The best part of dinner is often the bit after dinner. The plates are cleared, the candles have burned down an inch, and nobody has any intention of leaving. This is amaro's hour. Somewhere in Italy a bottle of something dark and bittersweet is being poured into small glasses right now, and the table has gone quiet in the good way. Learning how to drink amaro is really learning how to make a good evening last a little longer.

Amaro simply means bitter in Italian, which undersells it enormously. These are herbal liqueurs built from roots, bark, citrus peel and spices, macerated in spirit, sweetened just enough to keep the bitterness charming rather than punishing, and often rested in oak before bottling. Nearly every Italian region has its own, most recipes are guarded like family jewels, and no two taste quite alike. Some are gentle and orange-scented. Some could strip paint. All of them were designed for the moment the eating is done.

For years amaro was the drinks world's private joke: the thing bartenders drank after service, the dusty bottle an Italian friend's grandmother produced with suspicious enthusiasm. That has changed. Bitter is back, and rightly so. The same palate that fell for the Negroni and the spritz has worked out that the bittersweet register runs far deeper than one orange aperitivo, and amaro is where it gets genuinely interesting.

So what actually is an amaro?

The category is broad enough to be almost useless as a description, which is part of the charm. At the light end sit soft, citrus-led amari you could pour before dinner as happily as after. At the far end live the fierce, medicinal bottles that taste like a very persuasive herbal remedy and are all the better for it. What unites them is a backbone of bitterness, usually drawn from gentian root, wormwood or cinchona bark, held in balance against sugar and a small forest of aromatic botanicals. Strengths run from around sixteen per cent to the high thirties, so it pays to know roughly where a bottle sits before you pour a generous measure.

From gentle to ferocious: where to start

If you are new to all this, begin soft and work your way in. Amaro Montenegro is the great gateway, and it has converted more sceptics than any bottle on the shelf. Made in Bologna to a recipe Stanislao Cobianchi drew up in 1885, it folds around forty botanicals into something warm and perfumed: orange oil, dried herbs, a whisper of vanilla and nutmeg, with the bitterness kept on a light leash. At twenty-three per cent it is a rounded, easy sipper, the amaro that even people who insist they dislike amari tend to fall for.

Then, when you are ready for the deep end, there is Fernet-Branca. Bartenders call it the industry handshake, the shot poured at the end of a long shift that separates the curious from the committed. Made in Milan by the Branca family since 1845, it packs twenty-seven botanicals, among them aloe, gentian, rhubarb, myrrh and saffron, into a bracing rush of menthol, eucalyptus and dark bitter herbs. At thirty-nine per cent it does not meet you halfway. It expects you to come to it, and once it clicks, nothing else quite scratches the same itch.

Between those two poles sits everything else: the coffee-and-cola darkness of a Sicilian amaro, the grappa-based elegance of a Piedmontese one, the caramel-sweet crowd-pleasers that slip down after a long lunch. Find your Montenegro and your Fernet first, learn where your own taste lands between them, and the rest of the map more or less draws itself.

How to serve it

Amaro asks almost nothing of you, which is a large part of its appeal. The classic serve is neat, at room temperature or lightly chilled, in a small glass, sipped slowly while the conversation carries on around it. A bracing one like Fernet is best straight from the freezer, poured into a chilled glass so the cold folds the ferocity into something almost silky. If you want it longer and cooler, a single large cube in a tumbler stretches it out without washing away the character.

From there the possibilities open up. A softer amaro makes a superb, low-effort spritz: two parts amaro, three parts soda, plenty of ice and a slice of orange, and you have the thinking drinker's answer to the Aperol spritz for the weeks when the weather turns. Fernet has its own long serve, the Fernet con Coca, mixed with cola over ice, which Argentina drinks with such devotion that it is practically a national pastime. And a single dash of amaro will quietly improve half the cocktails you already love.

Which brings us to the only real decision, which is which bottle to open first. Start gentle, keep something bracing in reserve, and you have the entire spectrum covered from one small shelf. These two are the perfect place to begin, and the perfect place to graduate to.

When to reach for it

Amaro is autumn's natural companion. As the evenings draw in and dinner becomes a longer, slower affair, the bittersweet works in a way it never quite does in July. It is the host's quiet flourish, the bottle produced without ceremony once the pudding plates are gone, the one that says stay a while. It has form behind the bar, too: Italian bitters are the beating heart of the Negroni and the Boulevardier, so if you have enjoyed either, you already like this more than you realise. Drinking amaro neat after dinner is simply meeting it without the disguise.

So pour a small measure, no more than fifty millilitres, into a glass that feels good in the hand. Let the first bitter note arrive, then the sweetness that follows behind it, then the long warm finish that trails you into the rest of the evening. The candles are low, nobody is leaving, and the best part of dinner has only just begun. That is how to drink amaro, and the turning weather is exactly the moment to learn.