Canning 101: Home Canned Tomatoes

The following is a guest post from Marisa of Food in Jars. Welcome, Marisa!

Canned tomatoes are a pantry staple. However for most of us, our tomatoes come in cans from the grocery store. For a moment though, imagine what it would be like to have a pantry lined with sparkling glass jars, filled with home canned tomatoes.

It’s far easier than you might think!

What you’ll need for four quarts of tomatoes:

  • A large stockpot (for processing the jars)
  • A small, round rack (to keep the jars off the bottom of the pot)
  • A smaller pot (for blanching the tomatoes)
  • A tiny saucepan for simmering lids
  • A kettle for boiling water
  • 4 clean quart jars, new lids and rings
  • A paring knife
  • Jarred lemon juice
  • A tablespoon measure
  • 25 Roma tomatoes
  • Boiling water

How to can tomatoes:

1.    Place the rack in the bottom of your stockpot. Make sure to choose a pot that will allow the jars to be submerged with at least one inch of water above them and some room still at the top of the pot to allow for boiling.
2.    Fill the pot with water and begin to bring to a boil.
3.    Fill your smaller blanching pot with water and bring to a boil.
4.    Fill the kettle with water and bring to a boil (yes, there’s lots of water boiling in canning).
5.    Place lids in the smallest pot and bring to a very low simmer.

All photos by Marisa McClellan

6.    While waiting for the blanching water to boil, remove the cores from the tomatoes and carve a small cross into bottoms of the tomatoes, to make them easier to peel post blanching.
7.    Once the smaller pot of water has come a boil, blanch the tomatoes in batches of 3 or 4 (keep the batches small so that you don’t drop the water temperature too drastically) for 1-2 minutes. Use a slotted spoon to remove the tomatoes from the blanching water.
8.    When tomatoes are cool enough to handle, peel them. You should be able to do this with your hands, but keep that paring knife close for the troublesome spots.
9.    Once you have 6 peeled tomatoes, you can fill a jar. If you’re using regular mouthed jars, keep a wooden spoon around, to help you pack the tomatoes into the jars. You should be able to get 5-6 tomatoes into each jar without too much squishing. We’re making whole tomatoes in water here, so do your best not to smash them too much.
10.    Keep peeling and filling jars, until you have four filled jars lined up on your countertop.

11.    Add two tablespoons of lemon juice to each jar.
12.    Top each jar off with the boiling water from the kettle, leaving ½ inch of headspace in each jar.
13.    Using the end of your wooden spoon, remove any air bubbles from inside the jars. Add a bit more water if necessary.
14.    Using a clean kitchen towel or a bit of paper towel, wipe down the rims of the jars.
15.    Place lids on the jars and apply the rings to the jars (don’t tighten those rings too much).
16.    Using jar lifters or tongs (take care when using tongs, it’s easy to give yourself a boiling water burn with them), gently lower the jars into the canning pot. You may need to remove some water, a 2-cup pyrex measuring cup does this task well.
17.    Once all the jars are in the processing pot, put a lid on it and bring it back up to a boil. Adjust the burner temperature to keep the pot boiling gently. Process for 45 minutes.
18.    When the time is up, remove the jars from the pot. Place them on a towel-lined countertop and allow them to cool. The lids should audibly ping as they seal.

Once the jars are completely cool, remove the rings and test the seal by gently tapping the lid. It should hold tight and be concave.

And you’re done! Four quarts of gorgeous, home canned tomatoes are ready for your pantry shelves.

If whole canned tomatoes aren’t really your thing, that doesn’t mean you should rule out home canned tomatoes entirely. Consider salsa, sauce or juice for a start.

Happy canning!

Questions? Pointers? Feel free to discuss in the comments section below.

About Marisa

Marisa McClellan is a food writer, canning teacher, and dedicated small batch canner who lives in Center City Philadelphia. Find more of her jams, pickles and preserves (all cooked up in her 80-square-foot kitchen) at her blog, Food in Jars. Her first book, titled Food in Jars: Preserving in Small Batches Year-Round, is now available.

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Comments

  1. Susan Metcalf says:

    Just canned tomatoes and a couple seals look “buckled” a bit – is that a poor seal or just too hot for too long? I water bathed for 45 mins/pints. Appreciate your comments

  2. Hi. I tried to can 8 pints of tomatoes today. I filled them within a half inch of the top and placed them in a pot of boiling water with an inch of boiling water on top. 4 out of the 8 mason jars broke. My mom mentionned afterwards that she always poured the boiling water over the jars. Very disappointing.

    • Hi Debbie, that is a bummer!

      it sounds like your jars either were defective or they underwent thermal shock and that caused them to break. This can happen if you allow the filled jars to cool down before you put them in a a boiling water bath.

      If you let your jars of product cool, you have to also let your water bath cool. Add cold water to the bath if necessary to cool it down. After adding the cooled jars to the cooled water bath, bring the bath up to a rolling boil and start counting your processing time from then.

      Also, when you remove the hot jars from the bath after processing, be sure to place them on a clean, dry and insulating surface, like a clean dry towel, so the jar bottoms don’t come into contact with something cold. Sudden heating or cooling will cause uneven expansion or contraction of the glass and cause it to shatter.

      Personally I would not use your mom’s method because pouring that much boiling water from one vessel to another is to difficult and dangerous for me. Your mom must be one strong lady!

      Any way you do it, you have to make sure that the contents of the jars are at about the same temperature as the water in the processing bath when you add the jars to the bath. Then bring it to a boil, then start counting your minutes.

      Good luck with your next canning project!

  3. Rhea Lawson says:

    My mother used to make, what she called soup mix. She would use fresh tomatoes, corn, lima beans and green beans. Not sure the measurements, but it was mostly tomatoes. She said the tomatoes had enough acid in them to keep the other ingredients from spoiling. She would process in a water bath for 45 minutes. We ate that soup mix all winter and we never were sick. This was in the late 50’s early 60’s. It was pretty in the jars as well!

  4. Hi. I’m canning tomatoes for the first time and was was wondering how soon after blanching and peeling must the tomatoes be canned? Can I peel then can the next day?

    • I would not recommended doing it that way. You have done all the hard work by peeling them, take a few minutes more and put them in the jars and covering them with water but without sealing them with the new lids.

      If you have to wait until the next day for some reason to process them, be sure to put the jars in the refrigerator. [also the next day the jars will be very cold so start your water bath with cold water so both items are basically the same temperature to prevent breakage because of extreme temperature difference.]

  5. Do you have to heat tomato juice before pressure canning
    Thanks

  6. lou child says:

    what do I need to do if I didn’t cook my tomatoes long enough

    • You can put them back in the hot water for another minute or two or just peel them with your paring knife. Roma tomatoes take a little longer.

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