Canning tomatoes that I’ve grown in my garden is one of the summer’s most satisfying chores. I use canned tomatoes all year long to make marinara sauce, soups and chili, so I process as many as possible each year!
Tomatoes are generally processed with a water bath canner, however, what many people don’t realize is that you can process them with a pressure canner as well. The preparation of the fruit is very similar, but the methods are different, I’ll discuss all of that with you.
What Will I Need for Canning Tomatoes?
First, you’re going to need fresh-picked, fleshy tomatoes from the garden for canning!
Oftentimes, I’ll pick up a couple of cases of tomatoes to can, long before my own garden tomatoes are ready. I don’t want to miss a single opportunity to enjoy tomatoes on sandwiches, omelets, pasta or in fresh marinara.
Here’s what you’re going to need:
Beautiful fresh tomatoes
Jar lifter
Canning jars, lids and rings
Salt (1/2 tsp for pints, 1 tsp. for quarts)
Lemon juice (1 tbsp. for pints, 2 tbsp. for quarts)
Various rubber spatulas to release air bubbles in jars
Wide-mouth funnel
A pan or kettle of hot water
The first thing I do before canning tomatoes is to wash my tomatoes in a sink full of cool water, along with a cup or two of vinegar and a few drops of fragrance-free dish soap. Swish them around for a few minutes and give them a good rinse! Put in colander to dry.
Most folks choose to remove the skins of their tomatoes before canning. This is because the skins often come off during the processing in the canner. However, I leave my skins on, it’s just a personal choice.
Removing the skin of the tomatoes is done simply by placing your tomatoes in a wire basket and dipping them into boiling water for 30-60 seconds, you’ll see the skins begin to crack. Then remove from boiling water and plunge right away into ice water in your sink. The skins will slip off easily now.
Now to get started…
Preparing Your Canning Equipment and Jars
Begin by examining your canning jars to make sure they are free from knicks and chips, especially around the mouth, that could inhibit your seal.
Wash your jars, lids and rings in hot, soapy water and then rinse well. Set your rings aside and then place your lids in a pan of water on low heat (do not boil!)
Place your jars into the water bath canner, filling the jars and the canner (about 70% full) with water and heat on the stove. The water should be hot, but not boiling. Keep the jars in the canner until you are ready to use them.
How to Sterilize Canning Jars – Read the whole thing please
Water Bath Canning Tomatoes
Remove one or two jars at a time from your canner, emptying the water from the jar back into the canner. Line your jars up so that you can work and easily fill them, adding a funnel now.
Ball Canning Book recommends putting 1 tbsp. of lemon juice in the bottom of your pint jars and 2 tbsp. in quart jars.
Although tomatoes are considered a high-acid food, the exact acidity is inconsistent.
Adding lemon juice helps to ensure that the acid levels are high enough for water-bath canning.
Then add salt (1/2 tsp for pints, 1 tsp. for quarts).
Canning Tomatoes: Raw Pack
You can slice your tomatoes in any fashion you prefer: whole, crushed or quartered. Once you’ve removed the skins, you are ready to remove the seeds and cut your tomatoes.
After cutting your tomato in half (and taking a whiff of that tomato awesomeness!), use your thumb to swipe out those seeds. You don’t have to get every single one, but get most of them. They make the tomatoes bitter when you cook with them.
I keep a small bowl nearby for the seed collection….you can save the seeds to use next year!
Saving Tomato Seeds
Once the seeds are out, I like to turn my tomatoes flat on the cutting board and slice them.
Remove one or two jars from the hot water, pour the water back into the canner, and line up to fill with tomatoes.
Using a dough scraper (go figure), I scrape the tomatoes off the cutting board and put them directly into the jars.
Aren’t they pretty? I love the look of tomatoes in mason jars!
Keep cutting and filling jars…
Gently press your tomatoes down to make a bit more room, I’m using my blender tool. However, leave room for the hot water to flow between the tomato pieces.
Tomatoes tend to hold a lot of juice. Once canned, you may find an inch or two of head space that you didn’t expect, it’s ok. You didn’t do anything wrong.
While you’re doing all of this, make sure you have some of the correct-sized canning lids on simmer in a saucepan, ready to go. Do not boil them, please!
(I forgot to add salt to my jars at the beginning, so I’m adding it now!) It’s best to add it and the lemon juice at the bottom though!
Now is the time to release any air bubbles inside the jar, I use the clean end of a rubber spatula for this. As the bubbles release, add hot water to the jar from your kettle. Your goal is 1/2″ head space when canning tomatoes.
