Meat thermometers reading too high

Discussion in 'Food & Cooking' started by thefsb, Dec 25, 2013.

  1. thefsb

    thefsb

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    Over the years I have used standard instant-thermometers with good results. In the summer I got a couple of digital units (Polder and Maverick) with remote probe that you can insert before putting the meat in the oven. Every attempt to use these digital devices has been frustrating. They consistently read too high and I don't understand why.

    I have checked calibration against boiling water and room temp. That's not the problem.

    So assume that I'm using it wrong. But this is where it gets frustrating because I don't understand in what way. I get consistently good results using instant-read thermometers while the digital units with remote probe reads anything between 30 and 50 F higher on the same piece of meat.

    For example, yesterday I pan roasted a pork loin. The meat is about 16 inches long and 4 in diameter. I insert the probe length-wise down the meat so that the tip of the probe is in the center and most of the shaft of the probe is running centrally down the length of the muscle. After a suspiciously short time in the oven the thermometer reads 165 F. So I take the meat out and check. It is not cooked. It is soft, not firm, the instant read shows about 120 F and the juice from the instant read insertion is as you'd expect for undercooked pork loin. So I get rid of the digital thermometer probe and finish the job using my old technique.

    I've tried to use these thermometers with the same kind of pork loin 4 times since August always with the same result: the thermometer says it's done when it's not. I tried using it with a roast chicken once too and that was useless in exactly the same way.

    I've read a lot of web pages and forum posts on the subject of how to use these instruments and they seem consistent in describing technique. I did not read anything to suggest reading too high is typical. So this kind of device works for other people but not me. However, I can't figure out what I'm doing wrong. And I don’t believe my thermometers are malfunctioning.

    The only way I can understand it is that the thermometer is reading some temperature between the oven air temperature and that of the meat. Assuming the thermometer is of a type suitable for the task, the probe has to be inserted incorrectly. But I insert the probe according to conventional instructions and as I do an instant read (which have always worked for me).

    Any ideas or suggestions? Besides checking them out.

    TIA

    Frustrated in Boston
     
  2. mhpr262

    mhpr262

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    Have you contacted the manufacturers?
     
  3. kokopuffs

    kokopuffs

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    Is the probe placed next to the bone.  If so you'll get an unusually high reading, the bone heats faster than the meat.  Move the probe away from the bone.
     
  4. dreamshards8

    dreamshards8

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    Did you remove the meat from the oven and then temp it? Some instant read thermometers will definitely pick up heat around them and give you a high reading even if the meat is not cooked.
     
  5. dillbert

    dillbert Banned

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    >>If so you'll get an unusually high reading, the bone heats faster than the meat.

    not so sure this is accurate . . .
     
  6. kokopuffs

    kokopuffs

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    ...'been my sperience with boston butts when the probe was laid too close to the scapula, the seven bone.  The temps waivered widely.
     
    Last edited: Dec 25, 2013
  7. dillbert

    dillbert Banned

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    conventional wisdom has it that meat will be cooler closer to the bone.

    bones, being chock-a-block full of air cells, do not get hot faster than the meat - the air acts as insulation.

    I'm curious if anyone turns up some info on this.  I've often wondered if "oven heat" would be transmitted down the length of the probe and "fool" the tip.

    inserted - as described - lengthwise to the mid-point that would be roughly 8 inches of probe in the meat - seems unlikely much "false heat" is going to travel that far....
     
  8. flipflopgirl

    flipflopgirl

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    A short google session turns up many do not touch bone with probe warnings.
    Only one actually said why tho...
    Seems the bone will get hotter faster.
    Which is what I was told oh so many years ago (Dilbert you actually made me ? my Gma Van!)

    mimi
     
  9. dcarch

    dcarch

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    A quick experiment you can perform:

    With a rubber band and wrap a little paper towel around the metal shaft just before the measuring tip of your probe thermometer. 

    Pour boiling water over the paper towel. Making sure no hot water gets on the measuring tip.

    In a few seconds you will see the thermometer measures significant temperature rise.

    This experiment will show you how the metal conductivity can distort your measurements, especially if you leave the probe in the meat for a long time.

    dcarch
     
  10. dillbert

    dillbert Banned

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    that's the wonder of the internet.  check this:

    http://www.finecooking.com/item/30438/roasting-meat

    /quote

    Roasting meat on the bone also produces tender, rare meat near the bone (hence the phrase "tender at the bone"). That's because the honeycomb air pockets in bones make poor conductors of heat. Bones slow down the cooking, causing meat near the bone to roast at a slower rate and remain more rare.

    /unquote

    and here it says both:

    http://amazingribs.com/tips_and_technique/mythbusting_bone-in_meat_is_better.html

    section "Thermal Impact . . ."

    /quote

    Bones can have an impact on heat transmission. Some bones, particularly those that have a honeycomb like interior, are slow to heat up because they are a Styrofoam-like insulator filled with air pockets. Then when they get hot, they can retain heat longer than the meat..............So, depending on how long you cook, the meat closer to the bone can be slightly more or less cooked than the meat just half an inch away.

    /unquote

    basically, one can find any opinion needed.
     
  11. flipflopgirl

    flipflopgirl

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    You caught me, Dillbert!

    I googled and did a short search of all the sites on the first page, lol!

    So what am I missing here?

    I have been taught all my life to place the probe in the meatiest part of the protein and to avoid any/all bones.

    mimi

    *good thing I rarely use a thermometer!
     
    Last edited: Dec 26, 2013
  12. dcarch

    dcarch

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    "----That's because the honeycomb air pockets in bones make poor conductors of heat. --"

    I am not totally convinced. 

    The honeycomb structure seems to me are not empty air pockets. They are filled with blood, liquid or marrow.

    Perhaps the meat fibers are not the same when they are near the bone.

    Perhaps the bones are mostly on the bottom when you are roasting in the oven where it is colder in temperature.

    dcarch
     
  13. cheflayne

    cheflayne

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    The best digital insta-read thermometer that I used and come to trust over the years is...

     
  14. dillbert

    dillbert Banned

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    >>So what (are we) missing here?

    most likely a batch of specifics and details.

    a whole ham, with the bone buried in the middle

    vs

    a T-Bone steak - thinner / (more?) exposed bone

    vs

    standing rib roast, cut from bone then retied

    vs

    standing rib roast, not cut free from bone

    vs

    chicken! white meat dark meat meat meat . . . .

    and, as dcarch points out, bone is not bone . . . nor is bone "homogeneous"

    "the internet" says bone heats faster, it also says it's an insulator and heats slower - if this is true, the only explanation is:  "It's the bone!" - i.e. bones be different.

    in my old age I've collected enough experience to judge steaks/chops by feel - so I'm only temperaturing roasts.

    using an instant read, going slowly from outside to bone  has always been hotter to cooler - right down to bone contact.

    so why thefsb sees higher temps is a puzzle to me.
     
  15. dcarch

    dcarch

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    I have not check the facts. I think fat is less conductive than meat. The maximum temperature of meat is about 212 F, but fat can get much higher because of much higher boiling point (400 F?)

    If you withdraw your instant read probe out from the meat slowly and pass thru a fat cap, your reading can be much higher.

    dcarch
     
  16. dillbert

    dillbert Banned

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    the OP is using a stay-in-place probe - stuck about 8 inches into the roast - the probe is not moving around / through anything but is reading too high - and investigation and a separate thermometer indicates the meat is factually not 'done'

    the question is what is 'fooling' the probe thermometer.....