The Food Lab: Better Home Cooking Through Science

this added energy goes to raising the temperature of the
steak, but much of it gets used for other reactions: it takes
energy to make moisture evaporate, the chemical reactions
that take place that cause browning require energy, and so
on.
Temperature is a system of measurement that allows us
to quantify how much energy is in a specific system. The
temperature of the system is dependent not only on the total
amount of energy in that body, but also on a couple of other
characteristics: density and specific heat capacity.
Density is a measure of how many molecules of stuff
there are in a given amount of space. The denser a medium,
the more energy it will contain at a given temperature. As a
rule, metals are denser than liquids,‡ which, in turn, are
denser than air. So metals at, say, 60°F will contain more
energy than liquids at 60°F, which will contain more energy
than air at 60°F.
Specific heat capacity is the amount of energy it takes to
raise a given amount of a material to a certain temperature.
For instance, it takes exactly one calorie of energy (yes,
calories are energy!) to raise one gram of water by one
degree Celsius. Because the specific heat capacity of water
is higher than that of say, iron, and lower than that of air, the
same amount of energy will raise the temperature of a gram
of iron by almost ten times as much and a gram of air by
only half as much. The higher the specific heat capacity of a
given material, the more energy it takes to raise the
temperature of that material by the same number of degrees.
Conversely, this means that given the same mass and
temperature, water will contain about 10 times as much