Follow this step by step tutorial to learn all about Canning Tomato Soup. This tomato soup base recipe can be pressure canned or via water bath canning.
Rinse all your awesome tomatoes and cut in half. If you have big ol' hunkers, then cut them into smaller chunks. Add a strainer/colander to a large bowl.
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.
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).
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.
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 pressure canner and put it on a burner set to high. Make sure there is a canning rack in the bottom of the canner.
Place a funnel on a canning jar, add the lemon juice, and ladle in the warm tomato puree, leaving 1 inch of headspace. Headspace is defined as the space between the top of the food and the top of the jar. Remove the bubbles from the jar (I use a 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 on the jar and tighten the ring to fingertip tight.
Using canning tongs, gently place the jars in the canner. Lock the lid. Soon, steam will start coming through the vent pipe. Allow the steam to pass through for about 10 minutes. Then put the pressure regulator on top. (see photos in post above to see this in action)
When the dial gauge reaches 11 pounds of pressure, reduce the burner temp to medium, and start your timer for 15 minutes. The pressure must stay at 11 or a bit above for the next 15 minutes. 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 (Pro tip: I always use oven mitts when I take the lid off because the steam is crazy hot).
Let the jars sit for 5 minutes in the canner and then lift them out with canning tongs. Place 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).
Complete steps 1-7 above.
Fill your canner so that there will be 2 inches of water over the tallest jar that you are canning. Set it on a large burner set to high.
Complete steps 9-11 above
When the water has reached a rolling boil, place the jars in the canner and place the lid on top. Process pints for 35 minutes or quarts for 40 minutes.
When the time is up, remove the canner from the burner and let the jars sit for 5 minutes in the canner and then lift them out with canning tongs. Place on a towel where they can sit undisturbed for 12 hours.
Typically, 45 pounds of tomatoes will make 14 pints of 7 quarts of tomato soup.
2 tbsp of bottled lemon juice per quart or 1 tbsp per pint. You can also use 1/4 tsp (for quarts or pints) of citric acid.
Store in a cool dry place for up to 12 months.