Penicillin Cocktail Recipe: Modern Classic

If you're searching for a cocktail that's equal parts soothing and invigorating, the Penicillin cocktail is your prescription. This modern classic has earned its place alongside timeless drinks like the Old Fashioned and Negroni, offering a complex interplay of sweet honey, bright citrus, warming ginger, and smoky scotch that truly does cure what ails you.

Created in 2005 by bartender Sam Ross at the legendary Milk & Honey in New York City, the Penicillin cocktail revolutionized how we think about scotch in mixed drinks. Rather than relying on the traditional scotch and soda template, Ross crafted something entirely new: a sophisticated blend that showcases scotch's versatility while introducing layers of flavor that appeal to both whisky enthusiasts and cocktail newcomers alike.

The Classic Penicillin Cocktail Recipe

The beauty of the Penicillin lies in its precise balance of four distinct flavor profiles. Each ingredient plays a critical role in creating the drink's signature character.

Ingredients:

• 2 oz blended scotch whisky
• 0.75 oz fresh lemon juice
• 0.75 oz honey-ginger syrup
• 0.25 oz Islay single malt scotch (for the float)
• Candied ginger for garnish

Instructions:

1. Add blended scotch, lemon juice, and honey-ginger syrup to a cocktail shaker
2. Fill with ice and shake vigorously for 15 seconds until well-chilled
3. Double strain into a rocks glass over fresh ice
4. Gently pour the Islay scotch over the back of a bar spoon to create a float
5. Garnish with a piece of candied ginger on a cocktail pick

The result is a drink that greets you with intense smoky aromatics, transitions to sweet and spicy flavors mid-palate, and finishes with bright citrus notes.

Making Honey-Ginger Syrup: The Heart of the Penicillin

The honey-ginger syrup is non-negotiable for an authentic Penicillin cocktail. While you might be tempted to use plain honey syrup, the fresh ginger adds a spicy warmth that's essential to the drink's character.

Honey-Ginger Syrup Recipe:

• 1 cup honey
• 1 cup water
• 6-inch piece of fresh ginger, sliced (no need to peel)

Method:

1. Combine honey and water in a saucepan over medium heat
2. Stir until honey dissolves completely
3. Add sliced ginger and bring to a gentle simmer
4. Reduce heat and let steep for 15-20 minutes
5. Remove from heat and let cool completely
6. Strain out ginger pieces and bottle
7. Store in refrigerator for up to 2 weeks

The longer you steep the ginger, the spicier your syrup becomes. Start with 15 minutes for a milder profile, or push to 30 minutes if you want serious ginger heat.

Selecting Your Scotch: A Two-Whisky System

The Penicillin's genius lies in using two different scotch whiskies, each serving a distinct purpose in the final drink.

The Base: Blended Scotch

For the base spirit, choose a quality blended scotch that's smooth and approachable. Popular choices include:

• Famous Grouse
• Monkey Shoulder
• Compass Box Great King Street
• Johnnie Walker Black Label

Avoid heavily peated or intensely flavored scotches for the base. You want something that provides a solid whisky foundation without overwhelming the honey and ginger notes.

The Float: Islay Single Malt

The Islay float is what transforms a good cocktail into something extraordinary. This small measure of intensely smoky, peated scotch sits atop the drink, hitting your nose with every sip.

Classic Islay choices include:

• Laphroaig 10 Year (medicinal, maritime)
• Ardbeg 10 Year (powerful, bold)
• Lagavulin 16 Year (rich, refined)
• Caol Ila 12 Year (balanced, approachable)

Even a quarter ounce makes a dramatic impact, so invest in a good bottle. It will last you through many rounds of Penicillins.

Mastering the Islay Float Technique

The float isn't just for show. It's a critical technique that creates the Penicillin's signature aromatic experience. When executed properly, the Islay scotch forms a distinct layer on top of the drink, meaning the first thing that hits your nose is that gorgeous smoky, peaty aroma.

How to Float Like a Pro:

1. Pour the main cocktail first and add ice
2. Hold a bar spoon upside down just above the drink's surface
3. Very slowly pour the Islay scotch over the back of the spoon
4. The liquid should gently cascade down, spreading across the top
5. Don't stir. The layers should remain distinct

As you sip, the float gradually mingles with the base cocktail, creating an evolving flavor experience from first sip to last.

The History: Sam Ross and Milk & Honey's Modern Classic

In 2005, legendary bartender Sam Ross was working at Milk & Honey, the influential speakeasy-style bar founded by Sasha Petriske in New York's Lower East Side. Milk & Honey had already established itself as the epicenter of the modern cocktail renaissance, emphasizing craft techniques, quality ingredients, and classic recipes.

Ross wanted to create something that honored scotch's complexity while making it accessible to a broader audience. Drawing inspiration from the Gold Rush (bourbon, honey, and lemon) and the whisky sour template, he added his own innovations: honey-ginger syrup for complexity and warmth, and the Islay float for dramatic aromatics.

The name "Penicillin" perfectly captured the drink's restorative, almost medicinal qualities. The combination of honey (traditionally soothing), ginger (warming and healing), and lemon (vitamin C-rich) evoked the feeling of a remedy, while the smoky scotch added sophisticated depth.

