until you're ready to fill each one. When you're ready to start filling them, remove one sterilized jar at a time from the water and place it on a clean kitchen towel to prevent it from slipping while you fill it.
• While the jars are simmering, place the lids in a bowl and pour some hot water from the sterilizing pot over the tops of the lids. Do not boil the lids, and keep in mind that the screw bands don't need to be sterilized.

Step 2: Peel Tomatoes

Your tomatoes will keep much better over time if you get rid of those pesky peels. Here's a quick trick to remove them when peeling a large batch:

• Start with firm, unblemished tomatoes, and wash them well in cold water.
• To remove the skins, dip tomatoes in boiling water for 30 seconds or until the skins start to split. Immediately place the tomatoes in cold water.
• When cool enough to handle, remove the skin and core with a paring knife or with your hands. If desired, cut the tomatoes in half. If you want to know how to can diced tomatoes, you can also halve and dice them at this point.

Step 3: Fill Jars with Tomatoes

When you're filling your jars, add lemon juice and pay attention to headspace. If you overfill or underfill the jars, they won't seal properly during processing. Here's how:

• Place a wide-mouth funnel in a hot, clean pint or quart canning jar.
• Ladle whole or halved tomatoes into the jars, along with any juices from preparing the tomatoes.
• Add 1 Tbsp. lemon juice to each pint jar or 2 Tbsp. lemon juice to each quart jar (the lemon juice raises the acidity of the tomatoes to ensure safe canning).
• Add boiling water, leaving ½-inch headspace.

Step 4: Seal and Process Jars

Once your jars are filled, it's time to start the real canning process. Follow these instructions for processing your tomatoes in a boiling-water canner:

• Remove the funnel; wipe the jar rim with a clean, damp towel to remove all traces of food. Food on the rim prevents a perfect seal.
• Position the prepared lid and screw band on the jar and tighten according to the manufacturer's instructions.
• Set each jar into the canner as it is filled. The jars should not touch. Cover the canner.
• You will need to process the tomatoes in a boiling-water canner for 40 minutes for pints and 45 minutes for quarts. Begin timing when the water returns to boiling.

Step 5: Check the Seal

When your jars are finished processing, it's important to double-check the seal before you stash them away for later. If your jars aren't completely sealed, they won't be safe to eat later on. Luckily, there's an easy way to check, and you can save any jars that didn't seal if you act quickly enough.

• When the jars have cooled, press the center of each lid to check the seal. If the dip in the lid holds, the jar is sealed. If the lid bounces up and down, the jar isn't sealed. Unsealed jars should be stored in the refrigerator and used within three days, or you can reprocess the tomatoes within 24 hours.
• Label the jars with contents and date. Tomatoes keep their optimum quality for 1 year.

How to Can Crushed Tomatoes

Crushed tomatoes can give you a jump start on future recipes, especially if you're making pizza sauce, chili, or soup. The process is similar to what you'll follow for how to can whole tomatoes, but you'll crush the tomatoes before filling the jars:

• Wash and peel the tomatoes.
• Cut into quarters; add enough tomatoes to a large pan to cover the bottom.
• Crush with a wooden spoon. Heat and stir until the mixture is boiling.
• Slowly add the remaining tomato pieces, stirring constantly. Simmer 5 minutes.
• Fill the jars and add bottled lemon juice and salt (add 1 Tbsp. lemon juice and ¼ to ½ tsp. salt for pints; add 2 Tbsp. lemon juice and ½ to 1 tsp. salt for quarts). Leave ½-inch headspace.
• In a boiling-water canner, process pints for 35 minutes and quarts for 45 minutes.

How to Can Tomatoes with No Added Liquid

Though it can help fill your jar, you don't have to add any extra liquid when you're canning tomatoes if you don't want to. Here's how to do it:

• Wash and peel the tomatoes; halve, if desired.
• Fill the jars, pressing to fill spaces with juice.
• Add bottled lemon juice and salt (1 Tbsp. lemon juice and ¼ to ½ tsp. salt for pints; add 2 Tbsp. lemon juice and ½ to 1 tsp. salt for quarts). Leave ½-inch headspace.
• In a boiling-water canner, process pints and quarts for 85 minutes.

How to Can Stewed Tomatoes

If you can stewed tomatoes, you'll already be partway done if you decide to make pasta sauce or soup in a few months. Starting with 8 pounds of ripe tomatoes, follow these instructions to make and can stewed tomatoes:

• Wash tomatoes and remove the peels, stem ends, and cores. Chop the tomatoes, then measure them (you should have about 17 cups).
• Place the chopped tomatoes in an 8- to 10-quart Dutch oven or kettle. Add 1 cup chopped celery, ½ cup chopped onion, ½ cup chopped green bell pepper, 2 tsp. sugar, and 2 tsp. salt to the Dutch oven.
• Bring the mixture to boiling, then reduce the heat. Cover and simmer 10 minutes, stirring frequently to prevent sticking.
• Ladle the hot stewed tomatoes into hot, clean quart or pint canning jars, leaving 1-inch headspace. Wipe the jar rims and adjust the lids.
• Process in a pressure canner at 10 pounds pressure for 20 minutes for quarts or 15 minutes for pints.
• Allow the pressure to come down naturally. Remove the jars from the canner and cool on racks.

Pressure-Canning Tomatoes

If you have a pressure canner in your cupboard instead of a boiling-water canner, you can learn how to pressure-can tomatoes instead. The basic process is the same. Start by sterilizing jars, lids, and bands, then peel tomatoes and fill each jar (follow the instructions for canning tomatoes with no added liquid). Even if you're using a pressure canner, you still need to acidify your tomatoes to preserve them, so don't forget the lemon juice. Once the jars are filled, follow these instructions for processing:

• For a weighted-gauge pressure canner, process pints and quarts 40 minutes at 5 pounds of canner gauge pressure (PSI) if you're less than 1,000 feet above sea level, and for 40 minutes at 10 pounds PSI if you're over 1,000 feet above sea level.
• For a dial-gauge pressure canner, process pints and quarts 40 minutes at 6 pounds PSI if you're less than 2,000 feet above sea level. If you're between 2,001 and 4,000 feet, use 7 pounds PSI; between 4,001 and 6,000 feet, use 8 pounds PSI; and between 6,001 and 8,000 feet, use 9 pounds PSI.

No matter which method you use, canning tomatoes is one of the best ways to preserve them for the months to come. If you don't have time to can tomatoes, you can still save them for later by learning how to freeze tomatoes. Or you can spend a little extra time in the kitchen and learn how to can tomato sauce and how to can salsa (that way you don't have to use your canned tomatoes to make them later!). Any way you do it, knowing how to can fresh tomatoes (or how to freeze them) will certainly come in handy, especially when you end up with a bumper crop of home-grown tomatoes.