Prism Brewing's Tap Room operates in a North Wales industrial park

IT'S A MOONLESS Thursday night in North Wales, Montgomery County. Down a dead-end street just past the giant Merck & Co. pharmaceutical plant, tucked along the SEPTA R5 railroad tracks, a darkened industrial building attracts a young crowd. The unpaved parking lot is full, light sounds of live jazz seep from the rear door, and the air carries the familiar aroma of malt.

Welcome to Prism Brewing's Tap Room, one of the region's best-kept beer-drinking secrets and, it turns out, a harbinger of a remarkable surge of suburban breweries.

Prism opened the place last July, after months of making beer at the now-defunct General Lafayette Inn in Lafayette Hill. Its small, unadorned bar seems almost an afterthought, its main feature a large showroom window offering a view into the brew-house where sweaty guys haul hoses and kegs. A dozen or so tables are scattered through the tiny room. There's a jukebox, a couple of TVs, some arcade games (Golden Tee!). There's no kitchen, but you can order from the "gourmet hot dog menu."

It reminds me of Northern Liberties circa 1988, before everyone discovered the neighborhood.

Yet without a word of advertising, the Prism Tap Room has begun attracting strong crowds on most evenings — a mixed audience drawn by the brewery's unusually flavored ales and its underground atmosphere.

"When it comes to real estate, everyone says 'location, location, location,' " said owner, head brewer and, according to his business card, "Mad Scientist" Rob DeMaria. "But we have the world's worst location, and it turns out it's one of our biggest assets."

Well, that and the beer.

Prism has a rep for unusually flavored beer. DeMaria, a former Merck employee, has his roots in homebrewing and, like many do-it-yourselfers, he's accustomed to flavoring ales with offbeat ingredients.

Bitto Honey, Prism's flagship India pale ale, is sweetened with honey. ParTea Pale Ale, spiced with tea leaves, is herbal. Red Zone gets a zing from ginger, nutmeg, allspice and maple syrup. Shady Blond is made with blood oranges.

The brewery has begun bottling and its beers are increasingly available on local taps, including one at Citizens Bank Park. But make the trip out Sumneytown Pike to the brewery for a fresh taste in its funky Tap Room, at 810 Dickerson Road, North Wales.

Bring a thirst. And your GPS.

Hops in the 'burbs

The northwestern suburbs are suddenly hopping with new breweries. Since Prism's opening, four others have fired up their kettles in a 20-mile radius in the quadrant north of the Pennsylvania Turnpike and east of the Northeast Extension.

Round Guys, 324 W. Main St., Lansdale. Rich DiLiberto (another former Merck employee) teamed with longtime homebrewing pal Scott Rudich to open a small brewery focusing on "well-rounded" beers. "Rich is into malt and I'm a hop head," Rudich said, "So we had to make a beer that satisfied us both."

Their first three styles are a Belgian-style tripel, a black IPA and a Berliner weisse.

The beer is available only at a handful of bars, including the Blue Dog Pub in Lansdale and the Sidebar in West Chester. A brewhouse pub is in the works, but for now you can pick up growlers to go at the brewery on weekends between noon and 4 p.m.

Free Will, Perkasie. Both John Stemler and partner Dominic Capece got their start as homebrewers, eventually morphing their hobbyist equipment into a full-scale, 7.5-barrel professional system.

They don't run a tasting room, but that's OK because Free Will is already available in about 40 area bars. Citra Pale Ale, a refresher made with distinctive, lemon-like hops, is its flagship. The one that gets you scratching your head is Pale Stout, a malty ale that tastes like Guinness and looks like Bass.

Forest & Main, 61 N. Main St., Ambler. The loooong-awaited brewpub from brewers Gerard Olson and Daniel Endicott finally opened last weekend, and the locals are already embracing the place. Operating out of a converted 19th-century house in the lively borough's growing restaurant district, the pub is a series of small, quaint rooms whose design and renovation was completed almost entirely by the two partners themselves.

Their beers — an unusual pairing of British and Belgian styles — show the same careful craftmanship. Tiny Tim is a full-bodied English bitter that, with just 3.5 percent alcohol by volume, may be the very definition of a session beer. Lunaire is a superb Belgian-style saison whose complex, lightly sour flavor is the product of two months in a wine barrel. Don't look for wings or nachos on the menu; entrees are fresh and include a $15 burger, lamb pie and roasted chicken. Order a $6.50 flight of four beer samples to pair with the bacon popcorn.

Doylestown Brewing, Doylestown. The newest guy on the block is Joe Modestine, whose family has been around for years, operating several restaurants in Montgomery County. This is his first brewery experience, and he readily acknowledges he's not a craft beer expert. "I'm aiming for introductory beers for people who are more mainstream beer drinkers," he said.

His brands will be contract-brewed by consultant Bob Klinetob at City Brewing, the former Rolling Rock plant in Latrobe, Pa. Modestine said he's hoping to open his own production facility in downtown Doylestown this summer.

Look for Union Street IPA, 90-calorie Fountain House Light and R5 Lager on draft, with bottles and cans available in June.

"Joe Sixpack" is by Don Russell, director of Philly Beer Week. For more on the beer scene, sign up for his weekly email update at www.joesixpack.net. Email: joesixpack@phillynews.com.