How To Can Diced Tomatoes
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There are several reasons it’s a great idea to can your own tomatoes.
The first reason is this: BPA’s. Nearly everyone’s heard of this chemical because of the health risks associated with it. Sadly it continues to be used in so many of our food products. In the case of tomatoes, it’s used in the lining of the cans. Because tomatoes are high in acid, the BPA is more likely to leach out.
So what about cans that advertise BPA-free? Sure, they’ve removed the BPA but in doing so simply replaced it with another chemical called BPS-Bisphenol S. that comes with many of the same health risks.
The good news: Food in GLASS jars is SAFE from chemicals.
Another reason is quality and freshness. You have complete control over which tomatoes you select to go into the jars. Choose the best and you have a superior product.
Lastly, if you’re able to find a good deal on bulk tomatoes, you can bottle your own for the same or less than what you pay for them in the store AND they’re fresher AND are free from those nasty chemicals. It’s a win-win!
Let’s get started!
Bring a large pot of water to a boil. Using a knife, cut a small “x” in the bottom of each tomato and drop the tomatoes in the boiling water, a few at a time, for 30-60 seconds. Lift them out with a slotted spoon and put them directly into a bowl of ice water so they can cool quickly.
Once cool enough to handle, peel the tomatoes. Having blanched the tomatoes, the peels will now slip off easily. Discard the peels.
Cut out the stem part of the tomato and dice the tomatoes.
Place the diced tomatoes and tomato juices into a large pot and bring it to a boil. Boil the tomatoes for 5 minutes to release their juices. Note: If you’re canning crushed tomatoes the process is the same, simply boil a little longer and use a potato masher to crush the tomatoes.
Have the canning jars ready: Sterilized and hot. Place one tablespoon of bottled lemon juice (not fresh) OR 1/4 teaspoon citric acid in each pint jar or two tablespoons lemon juice OR 1/2 teaspoon citric acid in each quart jar.
Pack the hot diced tomatoes and their juices in the hot sterilized jars, leaving 1/2 inch headspace from the top of the jar.
Optional, Salt: Place 1/2 teaspoon of kosher salt in each pint jar or 1 teaspoon in each quart jar.
Use a slim utensil like a butter knife to slide down into the jars to remove any air bubbles. Wipe the rims of each jar and screw on the canning lids/bands.
Place the jars in the boiling water bath canner and process for 35 minutes for pints and 45 minutes for quarts, adjusting for altitude. Remove the jars, being careful not to tilt them. Let them sit undisturbed for 24 hours then check the seals.
These diced tomatoes will keep in a cool place for at least a year.
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How To Can Diced Tomatoes
Ingredients
- Fresh tomatoes figure on roughly 2-3/4 lbs tomatoes per quart jar
- Bottled lemon juice or citric acid: 2 tablespoons bottled lemon juice per quart jar or 1 tablespoon per pint jar OR 1/2 teaspoon citric acid per quart jar or 1/4 teaspoon per pint jar
- Salt optional: 1 teaspoon per quart or 1/2 teaspoon per pint jar
Instructions
- Bring a large pot of water to a boil. Using a knife, cut a small "x" in the bottom of each tomato and drop the tomatoes in the boiling water, a few at a time, for 30-60 seconds. Lift them out with a slotted spoon and put them directly into a bowl of ice water so they can cool quickly.
- Once cool enough to handle, peel the tomatoes. Having blanched the tomatoes, the skins will now slip off easily (removing the skins is the standard recommendation because it's the skins that harbor potential bacteria). Discard the skins. Cut out the stem part of the tomato and dice the tomatoes.
- Place the diced tomatoes and tomato juices into a large pot and bring it to a boil. Boil the tomatoes for 5 minutes to release their juices.
- Have the canning jars ready (sterilized and hot). Place one tablespoon of bottled lemon juice (not fresh) OR 1/4 teaspoon citric acid in each pint jar or two tablespoons lemon juice OR 1/2 teaspoon citric acid in each quart jar.
- Pack the hot diced tomatoes and their juices in the hot sterilized jars, leaving 1/2 inch headspace from the top of the jar.
- Optional, Salt: Place 1/2 teaspoon of kosher salt in each pint jar or 1 teaspoon in each quart jar.
- Use a slim utensil like a butter knife to slide down into the jars to remove any air bubbles. Wipe the rims of each jar and screw on the canning lids/bands.
- Place the jars in the boiling water bath canner and process for 35 minutes for pints and 45 minutes for quarts, adjusting for altitude. Remove the jars, being careful not to tilt them. Let them sit undisturbed for 24 hours then check the seals.
- These diced tomatoes will keep in a cool place for at least a year.
Hi, I’m Kimberly Killebrew and welcome to Daring Gourmet where you'll find delicious originals, revitalized classics, and simply downright good eats from around the world! Originally from Germany, later raised in England, world-traveled, and now living in the U.S., from my globally-influenced kitchen I invite you to tour the world through your taste buds!
Can you add fresh basil
Hi Mary, absolutely!
Thank you
This is my first time canning tomatoes, I’m very excited
Awesome! The important thing is to be sure to include the right amount of either bottled lemon juice or citric acid. Happy canning! :)
Thanks for the easy tutorial. I made my first batch of canned diced tomatoes following your instructions. From a pre-eaten point of view, everything went very well!
Awesome, Charles, congrats on your first batch!
Any suggestions to get rid of the tomato seeds?
Hi, I don’t use bottled lemon juice or citric acid, but I have 6% vinegar, presumably that would be a good substitute?
Thanks.
Do you know what the patent jars with reusable glass kids and metal rings are called? I don’t want to be tied into buying metal lids :)
Hi tj, the sources I’ve read say you should use 4 tablespoons of 5% vinegar (not 6%) per quart to ensure the correct pH level for safe canning. That’s a lot of vinegar and would obviously impact the flavor of the tomatoes, but that is an alternative option.
That’s great, thanks for your reply, I am just about to preserve some now and I sometimes putca little sugar and vinegar into my fresh tomato sauces so to give zing, so it’ll probably be fine:)
Excellent tutorial! It’s been years since I’ve canned tomatoes. But I couldn’t pass up the sale I found this morning. :)
Thanks so much.
Hi, I didn’t see these instructions first.. I watched a YouTube video and canned tomatoes. I blanched and removed the skins and stems but I didn’t ‘cook’ my tomatoes before canning them. They look good except for the fact that they sperated. I used the wide mouth jars. Do you think they will be ok since I didn’t cook them for 5 minutes first? They only come in the jars for 40 minutes.
Hi Kathleen, that’s fine as long as you still used either citric acid or lemon juice. The method is the difference between what is called “raw pack” versus “cold pack.” And yes, using wide mouth jars can sometimes result in the tomatoes floating to the top and the liquid being at the bottom, that’s normal and it’s perfectly safe. You can help avoid that from happening by using regular mouth jars because the diagonal slant toward the mouth will help push the tomatoes down.
Thanks!! I will be using the recipe this week with all the romas from my garden. Thanks for explaining the blanching process. I always forget.
Hi Kimberly! My tomatoes and the liquid separated after they cooled. So basically there is liquid in the bottom of the jars and the tomatoes at the top. Is this normal? And is it still ok to eat? The jar lids processed correctly. This is my first time canning so I want to make sure I’m not going to make my family sick! :)
Hi Kristen, yes, they’re perfectly safe and that’s something virtually every canner experiences at some point. Using regular jars (instead of wide-mouth jars) can help prevent that because the “shoulders” at the top of the jar help push the tomatoes down, but sometimes it just happens anyway.
Awesome instructions..turned out great
Fantastic, Jo, thank you!