that is only because the edges shrink, giving the
illusion of a wider center. In fact, the exact opposite
is the case. Since the center of a medium-rare steak
is coming up to 125°F, it too is shrinking—and
forcing liquid out. Where does all that liquid go? The
only place it can: out of the ends of the straws, or the
surface of the steak. That sizzling noise you hear as
a steak cooks? That’s the sound of moisture escaping
and evaporating.
Give That Theory a RestSo why does an unrested steak expel more juices
than a rested one? Turns out that it all has to do
with temperature.
We already know that the width of the muscle
fibers is directly related to the temperature to which
the meat is cooked, and to a degree, this change in
shape is irreversible. A piece of meat that is cooked
to 180°F will never be able to hold on to as much
liquid as it could in its raw state. But once the meat
has cooled slightly, its structure relaxes—the muscle
fibers widen up slightly again, allowing them to once
again hold on to more liquid. At the same time, as
the juices inside the steak cool, proteins and other
dissolved solids cause them to thicken up a bit. Have
you ever noticed that if you leave pan drippings
from a roast to sit overnight, they are almost jelly-
like? This thickening helps prevent those juices from
flowing out of the steak too rapidly when you slice it.
I cooked a half dozen steaks all to an internal