Sushi with ambition at B2 Bluefin in Bala Cynwyd

As I stepped into the midst of a boisterous happy hour in the corporate sleekness of B2 Bluefin in Bala Cynwyd, it occurred to me that sushi in America has undergone one of the most dramatic image makeovers of any food I've ever seen.

Two decades ago, it was largely considered the exotic and luxurious domain of adventure eaters. These days, sushi is so mainstream you can get your spicy tuna rolls in most any grocery store, hospital cafeteria, or suburban strip mall. It has also made the pizzalike leap beyond its international niche, oftentimes merging with crudo, ceviche, poke alongside other more familiar raw-bar offerings to become a modern staple in the New American menu lexicon.

But sushi's ubiquity has not always equated to rising standards. In fact, I'd argue the opposite. The proliferation of cheap sushi counters slinging generic tuna, salmon, and yellowtail beneath a colorful blitz of fish roe and spicy mayo has blinded the public's ability to discern among the good, the bad, and the great.

And great sushi, aside from being inevitably more pricey, is always about subtle nuances - the decisive knife craft of a skilled chef's slice (with implications for mouthfeel and flavor), the texture and seasoning of the rice (which can amplify the character of the fish), the carefully built architecture of a roll (so every element sings in harmony), and especially the quality of the fish, which, in its most elemental forms, as plain sashimi or nigiri-style over a ball of rice, says all.

And the toro taster at B2 speaks oceans about the capabilities of this five-month-old branch of East Norriton's Bluefin. It begins with a 500-pound Spanish beast, purchased whole for about $10,000 by owner and chef Yong Kim. Sliced into glistening strips on the plate, it's a rainbow of purples and pinks, each slice passing across my palate with a different balance and character of meatiness and fat. The more deeply colored akami (which means "red meat") tastes like some exotic fruit. The most marbled strips of alabaster o-toro from the belly melt like butter into an omega-3 buzz.

This is the kind of quality you'd expect at the best fish venues in Center City, which, aside from stalwarts Zama and Morimoto, has had a sudden bump in ambitious new sushi hubs, like Royal Izakaya and Double Knot. Kim's battalion of sushi chefs also benefits from regular arrivals of the "mystery box" containing smaller and less-common Japanese specimens (mejina rudder fish, inada baby yellowtail) that purveyor Samuels & Son delivers to its premium clients.

You will likely not mistake B2 as an overall experience, though, for one of those three-bell stars. The service has solid moments at the beginning, articulating well the many fish and surprisingly tasty Japanese-themed cocktails. But then they'll disappear when you need them most, or accidentally appear with the wrong plates (twice) meant for a neighboring table.

Kim spent a fortune to give the sun-filled 163-seat former steak house on the ground floor of this City Avenue corporate center a contemporary look. With white faux-leather furniture and mod chandeliers of dangling illuminated rings, it's certainly more swanky than Bluefin's home base, a 94-seat BYOB that's a staple in East Norriton. But I find the room a bit cold for nonbusiness dining, with no apparent soundproofing to dampen the piercing howls of happy-hour revelers in a bar whose multiple TVs flash intrusively from behind a transparent partition along the dining room.

And then there's the menu, which is as guilty as the next midrange sushi joint of the typical mix-and-match shell game, in which four or five basic fish are simply rearranged repeatedly into dozens of vaguely different combinations and pose beneath colorful blasts of roe and sauce. And even Yong will concede his menu is also full of legacy dishes that suddenly seem dated - the "sundaes" of tuna or fried rock shrimp piled into a parfait glass with cashews and spicy mayo, the sweetly broiled slice of miso-glazed Chilean sea bass, the "spinning shrimp" wrapped in (too much) crispy pastry, even the wasabi shumai I can't resist, though they're not homemade, because I prize their sinus-clearing rush.

Just because they're cliches doesn't mean they're not delicious. And yet . . . Bluefin is better than average, and has always distinguished itself from suburban sushiland's vast middle tier through its steady quest for better ingredients and an urge, when possible, to show finesse.

The usuzukuri is a prime example, in which gossamer ribbons of fluke (the thinner the better) come with a yuzu-tart ponzu. A special ramp roll shows a rare flash of seasonality, in which sautéed ramps bring their wild onion zing to the buttery mince of toro tuna belly. A tightly wrapped naruto roll uses shaved cucumber, instead of the usual seaweed and rice, to wrap a colorful mosaic of tuna and salmon with the contrasts and flavors of sweet-tart mango, creamy avocado, and the crimson pop of tobiko roe.

For the most part, the multitude of specialty rolls hovering reasonably around $16 are good but not exceptional, with a few totally blurring in my memory (Was it a Bentley? A Main Line? Or a Tornetta?). I do remember the Boathouse for a high note of sweet fish richness that reminded me how underrated good salmon can be, especially with the spark of spicy crunchy tuna at its maki core. I also admired the flavors of Yong's oyster mushroom roll, a clever vegetarian riff with crispy shreds of the mushroom in a truffled umami glaze, even if its presentation was unwieldy.

Considering a couple of the excellent hot appetizers, like the chef's special dumplings stuffed with garlicky beef and cabbage in a dashi broth, or the exceptionally meaty - but maybe too edgy for most Main Liners - broiled yellowtail collar, I wonder if B2 shouldn't attempt to add more cooked items for non-sushi eaters. Then again, after sawing through a filet that was cooked strangely with the meat's grain running sideways, this kitchen may not have the consistent hotside chops.

Striving for that next level of sushi ambition is clearly more within B2's reach. That was most obvious on the chef's choice platter of the omakase sashimi, which was even more generous portion-wise than I expected for $50. Many of them were delicious rarities from the evening's mystery box, and the caliber and complexity were undeniable, each plush pad of fish leaving a sensual stamp of its personality on my lips and teeth - the lean snap of kuro dai black bream and baby kurodai red snapper, the porcelain smooth sweetness of live scallop, a slice of hon-maguro cut from the bluefin's collar so shot though with speckled fat it simply dissolved like tuna lardo.

Of course, some sheets of fish were cut a shade too wide for easy one-bite eating. They actually looked sort of like bundled socks on the plate. But style points, consistency, and more refinement are the next step if B2 wants to make that next move. Sushi has come so far in the American mainstream landscape the Main Line deserves a destination with that kind of potential.

Next week, Craig LaBan reviews Rooster Soup Co. near Rittenhouse Square.

claban@phillynews.com

215-854-2682

@CraigLaBan

www.philly.com/craiglaban

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