The cocktail became an instant hit at Milk & Honey and quickly spread to bars worldwide. By 2010, it was appearing on cocktail menus from London to Tokyo. Today, the Penicillin is recognized as one of the most important cocktail innovations of the 21st century, regularly appearing on "Modern Classics" lists and in professional bartending competitions.

If you're interested in exploring more scotch-based cocktails, check out our comprehensive guide to scotch cocktails for additional recipes and mixing techniques.

Why the Penicillin Works: The Four-Flavor Balance

The Penicillin's enduring appeal comes from its masterful balance of four distinct flavor elements:

Sweet: The honey provides natural sweetness that's richer and more complex than simple syrup. It coats the palate and mellows the whisky's edges.

Sour: Fresh lemon juice adds brightness and acidity, cutting through the honey and preventing the drink from becoming cloying. Always use fresh lemon juice, never bottled.

Spicy: Fresh ginger brings warmth and a subtle heat that builds with each sip. It bridges the sweet and sour elements while adding its own dimension.

Smoky: The Islay float delivers intense peat smoke aromatics that transform the entire drinking experience. This top note makes the Penicillin unmistakable.

This four-part harmony creates a cocktail that's simultaneously comforting and exciting, familiar yet exotic. Each sip reveals different layers as the flavors evolve on your palate.

Technique Tips for the Perfect Penicillin

While the Penicillin appears straightforward, a few technique refinements will elevate your results:

Shake with Purpose: Shake vigorously for a full 15 seconds. The honey-ginger syrup is thick and needs aggressive shaking to properly integrate and chill the drink.

Double Strain: Always double strain through a fine mesh strainer to remove ice chips and any ginger particles. This creates a smooth, refined texture.

Fresh Ice for Serving: After shaking, always pour over fresh ice in your serving glass. The ice from shaking has already started melting and diluting.

Candied Ginger Garnish: This isn't just decorative. The candied ginger provides a sweet, spicy bite between sips that perfectly complements the drink. Skewer it on a cocktail pick for easy eating.

Temperature Matters: Serve the Penicillin ice cold. The contrast between the chilled base and the aromatic float creates the optimal tasting experience.

Penicillin Variations to Explore

Once you've mastered the classic, these variations offer new perspectives on the template:

Oaxacan Penicillin

Replace the scotch with mezcal for a smokier, more agave-forward version. Use 2 oz mezcal as the base and float 0.25 oz of a smokier mezcal variety on top.

Kentucky Penicillin

Substitute bourbon for the blended scotch and use a high-rye bourbon or rye whiskey for the float. This creates a spicier, sweeter profile that's distinctly American.

Penicillin No. 2

Add 0.25 oz Islay scotch to the shaker (instead of floating) and float 0.25 oz Chartreuse instead. This variation appeared shortly after the original and has its own devoted following.

Winter Penicillin

Increase the ginger in your syrup for extra heat and add a dash of Angostura bitters to the shaker. Perfect for cold weather sipping.

Frequently Asked Questions

Can I use bourbon instead of scotch?

Yes, though technically this becomes a different cocktail. Bourbon creates a sweeter, fuller-bodied drink that's delicious in its own right, sometimes called a "Kentucky Penicillin." However, you'll lose the classic scotch character that defines the original.

How long does honey-ginger syrup last?

Properly stored in a sealed container in the refrigerator, honey-ginger syrup lasts about 2 weeks. The honey acts as a natural preservative, but the fresh ginger will eventually lose potency. Make it in small batches for best results.

What if I don't like smoky scotch?

If you're not a fan of heavily peated scotch, you can reduce the float to 0.125 oz or skip it entirely. However, the smoky element is fundamental to what makes a Penicillin a Penicillin. Consider trying a milder Islay like Caol Ila before abandoning the float completely.

Can I make a big batch for parties?

Yes, but save the Islay float for individual servings. Combine the blended scotch, lemon juice, and honey-ginger syrup in a pitcher with ice, then pour into individual glasses and float the Islay scotch on each drink. This preserves the layered effect.

What glassware should I use?

Traditionally, the Penicillin is served in a rocks glass (also called an old fashioned glass) over ice. A double rocks glass works if you prefer more ice and a slower dilution rate.

Do I really need to make the syrup from scratch?

For the authentic Penicillin experience, yes. Pre-made honey syrup won't have the essential ginger spice, and bottled ginger syrup typically contains preservatives and artificial flavors that compromise the drink's balance. The homemade version takes just 20 minutes and makes a significant difference.

Conclusion

The Penicillin cocktail represents everything we love about modern mixology: it respects traditional ingredients and techniques while fearlessly innovating. Sam Ross's 2005 creation has rightfully earned its place in the cocktail canon, offering a perfect balance of sweet, sour, spicy, and smoky that appeals to both newcomers and seasoned whisky drinkers.

Whether you're nursing a cold, celebrating a special occasion, or simply exploring the world of craft cocktails, the Penicillin delivers a restorative experience that lives up to its medicinal name. Make a batch of honey-ginger syrup, grab your favorite scotches, and discover why this modern classic has captured the hearts of bartenders and cocktail enthusiasts worldwide.

Your prescription is ready. Enjoy responsibly.