When is a martini not a martini?

Considering its status as the canon’s most iconic cocktail, it’s remarkable that the martini doesn’t have a single agreed upon recipe. Like many great drinks it comes with more of a template than exact specifications, which basically dares us to riff on the formula. Historically, this has meant altering the garnish – swapping the olive for a cocktail onion, perhaps – or adding a dash of bitters. Today, though, a whole generation of bartenders is using the martini to channel their creativity, introducing bespoke ingredients and flavour combinations to this old favourite. But just how many times can you remix the martini and still retain its essential martini-ness? Gamely, I investigate.

The almost overwhelmingly lavish Vesper Bar arrived at the Dorchester in January, boasting generously gilded decor by Martin Brudnizki and a menu from veteran bartender Lucia Montanelli. ‘As soon as we found out the name of the bar, we knew we had to have a signature Vesper on the menu,’ she tells me.