medium as water or oil, so air molecules collide with the food less often, and take longer to impart energy to it Second, a cool object in a hot oven develops a stagnant “boundary layer” of air molecules and water vapor that slows the collision rate even further (A convection fan speeds cooking by circulating the air more rapidly and disrupting the boundary layer.) Third, in a dry atmosphere the food’s moisture evaporates from the surface, and this evaporation absorbs most of the incoming energy, only a fraction of which gets to the center So baking is much less efficient than boiling or frying Of course, the oven’s thin medium is why the oven is a good means for drying foods, either partly — for example, to concentrate the flavor of watery tomatoes — or almost fully, to preserve and create a chewy or crisp texture And once the surface has dried and its temperature rises close to the oven’s, then carbohydrates and proteins can undergo the browning reactions, which generate hundreds of new taste and aroma molecules and so a greater depth of flavor Often vegetables are coated with oil before baking, and this simple pretreatment has two important consequences The thin surface layer of oil doesn’t evaporate the way the food moisture does, so all the heat the oil absorbs from the oven air goes to raising its and the food’s temperature The surface therefore gets hotter than it would without the oil, and the food is significantly quicker both to brown and to cook through Second, some of the oil molecules participate in the surface browning reactions and change the balance of reaction products that are formed; they create a distinctly richer flavor Frying and Sautéing Baking oiled vegetables is sometimes called “oven frying,” and indeed true frying in oil also desiccates the food surface, browns it, and enriches the flavor ... important consequences The thin surface layer of oil doesn’t evaporate the way the food moisture does, so all the heat the oil absorbs from the oven air goes to raising its and the food? ??s temperature The surface therefore gets... The surface therefore gets hotter than it would without the oil, and the food is significantly quicker both to brown and to cook through Second, some of the oil molecules participate in the surface browning... reactions and change the balance of reaction products that are formed; they create a distinctly richer flavor Frying and Sautéing Baking oiled vegetables is sometimes called “oven frying,” and indeed