The Penicillin: A Complete History & Classic Recipe

Smoky, soothing, and perfectly balanced between sweet and sharp, the Penicillin is the modern classic that revived Scotch whisky’s relevance behind the bar. With its blend of smoky Scotch, honey-ginger syrup, and lemon juice, it’s equal parts comfort and sophistication — a curative cocktail for the weary and the wise.

Created in the 21st century but rooted in the craft and spirit of pre-Prohibition balance, the Penicillin has earned a permanent place alongside century-old icons like the Sour, the Old Fashioned, and the Manhattan.

I. Origins

The Penicillin was created in 2005 by Sam Ross, a young Australian bartender working under Sasha Petraske at New York’s legendary Milk & Honey, the bar that defined the modern cocktail revival.

Ross wanted to create a drink that captured the comforting warmth of a hot toddy but with the structure and balanceof a professional cocktail. Drawing inspiration from the Whiskey Sour and the Gold Rush, he combined blended Scotch with a house-made honey-ginger syrup and fresh lemon juice — then added a float of smoky Islay whisky on top.

The result was revolutionary: a drink that was simultaneously spicy, sweet, tart, and smoky, like a cure for whatever ailed you.

He named it the “Penicillin” as a tongue-in-cheek reference to its supposed restorative powers. Within months, it became the house favorite — and within years, it became a global phenomenon.

II. Historical Evolution

The 2000s – The Birth of a Modern Classic

When the Penicillin appeared on Milk & Honey’s menu, it was part of a new movement that valued fresh ingredients, historical technique, and elegant restraint.

Bartenders loved it because it was deceptively simple but brilliantly balanced. Guests loved it because it was approachable — a Scotch cocktail that wasn’t intimidating.

Ross’s combination of two whiskies (blended for body, peated for aroma) was groundbreaking. It taught a new generation that Scotch could be as versatile as bourbon or gin.

The 2010s – The Global Spread

By 2010, the Penicillin had spread to cocktail bars around the world. It became a litmus test for bartenders — if you could make a great Penicillin, you understood balance, texture, and flavor layering.

It also marked a cultural shift: the acceptance of Scotch in mixed drinks. Before the Penicillin, most Scotch was served neat or with ice; after it, Scotch cocktails became a respected art form again.

The 2020s – The Legacy Era

Today, the Penicillin is one of the few “new” drinks to be universally considered a modern classic. It’s listed alongside century-old icons and studied in professional bar programs worldwide.

It’s not just a cocktail — it’s the blueprint for how to create something timeless in a modern world.

III. Ingredients & Technique

The Penicillin is all about balance through contrast — fiery ginger against smoky Scotch, bright lemon against rich honey, spice against silk.

Core Components

• Blended Scotch: The backbone — rich but smooth, typically 12-year.

• Islay Scotch (peated): Used as a float; smoky, briny, and aromatic.

• Lemon Juice: Provides the tart structure.

• Honey-Ginger Syrup: Sweetness with heat — the cocktail’s heart.

Honey-Ginger Syrup Recipe

• 1 cup honey

• 1 cup water

• 3–4 inches fresh ginger, slicedBring all to a simmer for 10 minutes, strain, and cool.

The Classic Ratio

• 2 oz (60 ml) blended Scotch

• 0.75 oz (22 ml) fresh lemon juice

• 0.75 oz (22 ml) honey-ginger syrup

• 0.25 oz (7 ml) Islay Scotch (float)

IV. Cultural Significance

The Penicillin is often called “the cocktail that cured modern mixology.”

It represents the rebirth of craft, storytelling, and restraint in cocktail design. In an era when many bartenders were experimenting with overly complex drinks, Ross’s creation reminded everyone that true innovation lies in simplicity and precision.

It also symbolizes the democratization of Scotch — a spirit once reserved for connoisseurs and cigar lounges, now made approachable, accessible, and deeply comforting.

Culturally, it bridges worlds: the warmth of a toddy, the acidity of a sour, and the smoky mystique of an Islay dram. It’s a drink that feels both ancient and modern, medicinal and indulgent.

V. How to Make the Classic Version Today

Recipe — The Classic Penicillin

Ingredients

• 2 oz (60 ml) blended Scotch whisky

• 0.75 oz (22 ml) fresh lemon juice

• 0.75 oz (22 ml) honey-ginger syrup

• 0.25 oz (7 ml) Islay single malt Scotch (for float)

Method

1. Add blended Scotch, lemon juice, and honey-ginger syrup to a shaker with ice.

2. Shake until chilled (about 10 seconds).

3. Strain over fresh ice in an Old Fashioned glass.

4. Gently float the Islay whisky on top by pouring it over the back of a spoon.

5. Garnish with candied ginger or a lemon peel.

Specs

• Glass: Rocks or Old Fashioned

• Ice: Cubed

• Garnish: Candied ginger or lemon peel

• Style: Scotch sour with aromatic float

Technique Notes

• Use a good blended Scotch (like Monkey Shoulder or Famous Grouse).

• The float is key — it adds aroma and depth.

• Make the syrup fresh; the ginger’s potency fades after 48 hours.

Variations & Lineage

• Mezcal Penicillin (a.k.a. Oaxacan Cure): Substitute mezcal for Scotch.

• Gold Rush: Bourbon, honey syrup, lemon — the Penicillin’s precursor.

• Penicillin Sour: Serve up, coupe style, without float.

• Hot Penicillin: Add hot water for a toddy-style version.

Service & Pairing Tip

• Perfect for autumn or winter evenings.

• Pairs beautifully with smoked salmon, roasted nuts, or honey desserts.

VI. Modern Variations & Legacy

The Penicillin is now taught in bartending schools and featured in nearly every major cocktail compendium. It’s one of the few modern drinks to have achieved the status of a “new classic.”

Its genius lies in the details: a dual-Scotch build, a house syrup with natural spice, and the idea that modern cocktails can still feel timeless.

It also inspired an entire generation of bartenders to explore whisky beyond its neat form — to treat it as an ingredient, not just a drink.

As Sam Ross himself once said:

“I wanted to make something that felt like it had always existed.”

He succeeded. The Penicillin tastes eternal — smoky, sweet, curative, and unforgettable.