There's nothing that quite compares to the flavor grilling brings out in vegetables. It's a simple enough cooking method, but why does it produce such a delicious result? It's all about chemistry.

The intense heat of a gas or charcoal grill first dehydrates vegetables, and then sparks a reaction between sugar and protein molecules. Called the Maillard reaction, it produces an array of aromatic and flavorful compounds, says Robert Wolke, author of What Einstein Told His Cook 2 (W.W. Norton). The same reaction happens when you roast vegetables or meat in the oven, although they don't have the added smoky flavors the grill imparts.

This reaction is different from caramelization, which requires only sugar. And it can't happen when using moist heat methods, such as steaming. Only food that contains both sugar and protein and is cooked with dry, high heat can create what Wolke calls "delicious browning."

"People have been cooking food over a fire since caveman days," says Wolke, who favors corn grilled in its husk. "Because of the high temperatures, it does give food unique flavors that you can't get as easily in the modern kitchen."