Like this…..
With a clean, wet cloth, wipe the mouth of the jars clean. I like to dip my cloth in the hot lid water for this. Make sure you don’t leave even the smallest grain of salt or tomato on the lip or the jar will not seal properly.
Using tongs, lift the hot lids from your saucepan and set them directly on the jar.
Then, with one finger holding the lid down, put the rings on finger tight.
Place your full jars into the canner as soon as you finish filling them with your jar lifter, and then take another jar or two out to fill. This keeps the jars hot and less likely to break.
You can use the jar basket to lift them up and down, but I usually just place them in with the jar lifter. Make sure there is a distance between the jars so that water can circulate while cooking.
The water in the canner should cover the canning jars by 2″, add water if needed, before you begin processing.
Once your jars are placed, put the canner lid on and turn the burner on high to bring the water to a boil.
Once the water begins to boil, turn the heat down slightly to maintain a boil and start the timer.
Quarts require 45-minute processing time, pints need 40 minutes.
If your canner is like mine, water likes to boil over a bit. Don’t panic, just keep some clean kitchen towels to sop it up.
DING!
Once the timer goes off, remove the entire canner from the heat and take the lid off. Wait 5 minutes and then remove the jars.
Place a clean kitchen towel nearby and gently lift your jars out of the canner, then place them on the towel.
What a work of art!!
So, there you have it, how to can tomatoes in a water bath canner!
How to Pressure-Can Tomatoes
Wait, is that a thing?
Yes, it is!
You CAN pressure-can tomatoes if you choose to.
What are some reasons you might decide to pressure can your tomatoes?
- It’s a lot faster! It only takes 10 minutes to process in a pressure canner as opposed to 45 minutes in a water-bath canner for quarts!
- Pressure-canning preserves more of the nutritional value of the tomatoes.
- If you just have one water-bath canner, you can alternate with your pressure canner and speed up your canning!
How is Pressure-Canning Tomatoes Different than Water-Bath Canning?
The process of preparing tomatoes for pressure-canning is the same as for water-bath canning.
However, you will heat your jars a bit differently in the pressure canner.
The best way I’ve found to do this is to fill the jars with water and set them in the pressure canner, which should be filled to the suggested water line inside the canner.
As you’re ready to fill your jars with tomatoes, simply remove one jar at a time and empty the hot water out in a sink. (Not back in the canner this time).
You will need to add salt and lemon juice, just as you do with water-bath canning in the bottom of the jar.
Salt: Pints 1/2 tsp., quarts 1 tsp.
Lemon juice: Pints 1 tbsp., quarts 2 tbsp.
Then, fill your jars with tomatoes and then new hot water. (Remember, we want the jar to stay hot!)
Insert a wooden or plastic spoon to eliminate any air bubbles.
Once a jar is full, take a clean cloth and wipe the rims clean, then put on a lid and ring.
Put the jar back into the hot water within the pressure canner, move on to the next jar and finish them all.
Resist the temptation to tighten the rings down too hard when canning tomatoes, finger tight is sufficient.
Follow the instructions for your pressure canner.
Process quarts and pints for 10 minutes with 10 PSI.
Super fast processing!
Tell us how your canned tomatoes turned out and share in the comments!
This Post Has 33 Comments
JoAnne August 16, 2021 Reply
Thank you for all your tips. Canned my garden tomatoes this am using your recipe and suggestions.
Kelly August 17, 2021 Reply
HI JoAnne! You are so very welcome, I’m glad that you had success today!
Lori August 19, 2021 Reply
Can I do this in a pressure canner if I add peppers onions and basil w salt or should I use lemon juice
How do I keep seeds for planting next yearThank you
Kelly August 20, 2021 Reply
Hi Lori!
When you can various foods together, you always want to process for the longest time required for any of the items. Onions require the longest time pressure canning so although you add other ingredients, like tomatoes and peppers, process by following directions for canning onions.
Here are instructions from Clemson University: https://www.clemson.edu/extension/food/canning/canning-tips/31preserving-onions-garlic.html
Also, I’m glad to hear that you want to save your seeds, here’s how to do that!
https://www.gentlysustainable.com/saving-heirloom-tomato-seeds/Thanks for your question, I hope I helped!
Ellis August 20, 2021 Reply
I have a question, I am new to canning. We decided to juice the tomatoes instead of dicing them. Did not cook them first but put the juice in sterilized jars after separating in the juicer with lemon juice and salt. We processed the jars for 45 minutes. Can the juice be salvaged or is it ruined?
