I started canning diced tomatoes several years ago after having an “aha moment” one evening while preparing dinner. As I was opening a can of diced tomatoes that I needed for the recipe I was making, I suddenly wondered why in the world I never tried canning them myself. I mean how hard could it be?
I grew up helping my mom can tomato juice and tomato chunks. And every year since we’ve been married, I’ve canned tomato juice as well as things like salsa and marinara sauce, so I was quite familiar with the process of canning tomatoes.
I decided to give it a try and it worked like a charm! It was not only super simple, it has also saved me from needing to buy diced tomatoes from the store.
How do you can tomatoes? Let me help you learn the process!
SUPPLIES FOR CANNING TOMATOES
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Tomatoes, salt and lemon juice
Dishpan or containers to put the tomatoes in
Knife (This one is my favorite for slicing tomatoes!)
Cutting board (The groove on this one is awesome because it catches the juice, creating less mess.)
Vidalia Chop Wizard (Not a necessity, but you can dice the tomatoes in about half the time if you use it.)
– This gadget is also awesome for dicing tomatoes, onions, and peppers for salsa and potatoes and carrots for soups.
Damp rag to wipe jar rims
Water Bath Canner
Canning jars with lids and rings
Old towels or rags to set the hot jars on
(If you are new to canning and need to buy both the jar lifter and a funnel, it’s cheaper to get this Ball Canning Utensil Set.)
HOW TO CAN DICED TOMATOES- A STEP-BY-STEP TUTORIAL
how do you can tomatoes
1. Wash tomatoes thoroughly.
Cut out the stem and any defects or blemishes.
Some people also peel the tomatoes, but I never do and we honestly have not noticed the peelings at all- and I’m even funny about textures like that in food.
I figure why bother with the extra step, plus it’s a bit healthier too!
canning tomatoes with skins
2. Cut up the tomatoes.
Slice tomatoes into about ½ inch thick slices, then dice them into whatever size you want. I love using my Vidalia Chop Wizard for this!
how to can tomatoes
3. Place diced tomatoes into a clean canning jar.
A funnel makes this super easy. Gently shake the jar to settle tomatoes so that you can fill it completely. The tomatoes should be packed tightly in order to produce enough juice. It won’t hurt if you press down on them a bit to get the jar packed full- in fact, this is probably going to be necessary.
The jar should be full to the base of the neck.
canned tomatoes recipe
4. Add salt and bottled lemon juice.
For the salt, use ½ tsp. per pint and 1 tsp. per quart. You do not need to add salt when canning tomatoes, but I recommend it because I think it helps enhance the flavor.
For the lemon juice, use 1 Tbsp. per pint and 2 Tbsp. per quart.
Once the salt and lemon juice are added to the tomatoes, wipe the rim of each canning jar with a damp cloth to remove any tomato residue that may be there. (If there is even a slight bit of tomato juice on it, it may not allow it to seal properly.)
I updated the original post to include the instructions to add lemon juice after several readers commented and said that to be safe, you really should add it.
canning jar lids in boiling water in pan on stove
5. Prepare the canning lids.
Once you have 7 jars filled, place 7 metal canning lids in a small pan. Cover with water; bring to a boil.
When the water boils, use a fork or lid lifter to lift the jar lids out of the water and place them on the jars. Be careful not to burn yourself!
Secure each lid with a jar band/ring. (Heating the lids softens the rubber, allowing for a better seal.)
diced tomatoes recipe
6. Place the filled jars of tomatoes in the canner.
Once jars are full and have the ring and lids on them, place them in the canner.
Then add hot water to the canner, enough to cover the jars by 1 to 2 inches. Turn the burner on medium high heat.
Once water starts to boil, reduce heat slightly and process for 45 minutes, making sure the water is boiling gently and steadily the whole time. (You may need to adjust heat to keep the boil going nicely, but really, as long as it is boiling, you are fine.)
how to can diced tomatoes
7. Remove the jars of canned tomatoes.
After processing the canned tomatoes for 45 minutes, turn the burner off.
Remove jars using jar lifter- you may want to have a dishrag in your other hand to catch any hot water that drips from the jars as you remove them- and place on an old towel, blanket or another padded surface. (This is to protect your counter from the super hot jars.)
Allow at least a little bit of air space around each jar, making sure not to have jars close enough to touch. Do not move until jars are completely cool.
Jars should seal as they cool and you will typically hear a snap or pinging sound as the vacuum seal is formed. The lids will be slightly concave when sealed.
To test the seal, once jar has totally cooled you can lightly tap the center of the cooled jar lid. If it is firm and does not move, it should be sealed. If it pushes in, it didn’t seal properly. You can still use unsealed jars, just put them in the refrigerator and use them as soon as possible.
After jars are completely cool, you can remove the rings. Jars should be wiped clean before storing them.
HELPFUL TIP: 1 pint of canned diced tomatoes is equivalent to 1 (15 oz.) can of diced tomatoes.