Rent-a-cops hunched in the rain outside, directing traffic with light wands. And by the door, Mayor Nutter's security detail was tracking his painfully incremental advance.

It was the opening night of Philly Beer Week, at last count an astonishing sprawl of 200 (mostly sold-out) events - South Philly pub crawls, local brewer talks, and at one venue, a "gourmet meatball slider tasting."

The mayor, of course, was late. The amiable crowd was reduced to dulling the pain with samples of Dogfish Head's malty Raison D'Etre, and a ruby farmhouse ale from Philadelphia Brewing called - in one of the more inspired name choices of late - Rowhouse Red.

But Nutter did get there in time to tap an inaugural keg of Yards' Extra Special Ale, and to note in an official proclamation that while Philadelphia had previously staked a firm claim in matters of history and, last week in particular, horticulture (i.e., the Flower Show), it was about to annex new territory - as America's best place to quaff exceptional craft beer.

To seal the deal, he tipped a pint - with the TV cameras rolling - and took a dainty sip. A cry went up: "Chug chug, chug!", though there was a self-conscious daintiness in that, as well: This wasn't your father's frat house.

Indeed, if there was anything revelatory about Beer Week, it has been its counterintuitive, almost-nerdish seriousness. (What's "craft beer"? It's made exclusively from flavorful barley, undiluted by the cheaper rice and corn extenders used by the big guys.)

On Saturday, at the German Society's big, old hall on Spring Garden Street, wine-and-beer maven Marnie Old delivered a lively, but studiously academic lecture on the city's German beer heritage. The house was packed. (Hefe means yeast; weisse means wheat. Thus, yeasty German hefeweizens sometimes smell like baked goods; banana bread, even.)

Tonight, for another example, Johnny Brenda's, the update of a Fishtown blue-collar bar, is hosting the city's First Annual Philly Beer Geek Finals, testing levels of brew trivia.

In fact, a California couple who blog about beer travel at thebeergeek.com were among 10 "beer press" (from Sacramento to Toronto) flown in for an expenses-paid taste by the Greater Philadelphia Tourism Marketing team, one of the sponsors.

They sipped George Washington's favorite porter at City Tavern. Visited Sly Fox's brewpub in Royersford. Ogled the hundreds of bottles of exotic beer on the wall at the Foodery in Northern Liberties. Ate cherry-sauced smoked duck at Monk's, the Belgian beer bar.

Not every quarter has reported in yet. But thebeergeek.com was quick to deliver its online verdict: Philadelphia's beer culture, it blogged, "is worthy of your beer travel dollar."

Even, it would appear, if you're paying your own way.

Contact columnist Rick Nichols at 215-854-2715 or rnichols@phillynews.com. Read his recent work at http://go.philly.com/ricknichols.