This Frozen Penicillin Recipe Is the Cure for Mid-Aughts Nostalgia

The year was 2005 and bartenders were nose deep in cocktail books. “I was happier to find an old recipe and give that some shine or adapt it rather than just snatching one out of thin air,” says bartender and restauranteur Dan Greenbaum. “We were looking for hidden jewels.”

Greenbaum’s former business partner, Sam Ross, was doing just that at the subterranean West Village bar Little Branch. While he was tinkering with variations on a classic whiskey sour, the owner of Compass Box Whisky came in with some Scotch and the nutty, caramel-like qualities of the Peat Monster added complexity to Ross’s simple formula of honey, lemon, and ginger. And the Penicillin was born.

“The fact that those flavors are curative and familiar, but you just add a twist of smokier whisky really speaks to that moment and Sam and the ethos of the time,” Greenbaum says. “No one had done it on paper, but it felt like it had been a classic for years.”

So when the two bartenders (plus Michael McIlroy) opened up the tropical bar Diamond Reef in Bed-Stuy, Brooklyn, they brought the Penicillin with them. Using the same ingredients, but tweaking the ratio a bit, they made a frozen version to put inside their Frosty Factory machines, and came up with the “cheeky” name Penichillin. To add to the playful spirit, Greenbaum found Kikkoman soy sauce bottles and poured a Scotch floater out of them right before serving.

“The idea behind the bar was to put out drinks very fast in a bit of a rowdy atmosphere on the patio,” he remembers. “By putting the Penicillin in the frozen machine, it bridged the gap between this serious cocktail bar and a tropical, fun environment.”

A commercial slushie machine isn’t necessary to recreate that vibe at home. Just break out the blender and play with your ratios, Greenbaum advises. “The rule of thumb with frozen drinks is to up the sweetener a little bit because you perceive something as dryer when it’s ice cold,” he says. Start with three-quarters of an ounce of honey-ginger syrup to two ounces of Scotch and a scoop of crushed ice, and then taste along the way.

Even though Diamond Reef closed in 2021, the Penichillin remained a top-seller until the very end. And its predecessor can be found on menus around the world, has become a modern classic in its own right, and is something that cocktail aficionados make a pilgrimage to New York to experience. 

“The drink changed so many people’s minds about Scotch,” Greenbaum says. “Even a mediocre Penicillin is more interesting than most drinks.”

Frozen Penicillin Recipe

Serving: 1

Ingredients:

2 ounces blended Scotch whisky (or black tea, to make it N/A)
¾ ounce honey-ginger syrup (see below)
¾ ounce lemon juice
¼ cup ice
Peated Scotch whisky (or lapsang souchong as the float, to make it N/A)

Instructions:

Step 1: In a blender, combine the first four ingredients and blend until smooth.

Step 2: Pour into a footed Irish whiskey glass.

Step 3: Gently pour the peated whiskey on top of the drink.

Step 4: Serve with a straw and garnish with a paper parasol.

Honey-Ginger Syrup Recipe

Ingredients: 

8 ounces honey
1 (6-inch) piece of ginger root, peeled and sliced
8 ounces water

Instructions:

Step 1: Combine the honey with the ginger root and water in a small pot and bring to a boil. Reduce the heat and simmer for five minutes. Refrigerate overnight, then strain, discarding the solids.

Dina Ávila is a photographer living in Portland, Oregon.
Recipe tested by Ivy Manning