Canning Tomato Soup Base {Homemade Canned Tomato Soup}

Follow this step-by-step tutorial to learn how easy Canning Tomato Soup can be. The ultimate comfort food, this tomato soup base recipe can be pressure canned or preserved via water bath canning. 

Homemade tomato soup is amazing and tastes so fresh, but peeling and pureeing tomatoes each time you want soup is super time-consuming. Not to mention that tomato season is only about six weeks long here.

So what is a soup-obsessed girl to do? Can her own tomato soup base, of course. Let’s do this!

Which Tomatoes Are Best For Canning Tomato Soup?

Easy answer – whatever tomatoes you have! Paste-style tomatoes are thicker and have fewer seeds, but their flavor is not usually very exciting.

Throughout the growing season, I’m busy canning (whole) tomatoes and canning stewed tomatoes, but I save canning tomato soup for the end of the season when all that is left are the random tomatoes. Random tomatoes make the best soup because you get all the complex amazing tomatoey flavor in one delicious bowl.

You need about 45 pounds of tomatoes for 14 pints or 7 quarts. Since I never have that many at once, I do small batch canning and might produce 1-4 quarts at a time. It all adds up and it all eats the same.

Pro tip: if you grow your own tomatoes and don’t have enough to can at once, you can freeze them on baking trays and then transfer them to freezer bags (I love these reusable silicone bags) until you have a critical mass for canning.

Why Do I Need Bottled Lemon Juice?

The lemon juice is needed to regulate the acidity of the tomatoes to keep the pH level consistent. Storebought lemon juice generally has the same level of acidity (5%) from bottle to bottle. You don’t get that guarantee with freshly squeezed lemons. 

How to Can Tomato Soup (Pressure Can) – Step by Step

I’ll walk you through the process here in photos because it really helps, especially if you’re new to canning. At the bottom of the post, you’ll also find a printable and detailed recipe card.

Rinse all your awesome tomatoes and cut them in half. If you have big ol’ hunkers, then cut them into smaller chunks. Add a strainer/colander to a large bowl.

Wash and clean your jars. For canning soup, I recommend quart-sized regular mouth jars. It is no longer necessary to sterilize jars before canning (hurray!) but you should make sure they are preheated enough to not crack when placed in hot water.

You can put them in a clean dishwasher and run them through a quick wash cycle, or place them in a large pan with some water in a low heat oven (my lowest temp is 170 degrees) until you need them. I’ve even just put hot tap water in them before and left them on the counter.

Wash your lids with hot soapy water and place them in a clean bowl for now.

Add the tomatoes to a pot of boiling water and parboil them until you see the skins start to come off one of the tomatoes (about 1-2 minutes). You can read a more in-depth tutorial on How to Blanch and Peel Tomatoes.

Use a slotted spoon and remove the tomatoes and place in the strainer.

Run the tomatoes through a food mill to remove the seeds and skins. If my tomatoes are particularly watery, I will strain them a bit through a mesh strainer. 

Pro tip: when you have a bowl completely full of skins and seeds, run them through the food mill two more times. I always get almost an extra quart out of these scraps.

Transfer the tomato puree to a pot over low heat or a crockpot set to low. Keep warm until ready to can.

Add 3 quarts of water to your canner and put it on a burner set to high. Make sure there is a canning rack in the bottom of the canner. (Reminder: these are pressure canning instructions. See the recipe card for water bath canning details).

Place a funnel on a canning jar, add the lemon juice or citric acid, and ladle in the warm tomato puree, leaving 1 inch of headspace. Headspace is defined as the space between the top of the soup and the top of the jar. Remove any bubbles from the jar (I use a plastic chopstick).

Use a wet clean rag and wipe the rim of the jars to make sure they are free of any food.

Place a clean lid and then a ring on the jar and tighten the ring to fingertip tight (tight enough that it won’t come off, but not so tight that the Hulk couldn’t budge it).

