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Cooking a Turkey:
A Public Radio Commentary
by Bill Hammack
Listen using RealAudio
In engineering parlance we are faced this Thursday with a very
tricky heterogeneous, heat transfer problem. That's a complicated
way to say that cooking a turkey well is tricky.
Heat transfer is an essential part of an engineer's work. You can
see the results all around you: Open you car's hood and you'll
see a radiator. Or, listen to your computer. The optimal position
of its cooling fan is found by a heat transfer calculation. The
same techniques can be applied to figure out exactly how to cook
a turkey.
The problem is this: The breast and the legs cook at different
rates. The breast is composed of white meat, and the legs contain
dark meat, which has more muscle and connective tissue than the
white meat. The goal is to cook the turkey just long enough to
break apart this tissue, so that the turkey becomes succulent.
That is, the tissue turns to gelatin, which gives a velvety
feeling in the mouth.
To achieve this you want the breast to be cooked to 155 degrees
Fahrenheit, no more than 160 or it will be too dry. Yet, you want
the dark meat to be 180 degrees and above. Under 180 it's
unpleasantly chewy and even has a metallic taste. There's the
problem: The white breast meat cooks faster than the leg meat,
which means it's done well before the dark meat ever reaches the
right temperature.
So, how can you avoid, this year, having to pour gravy all over
your turkey to disguise its dryness? Here are some engineering,
heat transfer cooking tips. First, make sure the turkey is fully
thawed. Usually its best to do this in the refrigerator,
otherwise the turkey could spoil. The second tip is very
controversial: Don't stuff the turkey. It just messes up the heat
transfer. By the time the stuffing is fully cooked, the turkey is
overcooked by 60 degrees or so.
Third, before cooking cover the breast with an ice pack. As the
rest of the turkey comes up to room temperature, the breast will
be about twenty degrees cooler. This will solve our holiday heat
transfer problem: it'll slow down the cooking rate of the white
meat of the breast, making it cook about as fast as the dark meat
in the legs.
The last suggestion is obvious, but not always followed: use a
thermometer, two if possible. Pull out the turkey when the breast
reaches 155 to 160 degrees, and check that at the same time the
dark meat is 180 degrees.
Then stop thinking about heat transfer and enjoy your
Thanksgiving meal.
{These cooking tips come from Food Scientist Harold McGee. You
might check out his book On Food and Cooking for more details.}
Copyright 2004 William S. Hammack Enterprises
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