Salt closed in less than two years. And yet, as I tucked into some mind-teasing nibbles recently at Snackbar, a successor in both location and culinary spirit, it struck me that very few places in the last decade have been as influential as Salt. Not because we pine for lemony duck tongues, but because of the inspired young talents that emerged from its tiny, subterranean kitchen at 20th and Rittenhouse. Steven Cook, the owner and opening chef at Marigold Kitchen, was among the first (along with pastry chef Julia Kovacs). David Katz, now creating superbly clean contemporary fare at Restaurant M, is another.

Jonathan McDonald, 28, is the latest Salt pot-shaker to emerge on the local scene, and though he's traveled considerably in the meantime - to Marigold, Mugaritz in San Sebastian, Spain, and Gilt in Manhattan - he hasn't landed far away. No wonder Snackbar, its glassy corner room warmed by the now-vintage steel fireplace, feels vaguely like a Salt reunion.

The location is a bit of a coincidence, according to 26-year-old owner Jonathan Makar, Marigold's former manager. And to be clear, Snackbar's format is different, tuned to the small-plate grazing ethos of the day and inspired by a hotel lobby more than a sit-down restaurant, which explains the armchairs that are way too big for the little space (not to mention the annoyingly low, knee-knocking tables).

Snackbar is more of a casual all-day hangout with cutting-edge munchies and no reservations than a precious dinner-only destination. You'll need three to four of those little plates to make a meal (which can add up). But it obviously appeals to many - like the Penn lit professor who recently occupied a table for a record 11 hours straight ("lots of tea," said Makar), the La Colombe regulars who decamp to the bar when their cafe closes, and the labor lawyer who regularly feasts on brussels sprouts at the bar.

Those sprouts, tossed with shaved black truffles and toasted marcona almonds, are one of Snackbar's most seriously addictive whimsies, though I could do without the pouf of almond milk foam. It may be just the right soupçon of ethereal texture and fleeting emotion - but foam is such an overdone cliche. And while McDonald is bursting with a young chef's zeal for experimental mediums, it's his knack for stunning combinations and sharp execution that makes his best dishes sing, more than the powdered schmaltz or hot saffron gel (which reminds me, creepily, of an expensive hair-care product).

Among the hits are his twist on smoked fish and eggs, which presents seared fresh trout beneath soft-scrambled eggs enriched with hickory-smoked cream. Pork tenderloin brined for a day in white beer is an amazingly tender fulcrum for two extremes - an earthy spoonful of amaranth-grain porridge on one side, a richly dark pork jus lightened with cranberries and hibiscus tea on the other. His boneless chicken wings, slow-cooked for five hours in garlicky olive oil, then slicked with an Asian black bean barbecue sauce, are one of the catchiest haute-bar foods around.

McDonald still lets a few wild pitches fly. At one meal, the complimentary popcorn was dusted in a tongue-twisting clash of salty Old Bay and sugar. The miso-caramel-glazed apple wedges crusted in crushed wasabi peas tasted like a sake-bar snack fantasy gone awry. Simple cooking gaffes held back some otherwise clever ideas. The root-beer-braised brisket on a soda biscuit could have been more tender. The smoked paprika-dusted octopus over lemon-apple puree was rubbery. The Taleggio polenta was all cheesy ooze, with too little evidence of corn.

Perhaps it was just an off night, because on my next visit, it was as if the kitchen couldn't miss. Pan-roasted cauliflower basked in Madras curry and brown butter spritzed with lime. Gruyere "broth" was poured tableside around a stack of crisp fingerling potatoes. But the surprisingly thin liquid, steeped from the curds like tea, managed to convey the cheese's full richness.

A warm saute of gorgeous wild mushrooms gets a quick-pickling splash of vinegary verjus - whose exotic, clovey spice was a perfect match for a snifter of Canadian apple beer, Ephemere. It was one of the highlights of Snackbar's tiny drinks list, which offers, as well as other good Unibroue and Hitichino beers, about a dozen wines, though most of them, oddly, are variations on syrah.

The after-dinner sherries and ports, though, were a particularly apt treat - especially given McDonald's unique talent for presenting cheese in compositions. Like the Blackstick blue wrapped in a tube of apple-mustard paper beside the hollowed-out crust of a croissant. Or the Spanish goat cheese called Nevat, which came over sweet grape-must syrup with a slice of candied pumpkin and a savory candy bar of hazelnut truffle crunch.

Snackbar's actual desserts, though, are also worth notice, especially the warm curried banana that came rolled in cilantro bread crumbs with salted caramel and vanilla rum powder. It was like some futuristic Bombay Bananas Foster fantasy - intriguingly spicy, fruitily sweet, and yes, of course, a little salty, too.

Contact restaurant critic Craig LaBan at 215-854-2682 or claban@phillynews.com. Read his recent work at http://go.philly.com/craiglaban.