Roseisle is one of Scotch whisky's best-kept secrets. Built by Diageo in 2009 on the site of an existing maltings complex near Elgin, it is one of the most modern and technically sophisticated distilleries in Scotland — capable of producing 12.5 million litres of pure alcohol per year, making it one of the largest in the country. Despite this scale, Roseisle almost never appears as a single malt; the vast majority of its output disappears quietly into Johnnie Walker blends. The Diageo Special Releases programme offers one of the very few opportunities to taste it in pure, unblended form. Its architectural steel-and-glass aesthetic could not be further from the romantic image of Highland distilling — yet the whisky inside is anything but industrial.

Oban occupies one of the most dramatic positions in Scotch whisky. The distillery sits directly on the harbour front of the town of Oban — the gateway to the Western Isles — with the distillery buildings pressed against a sheer cliff face on one side and the quayside on the other. There is no room to expand; what you see is what there is. Founded in 1794 by the Stevenson brothers, Oban predates the town itself. Its geographic position — on the boundary between the mainland Highlands and the island world beyond — gives its whisky a character that defies easy categorisation: part Highland, part maritime, part island. This 10-year-old cask strength special release is rarer and rawer than the famous 14-year-old, showing the distillery's character with the volume turned up.

Caperdonich is a ghost. The distillery in Rothes, Speyside, was built in 1897 as a twin to the adjacent Glen Grant, sharing its water source and originally piping new-make spirit directly between the two through an overhead pipe. It was mothballed in 1902 after just five years, reopened in 1965, and finally demolished in 2010 — the site is now a housing development. No more Caperdonich will ever be made. Every existing bottle represents a finite, diminishing supply of spirit from a distillery that no longer exists. The SMWS bottling "Chestnut Forest Confections" is from a single cask laid down in the 1990s and bottled at natural strength after a quarter century of patient maturation. This is whisky as archaeology.

Glen Scotia occupies a melancholy and magnificent corner of whisky history. Campbeltown, a small town on the tip of the Kintyre Peninsula in Argyll, was once the whisky capital of the world. In the late 19th century, over thirty distilleries operated within the town boundaries. Today there are three. Glen Scotia, founded in 1832, is one of the survivors — and one of the most characterful. Its whiskies carry the hallmarks of Campbeltown's distinctive style: saline, coastal, briny, with a slight medicinal or tarry quality that comes from the town's long industrial maritime heritage. The SMWS single cask "Surf, Sea and Shore" at 60.4% is Glen Scotia at its most unvarnished and expressively coastal — a dram that divides opinion and commits entirely to a specific sense of place.

Knockdhu distillery in Aberdeenshire, founded in 1894, produces whisky marketed under the An Cnoc label — the Gaelic for "the hill" that rises behind the distillery. In ordinary circumstances it is a pleasant and approachable Highland malt: lightly fruity, gently honeyed, unchallenging. The SMWS has a gift for finding the extraordinary outliers within a distillery's production — single casks that, through the alchemy of a specific barrel and a specific decade of maturation, have developed flavours that nobody planned and nobody could replicate. "Jamaican Oxtail Stew" is precisely such a cask. The SMWS tasting panel names each cask after tasting blind — their names are never arbitrary. They tasted this one and thought: Sunday roast. Braised meat. Caribbean spice. They were correct.

Glen Garioch — pronounced "Glen Geerie" — is one of Scotland's oldest distilleries, established in 1797 in the small market town of Oldmeldrum in Aberdeenshire, making it one of the most easterly in the country. It occupies a curious position in the whisky landscape: well-regarded by those who know it, largely unknown to those who don't. The distillery famously used its waste heat to warm the local greenhouses, growing tomatoes and vegetables for the town — a piece of industrial ingenuity that speaks to its pragmatic, community-rooted character. Fifteen years in sherry casks at cask strength brings Glen Garioch to its most imposing and generous expression — a whisky that rewards patience and rewards those who seek it out.

The North British Distillery in Edinburgh is one of the great invisible engines of the Scotch whisky industry. Founded in 1885 by a group of blenders — including the Distillers Company and John Haig — it was designed from the outset to produce grain whisky at industrial scale for blending. It has been doing exactly that ever since, from its site in the Gorgie district of Edinburgh, producing wheat-based spirit in continuous column stills. Nobody ages North British grain whisky for 26 years. It is not done. It is a blending component, a workhorse, a background presence. Lady of the Glen — a small independent bottler with a gift for finding extraordinary forgotten casks — found this one and had the courage to bottle it. What 26 years does to a grain whisky is the question tonight's penultimate dram answers.

Bruichladdich occupies a unique position on Islay's northern shore — an intensely independent, philosophically driven distillery that reopened in 2001 after years of mothballing, and has spent the two decades since doing things entirely on its own terms. Octomore is its most extreme statement: the most heavily peated Scotch whisky produced anywhere on earth. For context, Ardbeg Ten — itself considered extremely peaty — measures around 55 parts per million of phenols. Octomore 16.1 is approximately 197 PPM — roughly four times that level. Bruichladdich's radical belief is that super-heavy peat demands exceptional whisky underneath it; the spirit must be good enough to carry the weight of the smoke. The 16.1 is evidence that they are correct.