Kelly August 21, 2021 Reply
Hi Ellis!
Welcome to the exciting world of canning your own food! I’ve been canning for decades and I’m still learning new things and making mistakes now and then. So don’t be too hard on yourself, it happens to the best of us.
You didn’t mention whether you used a water-bath or pressure canner, however, the processing time wasn’t the problem with your tomato juice.
According to the “Ball Complete Book of Home Preserving”, it’s important to boil the tomato juice, for 10 minutes, before you put it in the jars. (I highly recommend this book! https://amzn.to/2Wh4IQY )
Quoting the book “It is very important that you reheat the tomato juice before filling the jars. Processing times are based on hot juice in a hot jar. If the juice is tepid, the processing time won’t be sufficient to vent the excess headspace gases and/or destroy spoilage microorganisms.”
For safety sake, I would pitch the juice and consider it lesson learned.
Thanks for the great question!
Ellis August 21, 2021 Reply
Thank you so much! Not the answer I was hoping for. Lesson learned
Laurie August 25, 2021 Reply
Thank you so much. Dumb question, when you say cover the jars by 1-2”, are you meaning completely under water or 1-2 “ from the bottom?
Thanks, new to this😀
Kelly August 25, 2021 Reply
Hi Laurie!
Great question! You learn by asking, so never be afraid to as your questions!
So, the jars should have 1-2″ of water covering them/above them in the canner.
Once the jars are ready and in the canner (the canner will already have water in it, you’re going to add to that), you’ll add water to the canner until it’s covering the jars with 2″ of water.
This is so that the hot water can completely circulate around the jar to process the food.
Does that help? If not, I’ll think of another way to put it.
Tomi August 27, 2021 Reply
Hi Kelly, I misread your instructions and processed my 1/2 pint jars with the water not covering over the lids. 10 of the 12 jars sealed. Will they be okay and of not, is it possible to reprocess them all again?
Kelly August 27, 2021 Reply
Hi Tomi,
Don’t feel bad, it happens to all of us.
However, it’s important that the water cover the jars by 1-2″ so that the hot water surrounds the jar with water hot enough to kill pathogens. Lids sealing doesn’t indicate the food’s safety.
There are varying opinions about reprocessing food.
Some will say that you can reprocess safely if discovered within 24 hours, but I don’t think I would.
I will always lean on the side of safety, a batch of tomatoes just isn’t worth the risk of botulism.
If it were me, and I discovered the mistake within the 24 hour period, I would just make a recipe with lots of tomatoes and use them up right away.
They could keep in the frig for 2-3 days, if discovered in the 24 hour period. You could also freeze them within the 24 hours.
I hope that helps!
Natalie Corneau August 26, 2021 Reply
Hello Kelly,
I noticed you didn’t peel the skins off the tomatoes before dicing them. Does it make a difference?
My cherry tomato plants went nuts this summer so I will be canning those. I really don’t want to peel them! Haha.
NatalieKelly August 26, 2021 Reply
Hey Natalie,
When I first started to can, I was taught to remove the skins from the tomatoes. Frankly, I just didn’t think it was a necessary step, plus it added a lot of work to the process.
The skin doesn’t bother me, it adds fiber and so I leave it on. But it’s just a matter of preference.
You could can your cherry tomatoes by just cutting them in half to remove the seeds and then process. You might find that you don’t mind the skin either!
Great question!
Mike August 26, 2021 Reply
Can I use a pressure canner?
Kelly August 26, 2021 Reply
Hi Mike! You can absolutely use a pressure canner for tomatoes and the processing time will be much shorter, preserving more nutritional value! Check your canning book for times.
Great question!
Barb August 27, 2021 Reply
I have diced tomatoes that I’m canning and have to go somewhere, so can I leave them until tomorrow and if so, do I need to refrigerate them
Kelly August 27, 2021 Reply
Hi Barb!
You didn’t mention what stage of the process you’re in, however I would empty all of your tomatoes into a bowl, cover it and put in frig.
When you get back to your canning, make sure that your jars are clean (again) and resume canning.
Sylvia Rossi September 1, 2021 Reply
Appreciate your straightforward explanations. I’ve canned with others but this is my first garden and canning on my own. I am reading everything I can get my eyes on!
I just wanted to relate an experience a friend had while water bath canning, which she’s done for years. She had a glass cooktop, similar to the one pictured and the top cracked and broke while she was processing!! Yikes! I purchased a new canning kettle this past week and it now states on the label not to use it on a glass cooktop. Have you heard this before? Take care!Kelly September 1, 2021 Reply
Hi Sylvia!