Place the jars in the canner. If you don’t have enough jars to fill the canner, consider Canning Water in a few jars to stock your emergency drinking water supplies.

Lock the lid. Soon, steam will start coming through the vent pipe (I call it the steam chimney). Allow the steam to pass through for about 10 minutes. Then put the pressure regulator (I call it the chimney cap) on top.

Pretty soon, the air vent will pop up. That is a sign that you’re starting to build pressure inside the canner.

Under normal conditions, tomato soup needs to be pressure canned at 11 pounds of pressure for 15 minutes for both pints and quarts. See chart below for any changes to processing times.

When the dial gauge reaches the appropriate PSI, reduce the burner temp to medium, and start your timer. The pressure must stay at the PSA or (a little bit) above for the duration of the cooking time.  You’ll likely need to adjust the temp on the burner a few times depending on your stove.

When the time is up, remove the canner from the burner and allow it to sit until you hear a distinctive “click” of the air vent dropping. Remove the pressure regulator and carefully remove the lid of the canner (Pro tip: I always use oven mitts when I take the lid off because the steam is super hot).

Let the jars sit for 5 minutes in the canner and then lift them out with canning tongs. Place them on a towel where they can sit undisturbed for 12 hours.

After a few hours, to check for sealing, gently press down in the middle of the lid. If the lid has no give, it’s sealed. If you can press the lid in and it pops a bit, your jars are not sealed. You can reprocess them or store them in the fridge or freezer (only freeze jars that are wide-mouth). Store in a cool dry place for up to 12 months.

How to Can Tomato Soup {Water Bath Canning}

Follow all the steps above for blanching, making, and jarring the tomato soup base.

Prepare your water bath canner by filling it with water. You need to have enough water to cover the jars by 1 inch once the water is boiling.

Set the canner on the stove. Turn the burner to high.

Wash and clean your jars. You’ll want to keep them warm to avoid having them crack when placed in the canner. You can fill them with hot water, or place them on a tray in the oven at 170˚F.

Wash your lids and set them aside in a clean place. You no longer need to simmer lids in water to keep them sterile. Woot!

Using canning tongs, carefully place your jars in the canner. Put the lid on. Processing times will vary based on altitude. See the chart below. Pro tip: the water must return to a boil in the canner before you can start the timer.

Once the jars have been processed for the appropriate amount of time, remove the canner from the burner, wearing oven mitts carefully take off the lid of the canner, and allow it to sit for 5 minutes. Pro tip: I tend to just slide the canner into the middle of my stove, as it weighs a ton.

Carefully remove the jars with canning tongs, and place them on a thick towel in a place where they can be undisturbed for 12 hours.

HELP! WHY ARE MY JARS LEAKING Tomato JUICE?

If you find that juice has leaked out after they have sealed, you have experienced a common canning issue called siphoning. It happens to the best of us!

Siphoning is typically caused by not allowing the jars to rest in the canner after they have finished processing. In the directions, you’ll see that I recommend you remove the canner from the burner, remove the lid, and let it sit for 5 minutes.

This is important as it allows the jars time to rest before being allowed to cool on the counter. Doing this process will significantly cut down on siphoning.

IF YOU HAVE SIPHONING IN YOUR JARS, FOLLOW THESE STEPS:

• Check – are the lids still sealed?
• Look – have you lost less than half of the amount of liquid in the jar?
• Examine – does the tomato sauce still look fresh with bright colors?

If the answer to the above three steps is “yes!”, then they are safe to eat.

Why Do I Need to Remove All the Seeds and Skins?

Gosh, it would be so much easier to just blend the tomatoes whole, right? Technically you don’t need to remove the seeds and skin, but I find too many seeds will turn your soup completely bitter; what a waste. Skins can also give your final product a weird texture and throw off the taste.

If you’re in a rush, canning whole tomatoes might be more up your alley. And they’re super versatile and easy to use in soups and stews. Or you could even dehydrate tomatoes.