When Joe Brennan was a boy growing up in Belfast, his grandfather took over a confectionery store in the Lower Falls area, and installed an illegal drinking club in it. Things that happened in the so-called 'Sweety Bottle', and the characters who drank there, swiftly became the stuff of family legend, and were much debated and discussed over the Brennan family dinner table. Forty years later, in collaboration with his son Gerard, Joe has woven a selection of Sweety Bottle stories together in a two-act play, revisiting a place now gone (levelled in the interests of urban redevelopment), but certainly not forgotten in the memories of those who grew up in the West Belfast area.

Good as the stories are (the audience is in a virtually constant state of hilarity), the danger is that The Sweety Bottle could easily have ended up seeming merely episodic, a string of unconnected anecdotes with no particular reason for putting them on a stage together.

The Brennans have, however, managed their raw material much more cleverly than that: from an early stage the narrative is bound together by lugubrious references to a certain Grinder McVeigh, who has torched a neighbouring shebeen for barring him. JB, owner of The Sweety Bottle, has barred him too, which could be ominous. McVeigh is a “Provie”, "a nutcase with connections", as one regular puts it, and it's possible he may be lining up The Sweety Bottle for a visit, one that would decidedly not be for social purposes.

The character of Sam is another strong binding element. A suited wide-boy to begin with, he gradually morphs into a state of heavy-drinking morosity, downing 'wall-climbers' (the local hooch) like they’re water, and watching his marriage disintegrate. In Gerard Jordan’s sensitively observed performance, Sam’s decline is painfully recorded: beneath the relentlessly upbeat waves of witticism and one-liners there’s a human being slowly and desperately falling to pieces.

Although The Sweety Bottle is not a 'Troubles play' as such, sectarianism inevitably impinges. A bomb goes off in the background at one point, there are references to knee-cappings, and to feuding between the “Provies” and the “Stickies”. The shebeen is, unsurprisingly, viewed as a refuge by its denizens, their indefatigable black humour a last line of defence against an outside world where ordinary comforts and consolations are at a premium.

The humour is sparklingly projected by a cast who revel in the Brennans’ forensic ear for local dialect. Ciarán Nolan’s John is a constant point of attention, a careening, high octane study of a wise-cracking Giro-victim, obsessively decanting money into “El Bandito”, the shebeen’s decrepit fruit machine, and fielding an incessant shower of well-meaning insults from his fellow drinkers. Father Peyton (Gordon Fulton) is another vividly imagined creation, a rollicking portrayal of a local 'character' who dresses like a priest, feigns injury at blast sites to claim compensation, and has a near-death experience with a fish supper.

Bar-owner JB and his long-suffering, toughly resourceful wife Eileen are played with insight and assurance by Marty Maguire and Carol Moore. JB is mainly a stabilising, philosophical presence in The Sweety Bottle, making his single moment of melt-down all the more disorienting.

Oiling virtually every wheel of social intercourse in The Sweety Bottle is Manolito, so-called because he allegedly resembles a character in The High Chaparral, a cowboy series from the 1960s. Lalor Roddy is the actor here, and delivers a potted masterclass in comic timing and drolly understated facial inflections. He’s the play’s heart in many ways, a wise old josser with an unquenchable hankering for 'wall-climber'. It’s a tribute to Roddy’s richly accomplished, affectionate portrayal of the character to say his Manolito would look by no means out of place in a drama by O’Casey.

The Sweety Bottle is not a play for the linguistically squeamish. The f-word (and its various cognates) is used with spectacular frequency, eliciting uncontrollable mirth from the audience on virtually every appearance. You don’t need to be particularly sensitive, I think, to occasionally find this a trifle disconcerting. The Brennans’ dialogue is, though, undeniably authentic in its clipped, flinty rhythms, and in suggesting how important a role freedom of linguistic expression, however blunt and unsophisticated, plays in conferring dignity and a sense of identity on characters hemmed in by social disadvantage, and battered psychologically by the daily ramifications of sectarian conflict.

Ciarán Bagnall’s set effectively combines drabness – a shabby sideboard is the bar counter, a clapped-out Dansette spins old dance records – with the homely parlour atmosphere which keeps the regular clientele returning. Tony Devlin directs the action zippily, differentiating sharply between the individual characters, and catching to a tee the kind of infectious, self-perpetuating banter they use to communicate with one another.

There are, it seems, no more venues like The Sweety Bottle left in Belfast: the safety they provided is no longer deemed necessary in the relatively peaceful, post-conflict environment of the twenty-first century. And so the Brennans’ play, while primarily written “to get a bit of entertainment going” (as Gerard puts it), has value also as a slice of social history, with a gentle, if unmistakable whiff of nostalgia about it.

Terry Blain is an arts journalist and cultural commentator, contributing regularly to BBC Music Magazine, Opera Britannia, Culture Northern Ireland and other publications.