I use the pot and lid, the jar rack, the funnel, the jar lifter, and the lid wand. I also use a chopstick, a measuring cup with a handle, a measuring spoon, and sometimes a large spoon for stirring. One other item you might not expect: You need either a bottle of citric acid (available in canning sections of stores or from a pharmacy), or a bottle of commercial lemon juice.
Yes, you can can tomatoes! It’s easy to do and you may already have all the equipment you’ll need in your kitchen. You need a deep stockpot, a few other pots, tongs, and a chopstick, though dedicated canning equipment is relatively inexpensive and it will last for decades. Your stock pot needs to be about 2 inches deeper than your canning jars are tall. A packaged set of canning gear might include a canning pot, a jar rack, a canning funnel, a jar lifter, and a lid wand. You can find such sets for around $50, or make up your own by buying a canning pot and a set of tools.
Once you have the gear, you need canning jars, lids, and bands. Don’t use jars that came from the grocery store filled with pickles, mayonnaise, or other products; always use jars specifically manufactured for home canning. Canning jars usually come with lids and bands, so you shouldn’t have to buy extras for your first canning project.
The photos on this page show how to can tomato chunks; follow them if you want to create your own store of tomatoes to use throughout the year.
Preparing tomatoes for canning is time-consuming. Speed it up by cooking them in boiling water to loosen the skins. I boil about a gallon of water and gently add five or six tomatoes at a time. I set a deep-fryer scoop on the tomatoes to hold them under water and leave them for 45 seconds. Then I fish them out and immediately float them in a bowl of cold water.
I core a tomato by cutting a cone of material out around the margins of the scar where the stem was attached. Then it’s easy to pinch the edge of the cut skin between my thumb and the knife blade. Because of its 45 seconds in boiling water, the skin nearly slides off the tomato. Inspired by an online acquaintance, I saved the skins from all the tomatoes, dehydrated them, and ran them through a blender; I’ll use the powder to make tomato soup on some cold winter’s day.
It took about 23 peeled tomatoes to overfill a one-gallon food storage container. Usually, I’m preparing homegrown tomatoes that are a bit more challenging than these “perfect” canning tomatoes.
Once I’d peeled enough tomatoes to fill the canning pot (the pot can handle 10 pint jars at once), I washed out canning jars, set them in the canning pot to boil, and set lids and bands in a pot to heat up—this would take some time, and they’d be heating while I cut up the peeled tomatoes. In most cases, you shouldn’t let canning lids boil; just get the water very hot. The burner control knob on my (cringe) electric stove goes to nine, and I set it to three. As for the canning jars: Fill them and the canning pot so the jars are about one inch under water and set that burner on high heat.
You need to cut the tomatoes into pieces that will fit into your canning jars. My mom used to can tomato quarters, but I like to make fork-sized chunks. With these larger tomatoes, I cut them into eight segments, then I cut each segment into three or four pieces. It took about 18 tomatoes to fill the one-gallon food storage container.
Before you finish cutting up tomatoes, start a third pot of water on the stove—you’ll add boiling water to each jar as you pack tomato pieces. You’ll need about a cup of water per pint you expect to fill—so, for 10 pints, I’d heat three quarts of water.
When the water in the canning pot and the additional pot is boiling, lift a jar out of the canning pot and pour the water from it back into the pot. Set the hot, empty jar on a plate, and put in a quarter teaspoon of citric acid powder or a tablespoon of commercial lemon juice. This is critical to ensure there is enough acid in the jar to kill clostridium botulinum—the microbe that causes botulism. Fill the jar to within a half inch of the top with tomato chunks, then add boiling water to within ½ inch of the top.
Use a chopstick or something like it to release air bubbles from among the tomatoes. When you do this, you’ll gently pack the chunks and things will settle into the jar. Top up the contents with a tomato chunk or two and boiling water so the chunks are underwater and there is a half inch of air space between the top of the jar and the water in it. If you’ve splashed, wipe the rim and threads of the jar clean.
Fish a hot lid out of the pot and set it on the jar, sealant-side-down. Fish out a hot band, and screw it onto the jar. Make the band “finger tight” which can be pretty snug, though please don’t hurt yourself when you tighten it down.
Set the jar back in the canning pot—you may be able to handle the jar at this point, but don’t dip your fingers in the water or burn your wrist on the side of the pot. To remove jars from the pot, use a jar lifter (as you can see on the right). Empty the first five or so jars back into the canning pot but empty the rest into your sink or you may overfill the canning pot. CAUTION!!! Don’t pour boiling water out of a fresh jar onto a packed and lidded jar; the water may splash back onto your hand or wrist and that can hurt. This from someone who has made the mistake at least once a year for nearly 20 years.
With the last filled jar in the canning pot, make sure there is one to two inches of water above the tops of the jars and that the water is boiling. Then set a timer for 40 minutes. When it goes off, remove the canning pot from the heat and lift the jars out onto a cooling rack or a towel on the counter. Let them cool to room temperature—this may take four to eight hours.
Remove the bands and make sure the lids bow down in their middles. You should be able to lift a jar by its lid. If any isn’t sealed, either replace the lid and boil the jar again for 40 minutes, or store the jar in your refrigerator and use it within a week. Damp-wipe the jars—especially the threads—so they won’t be sticky, and store the jars in a cool, dry place without bands on them.
YES! Canned tomatoes float. If you’ve packed the jars well, there may be an inch of nearly clear liquid at the bottom of each one. I’ve heard people complain that fully half their jars are liquid. If that happens to you, be a bit more aggressive packing in tomato chunks when you can your next batch… just don’t crush the tomatoes into the jars (seriously: when you pack tomatoes by crushing them, they need to cook much longer in the boiling water bath).