But for an ashtray screwed to the top of a forbidding stairwell behind Sheffield’s town hall, you would never know that, below, lies OFM’s Best Place to Drink. Music drifts up from an entrance marked Public, but without any explanation of what is going on down there.

Other “hidden” bars would revel in that mystery. But not Public. Not in Sheffield.

“That word ‘speakeasy’ was nowhere near our press release,” says co-owner James O’Hara. “You go into so many bars now and they’re pretending to be some moody gangster’s cigar den – the bartenders look like they’re in Peaky Blinders, and they’re serving stirred-down brown drinks no one likes apart from other bartenders – and you just think, why?”

Public is discreet because it occupies a former gents’ toilet below the council’s Grade I-listed Victorian HQ. You cannot put signage up. It is literally underground. But it has a website. It is hiding in plain sight.

In this famously hype-resistant city, Public has found an audience, not by cultivating an air of exclusivity but by distilling contemporary cocktail culture into a package that, original and irreverent, serious and self-deprecating, is very Sheffield. Typically, the Public menu is being reprinted to celebrate this OFM award, but it will open with the bar’s first ever online review: “Worst pub I’ve ever been in, John, Facebook.”

Opened last November, Public’s design rejects glitzy cocktail bar cliche. It is glamorous, but in the knowing, 1970s-influenced way of Pulp album covers. Onyx-black tables edged with kitsch gold trim are surrounded by dark turquoise-green banquettes. Its Georgian wire-glass and retro wood panelling evoke lounge bars, but the lounge bars of northern working men’s clubs. Exposed ducting is painted a soft pink.

Head barman Jack Wakelin’s handsome drinks (no dry ice, no wacky garnishes; beautiful glassware, clever flavours, mainly priced £6 to £9), focus on locality and sustainability. He forages berries and douglas fir in the Peak District. His Public Awareness menu utilises what he describes with a grin as “tasty garbage”. Syrups are created from “flat pop”, Pedro Ximénez is infused with spent grounds from Steam Yard coffee, cordials are flavoured with waste citrus peels. This, the menu explains, is, “a vain attempt to alleviate our crushing guilt”.

“The waste in bars is disgusting,” says O’Hara.

In seven years, O’Hara and his business partner James Hill, AKA the Rockingham Group, have opened three venues in Sheffield including the much-loved Picture House Social, a bar, music venue, ping-pong hall and Neapolitan pizza place in the basement of Abbeydale Road’s historic cinema. Now both 36, their tastes have matured, but their approach is unchanged. They identify something Sheffield lacks. “When people say, ‘Oh, I don’t think that’ll work in Sheffield’, it pisses me off,” says O’Hara. They often work with like-minded locals such as designers Totally Okay, artist-potters Grey Suit Clay, vinyl store Bear Street Records. All of whom, as O’Hara puts it, “want Sheffield to progress”.

A co-founder of the Tramlines music festival, O’Hara is on the board of ReNew Sheffield, a project to utilise vacant properties in the city. That is how he found the toilet that became Public. Council officers were initially bemused by the idea, but in a city overlooked by hip national brands O’Hara hopes its success has proven a point. That, in order for food and drink to thrive in the city, as the arts and music already do, the council needs to empower Sheffield’s independents.

“Everything we do is through a prism of ‘we’re from Sheffield’,” says O’Hara. “You get fierce scrutiny when you do something new here, but if it’s good, Sheffield will get behind you. I think the council now understands that if you use the creatives who have stayed here, then the city will improve. Don’t get some London conglomerate in and give ’em a space in a city they don’t have a clue about.”

Raising Wakelin’s Queen of Jalisco (lovage-infused tequila, chicory-root tincture, hazelnut syrup, bitters), OFM will drink to that. Surrey Street, Sheffield, S1 2LG