Before the mojito, before the caipirinha, the gin and tonic reigned supreme as a hot-weather drink, quenching summertime thirsts at taverns and backyard parties the world over. Born of practicality — the quinine in the tonic once helped combat malaria in the British Empire, while the gin made it easier for authorities to throw the bitter elixir down people’s throats — it survived simply as a delectable liquid marriage.

Although more complicated drinks might be the tipples of choice for today’s drinkers, the seemingly elementary G&T is enough of a classic to provoke debate on how best to serve it up. Favored gin-to-tonic ratios vary from 1-to-1 to 1-to-4. Britishers prefer lemon as a garnish, while Americans go for the more familiar lime wedge, which some simply shove into the glass, while others squeeze it over the drink. And then there’s the question of tonic choice.

In testing how six gins (three classics, three newer brands) performed in a gin and tonic, a recent tasting panel opted for one part gin to two parts tonic, poured into a glass filled to the brim with ice and topped with a squeezed lime wedge. While new boutique tonics such as Q and Fever-Tree are preferred by many professionals in lieu of mass-market items such as Canada Dry, they’re not always readily available to the average consumer, who might not live or work near a Whole Foods (but they could be worth a trip, as Charlotte Cowles writes today). Our control tonic: small, individual bottles of Schweppes, to ensure a fresh pour.

On the panel were myself; a cocktail historian and author of “Imbibe!” (Penguin), David Wondrich; a former bartender at Pegu Club and a spirits journalist, St. John Frizell, and mixologist and bar owner Julie Reiner, whose new Brooklyn saloon, the Clover Club, provided the setting for the tasting.