The Food Lab: Better Home Cooking Through Science

rightfully say to yourself, “Ah, I wish I had battered that
first.”
Batters are made by combining some sort of flour—
usually wheat flour, though cornstarch and rice flour are not
uncommon—with a liquid and optional leavening or
binding ingredients like eggs and baking powder. They coat
foods in a thick, goopy layer. Breadings consist of multiple
layers. Generally a single layer of flour is applied directly to
the food to ensure that its surface is dry and rough so that
the second layer—the liquid binder—will adhere properly.
That layer generally consists of beaten eggs or a dairy
product of some kind. The last layer gives the food texture.
It can consist of a plain ground grain (like the flour or
cornmeal in a traditional fried chicken breading), ground
nuts, or any number of dry ground bread or bread-like
products such as bread crumbs, crackers, or breakfast
cereals.
No matter how your breading or batter is constructed, it
serves the same function: adding a layer of “stuff” around
the item being fried means the oil has a tough time coming
in direct contact with it, and thus has a hard time transferring
energy to it. All the energy being transferred to the food has
to go through the medium of a thick air-pocket-filled
coating. Just as the air-filled insulation in your house helps
mitigate the effects of harsh external conditions on the air
temperature inside, so do batters and breadings help the
food underneath cook more gently and evenly, rather than
burning or becoming desiccated by the fiercely energetic
oil.
Of course, while the food inside is gently cooking, the