Congrats on your first garden!! That’s so awesome that you’re canning as well!
Yep, I’ve heard the same thing about glass tops.
While I’m sure that with enough pressure, any glass top stove could crack and break. And, like you, I’ve heard stories about that happening.
However, this is the second glass stove I’ve owned and canned on. I’ve never had a problem.
I’m careful to slide my pots off and on.
One day, I would love to have a natural gas stove, but for now, it’s just not in the cards. I’m using what I have and committing common sense to my canning.
I hope that answers your question!
Sylvia September 1, 2021 Reply
Kelly, so glad you’ve not had any issue! First I had heard of this was when it happened to my friend, she was so disappointed! I’d be lost if I weren’t cooking with a gas stovetop. I’ve made caramels at Christmas time for decades and the only batch I’ve ever ruined were on an electric stove. Thanks again for your concise directions! Will be doing my sauce tomorrow! Take care!
MARGIE September 4, 2021 Reply
DO YOU LEAVE THE RINGS ON THE JARS AFTER THEY HAVE COOLED AND YOU ARE PUTTING THEM IN YOU PANTRY…IF SO WHY?. I RAN OUT AND HAVE BEEN STEALING THEM TO PUT UP MORE TOMATOES 🍅.
Kelly September 4, 2021 Reply
Hey Margie!
Once the lids have sealed, the rings have no further purpose. You can feel comfortable removing them and using them again for other jars that you’re canning.
That said, if I don’t need the rings for another batch of canning, I just leave them on the jars. It’s just easier than finding a place to store all of the rings.
I hope that answers your question!
Kelly
Donna August 9, 2022 Reply
I just read on someone else’s blog that canning diced tomatoes is not recommended because of the thickness in the jar won’t heat through properly. They recommend crushed tomatoes. I use diced tomatoes the most in recipes and really hope I can do so safely!
Kelly August 11, 2022 Reply
Hi Donna,
Your question got me thinking, because I can diced tomatoes as well. After a great deal of research on the Ball website and the NCHMP, to make sure there wasn’t any new data that I wasn’t aware of, it seems that the only issue with canning diced tomatoes is that they are more prone to shrinkage during the canning process, leaving a gap at the top of the jars. For that reason, it is recommended that diced tomatoes are processed using the “hot pack” method, which means boiling the diced tomatoes for 5 minutes before loading the jars. There doesn’t seem to be any safety issue, that I can find. I prefer raw pack to preserve the nutritional value and I don’t mind some gap in my jar. Great question!
Sharon August 26, 2022 Reply
Is there a printable version of this receipe?
Kelly August 26, 2022 Reply
Yes, ma’am! I just added a “Print” to all of my posts! See what you think!
JJ August 29, 2022 Reply
My Ball canning book instructions for raw pack tomatoes using the water bath method requires 85 minutes processing/boiling time. Which time is correct…45 minutes or 85 minutes?
Kelly August 30, 2022 Reply
Hi JJ! I think where the confusion lies is with the liquid you’re canning tomatoes with. When canned with water, like this post explains, the times are 40 min for pints/45 minutes for quarts. However, when canned with their own juice, the time jumps to 85 minutes. Great question, I hope this clears things up!
Tammy Dudman June 25, 2023 Reply
Hi… I’m going to try canning some tomatoes this year for the 1st time. I am wanting to add some onion to my jars of tomatoes. And do them in a water bath. If I do this how much time will I need to add to the 40-45 minutes?
Kelly Morris June 25, 2023 Reply
Hi Tammy! Onions are a low-acid food and must be pressure-canned. While you can pressure-can tomatoes, the quality is compromised. Might I suggest dehydrating or freezing the onions? It’s a lot easier.
Coty October 22, 2023 Reply
Hi! We didn’t have many tomatoes and we didn’t have the right size jars. Oh well, it’s our first time canning tomatoes! We literally got 1 jar. ONE. We’re happy we did it though as it was a good lesson. One thing though. Our tomatoes were pretty mushy after blanching them. Can you tell us what the reason is for that? Still, it’s a pretty jar and we’re proud!! Thanks for the recipe.
Susan March 15, 2024 Reply
What is the shelf life of canned tomatoes in pressure canning versus water bath canning?
Kelly Morris March 17, 2024 Reply
To my knowledge, there is no difference in shelf life. The quality of the seal and the way the jars are stored determines the shelf life.
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