The Penicillin: A Smoky Scotch Cocktail You Can Make at Home
The Penicillin is a modern Scotch cocktail combining blended whisky, fresh lemon juice, honey syrup, and ginger liqueur, topped with a smoky Islay single malt float. It takes about 5 minutes to make. This recipe serves one.
- Basescotch
- Strength25% ABV, approximate
- Methodshake
- Glassrocks
- Icelarge cube
- Difficultyeasy
- Total6 min
- Serves10
- Sweet
- Tart
- Spicy
- Smoky
- Jigger or measuring spoons
- Cocktail shaker
- Strainer
- Rocks glass
- Large ice cube
- Peeler or knife
- Contains gluten (Islay single malt Scotch whisky)
The Penicillin is the drink that made people who hate Scotch change their minds. It balances the peaty punch of Islay whisky against the bright warmth of honey and ginger. Created in the mid-2000s by Sam Ross at Milk & Honey in New York, it quickly became a modern classic—a status it earned, not inherited.
The magic is in the structure. A base of blended Scotch keeps things smooth and approachable. Fresh lemon and honey syrup give it body and cut. Ginger liqueur adds a spicy kick. Then a quarter-ounce of Islay single malt floats on top, so every sip starts clean and finishes with a wisp of campfire smoke.
You don't need a bar full of gear for this penicillin recipe. The hardest part is measuring the float without dumping it all in. We'll get to that.
About the Penicillin
The Penicillin originated at Milk & Honey, a now-closed speakeasy in Manhattan, and is credited to bartender Sam Ross. It belongs to the sour family. What sets it apart is the Islay Scotch float—a technique borrowed from the Gold Rush and other honey-based drinks, but here it introduces a distinct smoky character.
The drink is typically served over a large ice cube in a rocks glass, which keeps it cold with minimal dilution. It is not an official IBA (International Bartenders Association) cocktail, but it is widely considered a benchmark of contemporary cocktail culture.
Why it works
- 1The honey syrup and ginger liqueur create a rich, spicy base that stands up to the smoky float without being overpowered.
- 2Shaking with ice chills and dilutes the drink to about 20-25%, which opens up the whisky's aromatics and softens the peat.
- 3The Islay float sits on top because it's denser with alcohol and lower in sugar, so it layers naturally rather than mixing in.
- 4Fresh lemon juice balances the sweetness and smoke, keeping the drink bright and preventing it from becoming cloying.
- 5Blended Scotch provides a neutral, smooth canvas that lets the honey and ginger shine, unlike a single malt that would dominate.
Ingredients
Serves 10.
2 oz Blended Scotch whisky, e.g. Famous Grouse, Monkey ShoulderSmooth and approachable, it lets the honey and ginger lead.
- 1/4 oz Islay single malt Scotch whisky, e.g. Laphroaig, Ardbeg
The smoky float that defines the drink. A little goes a long way.
3/4 oz Fresh lemon juice, strained, no pulpBottled juice lacks the brightness. Squeeze it fresh.
3/4 oz Honey syrup, 2 parts honey to 1 part water, stirred until dissolvedAdds sweetness with floral depth and body that simple syrup can't.
3/4 oz Ginger liqueur, e.g. Domaine de CantonSpicy, sweet, and the backbone of the drink's warmth.
3 slices Fresh ginger, for garnish, thinly slicedA visual cue and a whisper of extra spice on the nose.
ingredients
The blended Scotch is your canvas. Monkey Shoulder gives a vanilla-sweet base, Famous Grouse is nutty and reliable. Avoid anything too peaty here—the float handles that job. For the float, Laphroaig 10 is the classic choice, but any Islay works. Ardbeg is more medicinal; Lagavulin smoother and sweeter. For the honey syrup, a 2:1 ratio (two parts honey, one part hot water) is thicker and richer than a standard 1:1. It coats the palate better. Domaine de Canton is the standard ginger liqueur. If you can't find it, a good ginger syrup will do, but you'll lose some complexity.
You need: jigger or measuring spoons, cocktail shaker, strainer, rocks glass, large ice cube, peeler or knife.
Method
Make the honey syrup
If you don't have honey syrup ready, combine two parts honey with one part hot water and stir until fully dissolved. Let it cool to room temperature. This keeps it fluid enough to measure and shake properly.
Look for: The syrup is clear and uniform, with no honey settling at the bottom of the cup.
Common mistake: Using undiluted honey. It won't incorporate into the cold drink and will sink to the bottom, leaving you with a dangerously sweet last sip.
Into a cocktail shaker, pour 2 oz blended Scotch, 3/4 oz fresh lemon juice, 3/4 oz honey syrup, and 3/4 oz ginger liqueur. Use a jigger for accuracy—this drink is all about balance, and eyeballing it will throw the sweet-sour ratio off.
Look for: The liquid sits at the bottom of the shaker, a pale amber mixture. No separation of honey or syrup.
Common mistake: Skipping the jigger. A heavy pour of lemon makes it tart; too much honey makes it cloying. Measure it.
Fill the shaker about two-thirds full with ice. Shake hard for 12 to 15 seconds. You're not just chilling the drink—you're adding the water that mellows the smoke and binds the honey to the spirit. The shaker should become painfully cold to the touch.
Look for: The outside of the tin frosts over. When you stop, the tin feels like it's burning your hand with cold.
Common mistake: A gentle, polite shake. That leaves the drink warm and under-diluted. Go hard, and listen for the ice rattling.
Strain the mixture into a rocks glass over one large ice cube. A large cube melts slower than regular ice, so the drink stays cold without getting watered down. If you only have small cubes, that's fine—just drink it a bit faster.
