Penicillin
A modern classic from Milk & Honey — blended Scotch, honey-ginger syrup, and lemon, shaken and finished with a smoky Islay float.
About the Penicillin
The Penicillin is a modern classic that layers blended Scotch, fresh lemon, and a homemade honey-ginger syrup, then finishes with a float of peaty Islay single malt on top. The float is meant to be smelled as much as tasted — it hits the nose with smoke before the drink hits the palate.
It was created in 2005 by bartender Sam Ross at Milk & Honey in New York City, as a riff on another Milk & Honey original, the Gold Rush (bourbon, lemon, honey syrup). Ross swapped in blended Scotch, added the honey-ginger syrup for heat and sweetness, and topped it with a peaty float — a combination that spread quickly to craft cocktail bars around the world.
It’s now considered one of the defining modern classics of the 2000s craft cocktail revival, and one of the few contemporary drinks to earn a place alongside Prohibition-era staples on serious cocktail menus.
The Classic Recipe
Classic Penicillin — Serves 1
- 2 oz (60ml) blended Scotch whisky
- 3/4 oz (22.5ml) fresh lemon juice
- 3/4 oz (22.5ml) honey-ginger syrup (roughly equal parts honey and water, simmered with fresh ginger)
- 1/4 oz (7.5ml) peaty Islay single malt Scotch, for the float
Method
- Shake the blended Scotch, lemon juice, and honey-ginger syrup with ice.
- Double strain into a rocks glass over fresh ice.
- Float the Islay Scotch on top by pouring gently over the back of a spoon.
- Serve without stirring the float in, so each sip catches the peat smoke on the nose first.
Tips for the Best Penicillin
- Use fresh ginger juice. Real ginger juice — not powdered ginger — is what gives the syrup its characteristic heat.
- Float carefully. Pour the Islay Scotch slowly over the back of a spoon so it sits on top rather than mixing in.
- Don’t stir the float. Sip through it as-is so you get the smoky aroma with every mouthful.
- Pick your blend and float separately. A softer blended Scotch as the base, with a distinctly peaty Islay malt for the float, gives the clearest contrast.
- Double strain. It catches any ginger pulp left over from the syrup, for a cleaner pour.
Popular Variations
Lazy Penicillin
Swaps the honey-ginger syrup for fresh ginger juice mixed directly with honey — less prep, similar profile.
Final Ward
Phil Ward’s direct riff: lime juice and rye whiskey in place of lemon and Scotch.
Mezcal Penicillin
Swaps the peaty Islay float for a mezcal float, leaning even further into the smoke.
Bourbon Base
Bourbon or rye in place of blended Scotch shifts the drink back toward its Gold Rush roots.
Where to Buy
The float is where bottle choice matters most in this drink — a genuinely peaty Islay single malt makes the difference between a background note and the drink’s signature aroma.
An entry-level Islay single malt
A younger, more affordable Islay bottling still brings enough peat character for a convincing float.
Check price on AmazonLaphroaig 10 Year
The classic choice for this drink — heavily peated, smoky, and intense enough to stand out even as a quarter-ounce float.
Check price on AmazonHow to Serve
Glass: A rocks glass, with the drink strained over fresh ice rather than served up.
Ice: Fresh ice for serving, separate from the ice used to shake — keeps the drink cold without over-diluting.
Batching for a crowd: Batch the Scotch, lemon juice, and syrup together and keep cold; shake to order and add the float fresh to each glass just before serving.
Related Database Entries
Explore the key ingredients and spirits in this cocktail: