My nephew Mickey Ehrlich, of Brooklyn, New York, has, once again, proven his good sense by developing a taste for Gimlets. I discovered this at a supermarket in the suburbs of New York, where I was shopping with the young man's father. Strolling down the aisle filled with soft drinks of every description, many of them highly questionable, my brother picked up a bottle of Rose's Lime Juice. "Why does he want that?" I asked. That's when I heard the news about Gimlets.

If memory serves, I have never seen anyone order a Gimlet in a bar. And I know that I had never tasted or made one. So Mickey's new cocktail preference gave me the chance to familiarise myself with the drink by making them, and tasting them, and doing a little experimentation. I enjoyed every aspect of the venture, even though I didn't have the faintest idea how to make the things.

Fortunately, it's not too easy to go woefully wrong: a Gimlet has just two ingredients, gin (or vodka) and Rose's. If you end up with too much of one, you add more of the other till you've reached Gimlet heaven. In our case, the proceedings began with two parts gin to one part Rose's. That seemed too strong to Mick, so I brought it up to equal parts gin and Rose's. He seemed content there, though eventually he decided on a slightly bigger dose of lime, making it probably five parts Rose's to four parts gin. And I liked the drink that way, too. It should be noted, however, that this was export-strength Beefeater (47 per cent alcohol); with gin at 40 per cent, less Rose's would probably have been right.

When I got home to my cocktail books, I discovered that the rest of the world differs considerably on the right way to make a Gimlet. Most authorities say it should be stirred with ice and then strained into a Martini glass. All prescribe a lime wedge as a garnish. But on the matter of proportions, there is nothing but disagreement. Some use as little as one part Rose's to four parts gin, others go up to evens, and there's a high occupancy rate in all sectors of the territory in between. The message is clear: experiment, and find your own way.

Like most of the classic cocktails, the Gimlet has disputed origins. It seems to have a connection with the British Navy, for which Rose's was invented some time around 1867 as a convenient way of storing the lime juice needed to ward off scurvy. The official-ish story is that Rose's was mixed with gin to make it more palatable. One version of the name's origin connects it with the gimlet, a small drill used to access the contents of the wooden barrel in which the mixture was stored. The other story connects it with Sir Thomas D Gimlette, a Navy surgeon, who supposedly devised the concoction. This is one of those things we'll probably never know for sure.

We do know, however, that a drink resembling the modern version was mentioned in print in 1928. We also know that Raymond Chandler, who knew more about alcohol than was good for his health, had his character Philip Marlowe extol the drink in his 1954 novel The Long Goodbye. "A real Gimlet is half gin and half Rose's lime juice," said Marlowe, "and nothing else. It beats Martinis hollow."

I don't agree with Marlowe about the superiority of Gimlets over Martinis, but I do know that they're a fine drink. And you can do something extra with them to good and moderating effect: make the drink by stirring it in a tall glass, then top with fizzy water. This turns the drink into a species of Collins, with a nod to the Gin Rickey. It enhances the drink's refreshing qualities and gives it the same alcoholic strength, approximately, as a glass of wine. It won't take your head off and you won't get scurvy, either.

Three Fragrant Whites

Forrest Gewürztraminer 2004, Marlborough (£9.99, Adnams, 01502 727 222, A lush rendition of New Zealand Gewürztraminer: abundant spiciness, loads of exotic fruit flavours, classic lychee sweetness balanced by good acidity.

Les Jamelles Viognier 2004, Vin de Pays d'Oc (£3.99 from £4.99 until 20 August, Co-Op) Needs drinking soon but still drinking very well. A good peachy example of pure Viognier character. Great price.

Quinta de Azevedo Vinho Verde 2005 (£5.49, Majestic) Newest vintage of an old favourite of this column. Delectable citrus, light touch of spritz, freshness all round. Good apéritif wine.