It may be hard to imagine now, but American ale-drinkers previously had few alternatives to the mass-produced beers that The Economist once (not incorrectly) deemed "fizzy dishwater." In fact, there were only two craft breweries in America in 1977. By 2012, that number had risen to 2,751, and while macrobreweries such as Anheuser-Busch and MillerCoors still dominate America's beer market, craft breweries are estimated to account for about a tenth of the industry's revenues.

While observations abound about "the rise of America's craft breweries," the story has been very different on the state level. Vermont, for example, had one brewery for every 25,000 residents in 2012. Mississippi, meanwhile, had one for every 994,500. These aren't anomalous islands of booziness and temperance—they're exemplars of their regions. The nine states with the fewest breweries are all in the South. What is it about the region that might make this true?

In short, it's because of the Baptists. Steve Gohmann, a professor of economics at the University of Louisville, recently published a paper in Entrepreneurship Theory and Practice cataloguing the potent blend of regulation, religion, and corporate interest that makes the South less hospitable to small breweries.

The Number of Baptists (in Red) and the Number of Breweries (in Blue) per State

Steve Gohmann

Around the nation, big beer producers contribute to the campaigns of politicians who will support policies that discourage competition from local upstarts—for example, taxes on breweries and laws that prevent breweries from selling their kegs directly to consumers (instead of through a distributor). But what's unique about the South is that there's a voting bloc—the Baptists—whose moral stance against alcohol happens to align with large producers' desires to keep new competitors from getting started in the business. The support of Baptists provides Southern politicians with a reason to hinder brewers that politicians in other regions don't have. As a result, the states with the most Baptists tend to have the fewest breweries.

What Gohmann found is a correlation, of course, but it's a convincing one. There's no counter-argument that Southerners simply don't like beer: Louisiana happens to be the state with the 10th-highest beer consumption per capita, and South Carolina isn't far behind. And while there are other religious groups—Mormons and Muslims, to name two—that abstain from alcohol and live in high concentrations in areas with lots of breweries, those groups, unlike Baptists, take firmer stances on what they themselves can drink than on what others are allowed to.

In fact, there's even more of a religious pressure for temperance in the South than Gohmann has it. While Baptists take the strongest position against alcohol, Methodists have also publicly advocated for temperance. "Between the two of them, they account for a very large proportion of the population in the South," says Nancy Ammerman, a professor of sociology at Boston University.

(Ammerman notes that these stances are "ironic, since in the really long history of the region, both Baptist and Methodist preachers were often paid in whiskey." And in practice, plenty of modern-day Baptists and Methodists no longer hide their consumption of alcohol. "The old joke was that no two Baptists ever said hello to each other in the liquor store," she says.)

Even though the South doesn't have many breweries, it does have plenty of whiskey distilleries—Kentucky, Gohmann said, is the American capital of whiskey. What do Baptists, Methodists, and their votes have to say about that? "My results are less likely to apply right now because microdistilleries are not capturing that much of the market from the large producers," he says. Without bigger-scale whiskey makers pushing in the same direction, Baptists don't have as much sway over politicians.

Policies like tax exemptions and the absence of distribution restrictions may be dry explanations for the flourishing of American craft beer, but the history of American breweries in the past 100 years has been shaped more than anything else by regulation. The ultimate regulation, of course, was Prohibition, which kicked in in 1920 and put 1,568 breweries out of business. Most of the roughly 700 that survived were squashed by a few large-scale brewers, who favored policies that demolished competition. (In 1923, the president of Anheuser-Busch wrote an urgent letter to President Calvin Coolidge, calling saloons that sold their own beer without a distributor "objectionable.")

The Number of Active Breweries in the U.S., by Year

Beer Institute

By 1983, only 49 breweries existed, and America's DIY beer culture was nonexistent. But after a longstanding ban on homebrewing was repealed in 1978 and states started legalizing brewpubs (breweries that sell 25 percent of more of their beer on premises) that same year, an opportunity had opened up. And in 1991, the federal government kept in place a tax break for small brewers, further opening the doors for homebrewers to start playing around in their basements, hitting upon new recipes, and deciding to open up pubs of their own.

And that's why many Americans are no longer stuck with fizzy dishwater—unless, of course, they live in the South.