Yes, even after turning off the heat source, the heat from the exterior of the food can continue to warm up the interior for a short period. This phenomenon is known as carryover cooking or residual heat cooking.
Carryover cooking occurs because food is not a uniform mass; it has varying densities and thermal conductivity. When you apply heat during cooking, the exterior of the food gets heated more quickly than the interior. Once you turn off the heat source, the heat from the outer layers of the food will slowly transfer towards the colder center.
The amount of carryover cooking depends on several factors, including the size and thickness of the food, the cooking temperature, and the specific heat capacity of the food itself. Larger and thicker cuts of meat, for example, tend to experience more carryover cooking than smaller, thinner pieces.
It's essential to consider carryover cooking when cooking certain foods, especially those that continue to cook even after they're removed from the heat source. To prevent overcooking, you can take the food off the heat slightly earlier than the desired doneness, knowing that it will continue to cook as it rests.
Resting the food, covered or loosely wrapped in foil, allows the heat to distribute more evenly throughout the entire dish. This resting period also gives the juices inside the food a chance to redistribute, resulting in juicier and more evenly cooked meals. For example, when cooking a large piece of meat like a roast or steak, letting it rest for a few minutes before slicing will result in a more tender and flavorful outcome.