The Sazerac may have been the world’s first cocktail but it wasn’t mine. Two decades in to my fitful but focused programme of spirit-based research, the barman at the Cat and Mutton on Broadway Market rinsed a glass with absinthe, poured in cognac, rye and two kinds of bitters and handed it to me like he was doing me a favour.

I didn’t have a problem with what was in the glass but I did with what had just left it. I’m afraid of absinthe. It’s one of the drawbacks of a degree in French literature; a lesser one, perhaps, than unfitness for gainful employment but an issue nonetheless. You can’t spend years reading the hallucinogenic poetry of Baudelaire or the delicately vicious stories of Maupassant and learning about their love of absinthe and their early, raving deaths without conflating the two. Absinthe is known as “the green fairy” but she’s the newborn-cursing (rather than wish-granting) kind. It’s no good pointing out that both writers died of syphilis. I’m a literature graduate, unhindered by scientific imperatives. For all I know, you catch syphilis from drinking absinthe, too.

A fearsome, raving death notwithstanding, the drink looked interesting and had a pretty name; and I’m quite brave when there’s alcohol in the offing. Reader, I drank it, and it was delicious – complex, pungent, with a liquorice bite. Legend has it that the pharmacist Antoine Peychaud invented the cocktail in 1830s New Orleans as a toddy for sick friends by mixing Sazerac de Forge et Fils cognac and his home-made bitters and, if the legend is right, no wonder it caught on. The brandy was swapped with rye whiskey when the phylloxera louse destroyed France’s vineyards; later, when the Cognac region was once again able to distil grapes, some bright spark started to include both spirits.

I’m not sure when the green fairy waved her wand over the concoction but her malign influence is apparent in that whisper of liquorice, to say nothing of my fierce hankering for another delicious, pernicious sip. I should have paid more attention to those 19th-century Frenchmen of letters. Here’s Gustave Flaubert on absinthe in his Dictionary of Received Ideas: “Ultra-violent poison; one glass and you’re dead. Journalists drink it while writing their articles. Has killed more soldiers than the Bedouins.” You have to admire a liquor that brings out the humorist in the author of Madame Bovary.

So I wound up in Spuntino, a bar in Soho – surely the patch of London that has the most affinity with convulsion-inducing liquors, to say nothing of syphilis – being shown how to make a Sazerac by the bartender Benny Locke. I may be preoccupied with absinthe; he’s obsessed with bourbon. Odd, really: no one ever banned bourbon specifically, as the French did absinthe, claiming it makes one crazy and criminal and provokes everything from epilepsy to tuberculosis.

Still, bourbon – corn liquor aged in charred oak casks – is delightful, sweeter than the spicy rye whiskey, and Benny drinks and creatively adulterates it, steeping fresh buttered popcorn in it and removing the fat with a strainer. His preoccupation has filled Spuntino with unusual takes on what was once moonshine for Southern farm boys, from high-end incarnations such as Van Winkle (which can go for over £350 a bottle) to Kings County, made in New York.

Benny holds bourbon cocktail-making classes at which you, gentle reader, can discover the allure of the Sazerac, so great that in 1919, F Scott Fitzgerald took a pitcher of it more than 250 miles from New Orleans to Montgomery to celebrate an important occasion. He doesn’t name the occasion; perhaps he couldn’t remember. The Sazerac, which now comes rinsed in a poison beloved of diseased intellectuals, was invented to heal the sick. Its creator did not specify of what.