Page 114 - Turkey Book from Meathead

he USDA doesn't factor in carryover either.
Carryover is simple physics. Here’s how it works: In a 325°F oven, the surface of the meat will slowly warm. This warming is the process of exciting the molecules so they move faster. It takes time because the meat is a combination of water, fat, and protein, and they are good insulators.
As the surface warms it conducts its heat slowly inward to the cooler cells beneath, passing it along like a bucket brigade. Excited molecules get their neighbors excited by bouncing o them like billiard balls. Slowly the heat marches towards the center.
As the exterior passes the heat along, it loses heat, so the bucket brigade prevents the surface from zooming up to 325°F. Also, moisture on the surface evaporates, cooling the surface in the same way sweat cools you o on a hot day. Not to mention that, because meat is mostly water, it can’t get much above 212°F. If the meat is thin, the heat builds up rapidly. If it is thick, it takes much longer to get to the desired temp in the center. The trick is to get the center to
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