If there is a downside to being one of the region's most respected brewmasters, it's that you are defined — and sometimes constrained — by your old hit beers. And for Brian O'Reilly, who was the kettle master at Sly Fox Brewery for 18 years before leaving recently to cofound Mainstay Independent Brewing Co., many of his successful early creations are now considered local classics: Pikeland Pils, Royal Weiss, Grisette, Saison Vos, and, of course, the O'Reilly's Stout that is such a great local alternative to Guinness.

But what if you want to change or tweak a recipe as time goes by? Not so fast.

Brian O’Reilly toasts with a Compound Kolsch from his new Mainstay Independent Brewery.
TOM GRALISH / Staff Photographer
Brian O’Reilly toasts with a Compound Kolsch from his new Mainstay Independent Brewery.

"Well, the customers already love it, and the salespeople freak out when you change a recipe," O'Reilly says. "I still like these beers, but maybe now I'd like to do them a little differently."

O'Reilly has that opportunity now to rethink his portfolio with his first ownership stake in a brewery at Mainstay, which opened at the beginning of November in the former Yards Brewing Co. site in Northern Liberties at 901 N. Delaware Ave. It's the first piece of Avram Hornik's new Craft Hall project, which by early next year will include food from a new location for the recently moved Lost Bread Co. and City Creek BBQ. (Yards moved to a larger facility at Fifth and Spring Garden this year.)

O'Reilly is considered one of the area's most technically sound brewers, so it's no surprise that the early round of Mainstay offerings I tasted — also brewed by Andrew Foss, a multiple Brewvitational award winner from St. Benjamin's — were clean and flawless.

Growlers of fresh beers from the new Mainstay Independent Brewery featured some strong takes on classic German styles.
TOM GRALISH / Staff Photographer
Growlers of fresh beers from the new Mainstay Independent Brewery featured some strong takes on classic German styles.

The classic German styles were the standouts. The cloudy amber King Laird Weisse (named in honor of Roslton Laird, who farmed wheat on Petty Island in the late 1800s) was vivid with yeasty banana-clove aromas without overdoing it. The refreshingly crisp Compound Kolsch, the lightest, driest of the bunch, sparkled with the white pepper notes of Tettnang hops. Glow Spice is a fall-spiced beer without the usual pumpkin, and though it's not a style I love, the use of fresh spices (rather than the usual extract) made it far less cloying. Harness Bend is a fascinating two-in-one beer experiment made from the wort of of King Laird Weisse that's transformed into an IPA with a blend of American hops that frame the biscuity wheat base with bright citrus. Poplar Pils is O'Reilly's fresh take on pilsner, with more German noble hops than Pikeland Pils that give this golden brew a brassy resonance that hangs in balance on the palate.

Is O'Reilly reinventing our concept of beer at Mainstay Independent? No, not yet with these well-crafted takes on familiar styles. But as O'Reilly takes hold of this prime opportunity to reinvent his brewing identity, his next chapter at the brew kettle at Mainstay Independent should hold some pleasant surprises.

— Craig LaBan

Mainstay Independent Brewing Co., 901 N. Delaware Ave., 215-422-3561; mainstaybrewing.com