The relatively mild flavor of most vegetables and fruits is intensified by cooking. Heating makes taste molecules—sweet sugars, sour acids—more prominent by breaking down cell walls and making it easier for the cell contents to escape and reach our taste buds. Carrots, for example, taste far sweeter when cooked. Heat also makes the food’s aromatic molecules more volatile and so more noticeable, and it creates new molecules by causing increased enzyme activity, mixing of cell contents, and general chemical reactivity. The more prolonged or intense the heating, the more the food’s original aroma molecules are modified and supplemented, and so the more complex and “cooked” the flavor. If the cooking temperature exceeds the boiling point—in frying and baking, for example—then these carbohydrate-rich materials will begin to undergo browning reactions, which produce characteristic roasted and caramelized flavors. Cooks can create several layers of flavor in a dish by combining well-cooked, lightly cooked, and even raw batches of the same vegetables or herbs.