Friday, February 15, 2008

Home-Canned Tomatoes Linked to Botulism

The International Society for Infectious Diseases reported today that 14 people were hospitalized due to botulism recently in the Yugra district of Russia after participating in a "feast" on February 3rd. One of the victims died. Preliminary investigation results are pointing to home-canned tomatoes as the source of the illness.

This is a reminder that even relatively acid canned foods, such as tomatoes, can be a source of botulism. Boiling temperatures will inactivate the toxins produced by Clostridium botulinum. If you home-can, please reheat the canned food to the boiling point and allow it to simmer for at least 10 minutes before tasting even a tiny amount of the food.


  1. Hey Bug-Lady! It's Bag Lady again!

    I do a lot of home-canning, and try my damnedest to follow all the rules. Botulism is something I worry about constantly.

    You recommend re-heating the food after you open the jars, did I read that right? (boil for 10 minutes?)
    I have limited my tomato canning the past couple of years to salsa, pizza sauce and plain canned tomatoes. I always add lemon juice for acidity, except to the salsa, which has apple cider vinegar in it.
    And I always process my tomato products in a hot-water bath for the recommended time.

    If the jars seem to have a really good seal, am I still playing Russian Roulette by not re-heating my salsa before I eat it?

  2. Hi Bag-Lady and welcome back.

    The only thing we ever preserve is jams. The high sugar content (and resulting low water activity) keeps things safe.

    The key to avoiding botulism is proper pH control. If the pH of your salsa, sauce or tomatoes is 4.5 or lower, you don't have to worry. Personally, I wouldn't rely simply on adding lemon juice or vinegar, because the tomatoes can vary in their natural acidity.

    To be safe, only preserve vegetables that you will reheat before eating. Otherwise, Russian Roulette is going to be a permanent game in your household.


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