There is a particular reflex that arrives with the first cold snap of October. The nights draw in, someone lights a fire, and a hand reaches, almost without thinking, for the whisky. It is a lovely ritual. It is also, this year, worth interrupting.

Because something has shifted. Walk into any decent bar and the back shelf tells a different story: aged rum, poured neat, treated with the reverence once reserved for single malt. The trade has taken to calling it the rum renaissance, and asking, only half in jest, whether rum is the new gin. As the weather turns, the better question is whether rum is the new whisky.

For years rum wore a silly hat. It was the stuff of beach bars and spiced novelty, sweet and sticky and vaguely piratical. That reputation did it no favours, and it hid a quiet truth: at the top end, aged rum can stand shoulder to shoulder with whisky, and usually for a good deal less money.

The image problem

Let us deal with the hat first. The spiced rum that fuels a thousand student parties is to proper aged rum what alcopops are to Burgundy: a distant, sugary relative that happens to share a surname. The good stuff could not be more different. It is dry, layered and slow, the sort of liquid you sip rather than shoot. Clear away the beach-bar association and what remains is one of the most expressive brown spirits on any shelf.

What aged rum actually is

Rum is sugarcane, distilled and then left to mature in oak, most often in the tropics. That last detail matters more than almost anything else. Heat speeds everything up. Where a Speyside cask dozes through a Scottish winter and loses perhaps two per cent a year to evaporation, a barrel in Barbados or Panama can surrender five or more. The spirit talks to the wood faster, harder, and comes out richer for it. A ten year old tropical rum has lived a fuller life than the number on its label suggests.

Then there is style, and here rum divides into camps. The column-still rums of Central America are the smooth talkers: soft, warming, full of vanilla, toffee and dried fig, built for easy pleasure by the fire. The pot-still rums of Jamaica and Barbados are louder and funkier, all tropical fruit and spice and a wild streak the trade politely calls hogo. Off to one side sits rhum agricole, the French-island style distilled from fresh cane juice rather than molasses. A good XO agricole such as Depaz, from Martinique, drinks almost like a fine brandy: grassy, mineral and quietly serious.

Rum versus whisky, honestly

So how does it measure up? On flavour, rum gives little away. Pour a Lagavulin 16 and a good aged rum side by side on a cold night and the rum will not embarrass itself. The Lagavulin brings its bonfire and its brine; the rum answers with warmth, sweetness and a long, unhurried finish. A sherried Highlander like the Dalmore 15 shares more with aged rum than either camp likes to admit, right down to the dried fruit and the Christmas-cake spice. Different moods, often the same league.

On price, rum tends to win outright. A fifteen year old Scotch rarely slips under three figures, while a superb aged rum can be had for the price of a decent supermarket blend. Where whisky keeps its edge is rigour. Scotch lives by a rulebook, and an age statement means the youngest drop in the bottle, no shortcuts. Rum's rules are looser and shift from island to island, which is both its romance and its catch. Learn to read the label and the bargains are extraordinary.

If you want to test the theory, start with two. A classic Barbadian blend like Mount Gay XO shows the smooth, structured end that works as happily in a glass as in a cocktail. A soft Panamanian ten year old like Rey del Istmo shows how much pleasure sits at the gentle, vanilla-laced end of the spectrum, and how little it costs to find out.

Drink it as you would a good whisky. Reach for a tulip glass rather than a tumbler, to gather the aromatics. No ice, or a single large cube if the warmth needs taming. Give it a minute in the glass before you judge it. And resist, just this once, the pull of the cola. The better the rum, the greater the insult the mixer becomes.

So, is it?

Is rum the new whisky? Not quite, and it does not need to be. Whisky is going nowhere, nor should it. But the honest answer is that aged rum has earned its place on the same shelf, at the same table, in the same heavy glass. It is whisky's warmer, more generous, less expensive cousin, and it has spent years being underestimated.

So on the next cold night, when the fire is lit and your hand drifts toward the familiar bottle, let it drift a little further along the shelf. The whisky will keep. The rum, this autumn, has something to say.