Part of what pushes a modern cocktail across the threshold to modern classic status is its ability to inspire fresh spins and reimaginings. Central to the iconic standing of drinks like the Negroni or Manhattan, after all, is their endless contributions to seemingly infinite riffs.

In this regard, the Penicillin, a mixture of Scotch, honey-ginger syrup, lemon juice and an Islay Scotch float—itself a riff on a Whiskey Sour—is undoubtedly a leader in the field. In fact, some consider it to be the most riffed-on modern classic out there, with dozens of spinoffs across the globe in every imaginable form, from frozen to hot to tall.

Some of these variations hew closely to their predecessor. The Amoxicillin, for example, simply adds a measure of yellow Chartreuse for honeyed sweetness, leaning on a smaller dose of ginger syrup for the signature zing. Sother Teague’s Powerful Baritone likewise sticks with Scotch as the base, but opts for floral Strega, herbal Becherovka and Montenegro, finished with a mist of peated Scotch.

Others channel the essence of the drink into different formats altogether. Perhaps the most famous example in this category is the Penichillin, a frozen rendition created by the team behind Attaboy and Milk & Honey, where the original Penicillin first took flight. At Brooklyn’s Diamond Reef, where the frozen drink was invented, it’s pulled from a slushy machine, but it can easily be whipped up in a blender, just don’t forget to float the Islay Scotch right before serving for a punch of peaty aroma. 

Amanda Victoria, meanwhile, takes the opposite approach. With the addition of warm apple cider to the expected Scotch, honey and lemon, she turns the smoky, spicy cocktail into a winter-ready update in her Hot Penicillin. A topper of ginger beer adds a spiced kick and a hint of effervescence. Ol’ Poet’s Smoke takes yet another tack, stretching the drink into a long format with the addition of Montenegro amaro and, of course, soda water. Given its tall stature, it might not resemble the modern classic at first glance, but as critic Robert Simonson observes of the drink: “It’s what a Penicillin would be if it were a highball.”