Look for: The liquid is a clear, deep amber with no cloudiness. A single ice cube sits in the glass, barely submerged.
Common mistake: Using crushed or small ice that dilutes the drink too fast. The smoky float will wash out and the honey will thin to nothing.
This is the signature move. Hold a bar spoon just above the surface of the drink, with the bowl of the spoon touching the liquid. Slowly pour the 1/4 oz of Islay whisky onto the back of the spoon. It should spread across the surface and stay on top, not sink into the body of the drink.
Look for: A distinct, lighter-coloured layer of whisky sits on top of the amber mixture below. The two liquids don't merge.
Common mistake: Pouring it straight in without the spoon. It will mix and the entire drink becomes smoky, losing the contrast that makes this cocktail work.
Gently twist a thin slice of fresh ginger over the glass to release its oils, then drop it in or perch it on the rim. Do not stir the drink. The float is meant to be experienced first, then blended by each sip.
Look for: A bright, pale ginger slice rests on the glass, a single visual note against the dark amber drink.
Common mistake: Stirring the drink before serving. It mixes the float and ruins the layered sip.
Tips from the bar
- 1Chill the rocks glass in the freezer for 10 minutes before you start. It keeps the drink colder with less dilution.
- 2Make a batch of honey syrup and keep it in the fridge. It lasts a month and makes this drink a two-minute job.
- 3If you don't have ginger liqueur, muddle a few thin slices of fresh ginger in the shaker with the honey syrup before adding the other ingredients.
- 4Use a large ice cube—it melts about half as fast as standard cubes, preserving the balance of the drink.
- 5Smell the float before you sip. The peat aromatics are half the experience.
Variations
- Make it a Gold Rush: skip the ginger liqueur and float; use just bourbon, lemon, and honey syrup for a simpler, sweeter sour.
- For a lighter version, swap the blended Scotch for an unpeated blend and use an eighth of an ounce of Islay for the float instead of a quarter.
- Try a mezcal float instead of Islay for a different kind of smoke—more vegetal and earthy, less medicinal.
- For a spicier kick, add a bar spoon of fresh ginger juice to the shaker along with the other ingredients.
Substitutions
- Ginger liqueur: Use a homemade ginger syrup (1:1 sugar and water, infused with ginger) and add a dash of Angostura bitters for complexity. The drink will be less spicy and thinner-bodied.
- Islay Scotch: Any heavily peated single malt works. If you only have a blended Scotch, you can't replicate the float, so consider adding a few drops of liquid smoke to the honey syrup instead.
- Honey syrup: Maple syrup is a close substitute, though it adds a woody, sweet note that changes the character. Simple syrup will make it thinner and less rich.
Serving, storing, batching
Serve it after dinner, when the smoke and honey can stand up to a rich meal. It pairs well with dark chocolate or a sharp blue cheese. The drink itself is the digestif.
The honey syrup can be refrigerated in an airtight container for up to a month. The mixed cocktail is best made fresh—shaking and serving immediately. Don't batch it with ice; the dilution changes the balance.
To serve a crowd, combine the blended Scotch, lemon juice, honey syrup, and ginger liqueur in a pitcher without ice. Refrigerate until cold, then pour over a large ice cube in each glass. Float the Islay individually on each drink just before serving. For 10 servings, multiply all ingredients by 10, but keep the float at 1/4 oz per glass.
Questions people ask
The classic Penicillin calls for 2 oz blended Scotch, 3/4 oz fresh lemon juice, 3/4 oz honey syrup, and 3/4 oz ginger liqueur, topped with a 1/4 oz float of Islay single malt Scotch. The honey syrup is made from two parts honey and one part water.
Combine blended Scotch, lemon juice, honey syrup, and ginger liqueur in a shaker with ice. Shake hard for 15 seconds and strain into a rocks glass over a large ice cube. Float the Islay Scotch on top using the back of a spoon, then garnish with a slice of fresh ginger.
You need blended Scotch whisky, Islay single malt Scotch, fresh lemon juice, honey syrup, and ginger liqueur. Fresh ginger is used as a garnish. The exact proportions are 2 oz blended, 3/4 oz each of lemon, honey, and ginger liqueur, and a 1/4 oz float of Islay.
In metric, use 60 ml blended Scotch, 22.5 ml fresh lemon juice, 22.5 ml honey syrup, 22.5 ml ginger liqueur, and a 7.5 ml float of Islay single malt. Shake the first four ingredients with ice, strain, and float the Islay on top.
Common variations include swapping the Islay float for mezcal, replacing the ginger liqueur with fresh ginger juice, or using bourbon instead of Scotch. Some versions add a dash of bitters or use a different honey varietal like orange blossom or manuka.
The name is a playful reference to the drink's restorative ingredients—ginger and honey are both traditional home remedies. The smoky Scotch is the 'medicine' that makes it memorable. It was coined by bartender Sam Ross at Milk & Honey in New York.
It opens with a bright, sweet lemon-honey note and a warm ginger spice. The smokiness from the Islay float arrives on the finish and lingers. It's smooth and surprisingly approachable for a Scotch drink.
The Penicillin is shaken. It contains lemon juice and honey syrup, which need vigorous shaking to properly dilute and emulsify with the spirit. Stirring would leave the drink too strong and the honey wouldn't integrate properly.
You can, but it won't be a Penicillin. The smoky float is essential to the character of the drink. If you don't have Islay, you could add a very small amount of a peated whisky to the base, but you'll lose the layered contrast.
Last word
The Penicillin is inventive and comforting at once. It's a drink you make when you want something that tastes like a craft bar, but you're standing in your own kitchen. Mix one. Float the smoke. Sip slowly.
