... contemporary attitudes toward inebriation mean that "it's hard for people to take the study of alcohol consumption seriously," says Richard W. Unger, a professor of history at the University of British Columbia and the author of Beer in the Middle Ages and the Renaissance (University of Pennsylvania Press).

Mr. Unger says such attitudes stem from a failure to realize that brewed beverages were a necessity before the advent of dependable, clean water supplies or soft drinks.

In early modern Europe, "beer was a normal part of daily life," says Mr. Unger. With food often scarce, it was a nutritional godsend. It was also an all-purpose social lubricant, regarded with "neither suspicion nor awe," he says. Consumption per person far exceeded today's levels. For children as young as 4 years old, too, beer was a staple. Presumably they were fed weak brews, says Mr. Unger, but not too weak: "If the alcohol levels are low, the nutrition level is low, too."

So was medieval life like living in a college fraternity today? Perhaps so, for beer was brewed in one in 10 houses, all by trial and error, as modern methods of chemistry had not yet been developed.

"You couldn't walk down the street without smelling beer," says Mr. Unger.

The historical sources on beer are vast, Mr. Unger says, because "governments have regulated the production of alcohol since at least 3500 BC, and governments keep records."...