Drive southeast from Dijon in France, across the broad plain of the Saône River, until the land starts to roll and the Jura Massif looms gray on the horizon, and you're in the Franche-Comté--Pasteur country. The great Louis was raised in Arbois, a small town nestled at the base of the Jura cliffs. You can still visit his ivy-covered childhood home, where his father tanned hides and where in later life Louis installed a bathtub (one of the first in town) as well as a laboratory in which to pass his summer holidays. On shelves in the lab stand the flasks of chicken broth--made in 1883 and untouched since--with which Pasteur disproved the theory of spontaneous generation. In the opposite corner is the saunalike room where he tested the effects of heat on microbes. It was Pasteur, of course, who discovered that you could kill microbes by heating them--or "pasteurizing" them, as people would later call it.
To make a Swiss cheese, an American cheese maker begins with raw milk and adds rennet.
