Some cooking methods move heat into the food faster than others.
The heat transfer coefficient is a measure of the speed of heat flow
from the cooking medium to the surface of the food.
Heating method: Heat transfer coefficient
natural convection from air: 20
water bath: 100-200
condensing steam:200-20,000
deep-frying: 300-600
Circulating hot oil transfers heat extremely
rapidly, so deep-frying is one of the fastest ways to
cook the surface of food. Beneath the surface,
however, heat propagates in frying food in the
same way it does in any other cooking technique:
slowly, through conduction. The mismatch between a fast-cooking surface and a slow-cooking
interior means that food needs to be sized just
right for deep-frying.
