• Skip to primary navigation
  • Skip to main content
  • Skip to primary sidebar

Urban Overalls

Country Living in a City Setting

  • Home
  • Life on the Homestead
    • Homestead How-Tos
  • All Creatures
    • Chickens
  • Homestead Recipes
    • Preserving
  • Gardening
    • Vegetables
  • A Little About Us
  • Contact Us

Tomatoes: What Not to Can

Share on pinterest
Pinterest
Share on facebook
Facebook
Share on twitter
Twitter
Share on stumbleupon
Stumbleupon
Share on yummly
Yummly

It is that time of year where tomatoes are abundant.  Perhaps you are growing them in your garden?  Or perhaps you find them by the case at your local farmer’s market? But regardless of where they come from, do you know which tomatoes to avoid for canning purposes?

According to NCHFP, “Select only disease-free, preferably vine-ripened, firm fruit for canning”.  That sounds easy right?  But what if you harvest or buy tomatoes that don’t look picture perfect?

Iowa State University Extension and Outreach offers a little more information with this statement: “Overripe and infected tomatoes may be low enough in acid to support Clostridium botulinum.  Use only firm, ripe tomatoes that have no spoiled parts or mold.  Tomatoes harvested from dead vines are low in acid.  They can be eaten fresh or frozen, but do not can tomatoes from dead vines”.

To give you a better understanding of which tomatoes to skip when it comes to canning, a photo is worth a thousand words (or at the very least a photo with a brief description).

urbanoveralls.netanthracnose infected tomato

Anthracnose is a tomato disease (fungus).  Symptoms of this appear on ripe fruit, starting as small, sunken, and water-soaked lesions.  These lesions will then increase in size and the center will darken (and contain a fungal structure from which spores are released) and the tomato begins to soften.

urbanoveralls.netinternal black mold

Internal black mold may be caused by a couple of diseases.  The first is anthracnose as listed above.  The second culprit could be blossom end rot.  Mold may simply enter through hole (caused by animal or insect) or a crack in the tomato skin.  If you purchase tomato ‘seconds’ at a market or farm or using ones from your own garden that appear to have some damage, it is prudent to cut open the tomato to make sure the tomato does not have internal black mold like the one in the photo above.  Sunscale may also cause internal black mold, though in this case, the damaged tomato is allowed to stay on the plant too long and the tomato begins to rot.

Sunscald.  Now with this issue, the tomato itself is exposed to direct sunlight during periods of hot weather.  If the damage is just a tan, papery blemish, that can be cut away.  However, if the affected tomato is allowed to stay on the vine, internal mold may develop.

Tomatoes that have an off aroma should not be used.  A healthy tomato should smell like… well… a tomato.  If the fruit smells sour or moldy (even if mold is not visible), discard the tomato.

Diseased tomatoes and those with internal black mold should not be used for canning purposes.  The act of canning will not remove the disease or repair the mold.  These tomatoes could spoil in the jar and ruin your batch regardless if you canned them for juice, stew tomatoes, or even pasta sauce.

For the best possible canning results, use vine-ripened fruit that is firm to the touch.  As the saying goes, “If in doubt, toss it out” should apply when it comes to this summertime fruit.   So keep in mind, what not to can when it comes to tomatoes.  Your health will thank you for it.

Share on pinterest
Pinterest
Share on facebook
Facebook
Share on twitter
Twitter
Share on stumbleupon
Stumbleupon
Share on yummly
Yummly

Filed Under: Gardening, Insects/Disease, Preserving

Reader Interactions

Comments

  1. Robbie says

    October 1, 2014 at 9:57 am

    now that is something I never knew–thank you for sharing:-) I won’t feel guility throwing them away!

    Reply
    • urbanoveralls says

      October 1, 2014 at 11:49 am

      You are welcome. While we all want to use as much of our harvested or purchased produce as possible, sometimes the best thing we can do is toss out the ones with an off aroma or are diseased.

      Reply
      • Robbie says

        October 1, 2014 at 11:55 am

        I think you are wise + I am glad you wrote about this

        Reply
        • urbanoveralls says

          October 1, 2014 at 3:54 pm

          Oh.. thank you. I felt that this is something that not everyone knows about.

          Reply
  2. Vickie says

    October 1, 2014 at 11:45 am

    This makes a lot of sense. Thanks!

    Reply
    • urbanoveralls says

      October 1, 2014 at 12:18 pm

      You are welcome. Sometimes I think we feel compelled to use everything when in reality, we are better off just tossing some of the produce.

      Reply
  3. Sue Dreamwalker says

    October 1, 2014 at 3:20 pm

    I have never experienced internal black mould.. I have had several split this year with lines running around the top.. Which I have cut away and used these tomatoes for fresh soup making.. in fact I made fresh tomato soup today… I add a a Red or green pepper in too.. ( not the hot variety ).. Roast them in quarters in the oven then blend in blender with veg stock.. delicious 🙂 Thank you for this post.. 🙂

    Reply
    • urbanoveralls says

      October 1, 2014 at 3:56 pm

      This year, I bought cases of tomatoes as ours (in the garden) have been slow to ripen. This is the first time that I encountered it, but knew that mold could develop from various tomato diseases. (Your soup sounds wonderful).

      Reply
      • Sue Dreamwalker says

        October 1, 2014 at 4:02 pm

        It is… and nice and you make it as thick or thin as you like it by just adding more or less veggie stock.. .. My recipe is here if you are interested.. I add just one pepper sliced and roasted and around 3 to 4 gloves of garlic depending on size… Enjoy
        https://urbanoveralls.net//suedreamwalker.wordpress.com/recipes/roasted-tomato-soup/

        Reply
        • urbanoveralls says

          October 2, 2014 at 10:44 am

          Oh… thank you for the link to the recipe. We love tomato soup and we turn it into a childhood favorite by making grilled cheese sandwiches to go along with it.

          Reply
          • Sue Dreamwalker says

            October 3, 2014 at 9:08 am

            Great Minds think alike.. Me too 🙂

          • urbanoveralls says

            October 3, 2014 at 9:33 am

            🙂

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

Primary Sidebar

Welcome to Urban Overalls

I’m Connie. Growing up on a farm in rural Iowa taught me me many lessons: raising chickens, growing produce, enjoying raw milk, how to cook from scratch using whole foods, canning, mending clothes, and the importance of being someone who gives back to the community.

Now, living in an urban setting, I brought my country ways with me. Join us as Mr. Overalls and I share our adventures, recipes, and how-to in our daily lives on our 1/3 acre slice of heaven near the center of town.

Follow Us

Can I help you find something?

New Articles

pure coconut oil soap fb | urbanoveralls.net

Pure Coconut Oil Soap

cracklins in liquid lard

Small Batch Lard Rendering

orange bell peppers

Jack O' Lantern Stuffed Bell Peppers

green pork chile

Homemade Green Pork Chile

Readers Favorites

Getting Started with Package Bees

Crave-worthy Caponata

Free-Range Chickens: New Method or Remake of an Old Classic?

Urban Chickens: Should we Worry about Salmonella?

  • All Creatures
  • Gardening
  • Homestead Recipes
  • Homestead How-Tos
  • Life on the Homestead

Copyright © 2025 · Genesis Sample on Genesis Framework · WordPress · Log in