Botulism baby!

Discussion in 'Open Forum With Harold McGee' started by chrose, Dec 10, 2005.

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  1. chrose

    chrose

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    Mr. McGee. There have been several threads over the course of time about the safety of both canning home items, and homemade flavored oils. I have found a couple of links to scientists that make me feel a little better about what I make, but everytime I either can something or flavor an oil somewhere in the back of my mind I wonder if I'm going to kill my family:eek:
    There is so much technical information out there, I have one more herculean task to ask you. Can you boil your knowledge down to a couple of simple rules to follow pertaining to either oils or canning that the general populace can follow?
    Secondly, what about flavored vinegars, because of the acidity of vinegar how do the rules of canning and oils apply to them?

    Thanks again.
     
  2. harold mcgee

    harold mcgee

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    The basic thing to keep in mind is that botulism bacteria thrive in warm, non-acid, oxygen-free conditions, and their seed-like spores can only be reliably destroyed by prolonged boiling or at pressure-cooker temperatures. Canning and steeping foods in oil are risky because they provide protection from oxygen. Foods that aren’t distinctly sour need to be either acidified, heat-sterilized, or kept refrigerated or frozen. The acetic acid in vinegar is strong enough to inhibit the growth of botulism bacteria, so flavored vinegars don’t require special anti-botulism treatment.

    Harold
     
  3. markv

    markv

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    Mr. McGee:

    Let me first say your book is fantastic. The bible of food science for sure.

    About the flavored oils.................

    I assume you're safe from botulism when making a flavored oil if you use it up right away?

    There's only a danger if you're going to store it for some time correct?

    Mark
     
  4. harold mcgee

    harold mcgee

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    Thank you, Mark. No, even making the oil can cause problems: botulism bacteria can multiply and produce toxin in a matter of hours, if the conditions are right (warm temperature, nutritious material under oil).

    Harold
     
  5. markv

    markv

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    Well you've really given me food for thought.

    I regularly make hot chile oil. I take a bunch of dried chiles, grind them, bring them to a very gentle simmer in olive oil, allow the entire coccotion to cool, and then store it in the fridge. One batch will last me a couple months.

    It sounds like I'm taking a risk, yes?

    Mark
     
  6. praties

    praties

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    Good questions, Chrose and Mark. I always figured short-term use flavored oils were all right. I never realized botulism can multiply that quickly!

    Praties
     
  7. harold mcgee

    harold mcgee

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    No Mark, your chilli oil is fine, for several reasons. First, because the chillis are dry—and bacteria need moisture to grow. The simmer also guarantees that any remaining traces of moisture are cooked out. Finally, storing the oil in the fridge slows the growth of any surviving bacteria to a crawl.

    Harold
     
  8. markv

    markv

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    Thank you Mr. McGee for your response.

    Now I can enjoy my chile oil with peace of mind.

    Mark
     
  9. nicko

    nicko Founder of Cheftalk.com Staff Member

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