The 2008 TIME 100

I know of no chef worth his salt who doesn't keep a copy of Harold McGee's masterwork, On Food and Cooking: The Science and Lore of the Kitchen, close at hand. Simply put, it is the Rosetta stone of the culinary world. Before it, cooking was governed by tradition, superstition and dogma. Armed with reason and natural curiosity, McGee flipped on the science switch, and suddenly there was light.

Whereas Julia Child taught "how," McGee explains "why." Now we know why eggs, meat, water, sugar and countless other ingredients do the things they do. We know what happens during the sauté and the roast. The agents of fermentation, of leavening, of caramelizing are no longer mysteries. McGee, 56, is so influential a figure not because he was the first to write about such things but because he was the first to approach them as a cook rather than as a lab technician. You don't need a chemistry degree to grasp what he's saying. McGee's work is readable, practical and as useful as duct tape. I feel certain that were it not for McGee, the course of my own life and career would be very different indeed.

Brown is host of Good Eats and Iron Chef America and a James Beard Award winner