With this tale of single malts, second chances and multiple miscreants, Ken Loach and Paul Laverty distil much to warm the heart from what first looks like an unyieldingly hard Scottish cask.
Walking the line between Trainspotting and Whisky Galore!, it sees young repeat offender Robbie (Brannigan) spared prison on the proviso that he ends his violent ways and does right by his girlfriend Leonie and new baby.
With various thugs - including Leonie's dad - 'advising' him to get out of Glasgow, Robbie finds a pragmatic ally in his community service supervisor Harry (John Henshaw).
Thanks to Harry, he develops a connoisseur's taste for whisky, sharing his appreciation with fellow wrong 'uns Rhino (William Ruane), kleptomaniac Mo (Jasmine Riggins) and Albert (Gary Maitland), a very special case who, it's clear from the start, is a few nips short of a bottle.
On a tasting trip to Edinburgh, they learn that a barrel of the best stuff is about to go under the hammer in the Highlands - for at least half a million quid.
So with a plan cast in iron (Bru), Robbie leads the gang on a merry hike to siphon off what they consider to be "the angels' share" (the percentage of a barrel that is always lost through evaporation).
'Social realism' is such a dull term, but Loach and Laverty's stories ring truer than most because they have no qualms about showing characters at their best and worst (except the police, for whom only the latter ever seems to apply).
Thus, before the larks begin, we experience in sobering detail the consequences of Robbie's violent legacy, both past and present.
But the hard yards of this first act make the second so much sweeter as the lad undergoes a reformation, if not total redemption. In fact, you get the sense that none of the ne'er-do-wells will remain on the straight and narrow for very long.
With support from two of British acting's unsung heroes - the brilliant Henshaw (think Jim Royle without the catchphrases) and Roger Allam (as a sly whisky collector) - Loach once again draws exceptional performances from a cast of unknowns.
Newcomer Brannigan - an ex-jailbird himself - is a real find, though his solemn weight is splendidly countered by the scene-stealing Maitland who provides one of the film's two unforgettable, can't-believe-he-did-that moments.
Actually, make that three, since Albert's theory on the psychological effects of kilts on the higher classes proves that even a stopped clock tells the right time twice a day. Canny stuff.