40 F - 140 F

Discussion in 'Food & Cooking' started by deltadoc, Jan 4, 2005.

  1. deltadoc

    deltadoc

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    The above temperature range is the range that food should not be left at for more than 2 hours.

    For instance, when the stock is finished, one is advised to use a cooling bath to reduce the temperature quickly before refrigerating.

    So, this may be an ignorant question, but here goes anyway!

    So why is it ok to make creme fraiche for up to 72 hours at room temperature?

    The recipe I use is 3 C Heavy Cream + 1 C Buttermilk, left loosely covered at room temperature for up to 3 days. It smells and tastes just fine, and we've never gotten sick from eating it.

    Just curious, and am looking forward to a knowledgeable answer from someone.

    Thanks,
    doc
     
  2. suzanne

    suzanne

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    In a word: acidity.

    In a few more words: there are regulations, and then there is cooking. Just don't let your local health department see you feeding that stuff to a paying customer. :p

    Forgive me for being facetious, but . . . . :rolleyes:
     
  3. phatch

    phatch Moderator Staff Member

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    Most foods left in the danger zone are in some sort of active culturing. Bread with its yeast, creme fraiche and so on.

    These cultivated cultures will outcompete the dangerous ones for a while, thus the timing and observation that are important to this sort of prep.

    Phil
     
  4. keeperofthegood

    keeperofthegood

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    Hey oh

    I also understand that there are natural toxins that variouse bacteria release to prevent other bacteria from competing. So, a yeast will also be fending off anything that is non-yeast, adding a measure of secruity in room temp preperations.

    I could be wrong on this though. Anyone?
     
  5. kuan

    kuan Moderator Staff Member

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    The strong will push out the weak. In this case it's live culture lactobacillus acidophilus. There may be "toxins" but it's mostly acid and it really doesn't matter anyway because the high concentration of lactobacillus pushes out any competition which may be trying to gain a toehold. When the acid level gets too high the lactobacillus will die, or in the case of commercial creme fraiche, it's pasteurized. Pasteurized craime fraiche actually spoils more easily because of the lack of live culture. Craime fraiche made with pasteurized cream which has been innoculated keeps longer. Just like sour cream. :)