Penicillin
The Penicillin is the only modern classic cocktail that has earned a permanent place on serious cocktail menus worldwide. Created in 2005 by Sam Ross at Milk & Honey in New York, it combines blended Scotch with honey-ginger syrup and lemon juice — then finishes with a 'float' of heavily peated Islay whisky on top. The result is smoky, citrus-bright, spicy, honeyed and entirely its own thing.
The Penicillin was invented by Sam Ross in late 2005 at the influential New York bar Milk & Honey. Ross was experimenting with combining a Whisky Sour structure with the ginger character of a Gold Rush (another contemporary cocktail he had recently created). The Islay whisky float was the inspired finishing touch — it allows the smoky character to be experienced on the nose with every sip without dominating the drink. The Penicillin spread internationally within five years and is now considered a benchmark for modern cocktail innovation.
Ingredients
- Blended Scotch whisky50ml
The body of the drink — use a decent blend (Famous Grouse, Monkey Shoulder, Compass Box Asyla)
- Fresh lemon juice20ml
Freshly squeezed only
- Honey-ginger syrup20ml
See recipe below for the honey-ginger syrup
- Heavily peated Islay whisky7.5ml
Laphroaig 10, Ardbeg 10, or Lagavulin 16 — for the float
Candied ginger on a pick (optional but traditional)
Method
- 1
First make the honey-ginger syrup: combine 100ml honey with 100ml hot water, add 50g fresh ginger root (sliced thin), simmer gently for 5 minutes, cool and strain. Keeps refrigerated for 2 weeks.
- 2
Add the blended Scotch, lemon juice and honey-ginger syrup to a shaker with ice
- 3
Shake hard for 12-15 seconds until properly cold
- 4
Strain over a large ice cube in a rocks glass
- 5
Carefully float the peated Islay whisky on top — pour slowly over the back of a bar spoon held just above the surface so the whisky sits as a layer on top
- 6
Garnish with candied ginger if using
Which whisky / spirit to use
The standard, widely-available Penicillin. The Famous Grouse is more than good enough for the body; the Laphroaig provides serious peat character on the float.
The slightly upscale Penicillin. Monkey Shoulder's three-Speyside profile is rounder than a budget blend; Ardbeg's float is sweeter and smokier than Laphroaig's.
The luxury Penicillin. Lagavulin 16 is overkill for a float — but if you have a bottle, it's the most expressive choice. Worth doing once.
Variations
Penicillin without the float
Skip the peated whisky float and substitute a small dash (5ml) of Laphroaig into the body of the drink before shaking. Less dramatic visually but easier to make at home if you don't have a steady float technique.
Smoked Penicillin
Use a peated Highland Scotch (Talisker 10, Highland Park 12) as the body and skip the float entirely. A simpler, single-whisky version with built-in smoke.
Honey-only Penicillin
Skip the ginger and use plain honey syrup (equal parts honey and water). Closer to a Bee's Knees for Scotch — less complex but easier and still very good.
Food pairings
- Oysters (the peat and the brine pair perfectly)
- Smoked salmon
- Aged hard cheeses — extra-mature cheddar, Stichelton
- Dark chocolate with sea salt
- Roast lamb
- Using a peated whisky for the body. Defeats the purpose — the float is what gives the Penicillin its layered structure. Use a non-peated blend for the body.
- Skipping the ginger and using just plain honey syrup. Without the ginger heat the drink loses its central character. The ginger is non-negotiable.
- Failing to float properly. If the peated whisky integrates into the body before drinking, the drink loses its layered aroma. Pour slowly over the back of a spoon, very close to the surface.
- Using bottled ginger juice. Make the syrup with fresh ginger root — bottled ginger juice is harsher and less aromatic.
The Penicillin is the rare modern classic that genuinely earned its status. It is more complex than a Whisky Sour, more refreshing than a Rusty Nail, and uses Scotch in a more interesting way than most cocktails manage. The honey-ginger syrup takes 15 minutes to make and lasts for two weeks — once you have a bottle of it in the fridge, the cocktail itself is a 5-minute operation.
The Penicillin converts more whisky-sceptics than any other cocktail. People who 'don't like Scotch' will drink one of these and ask for the recipe. The smoky float is the convincer — it puts the peated whisky character on the nose with every sip, but it's diluted by the body of the drink so the smoke is intriguing rather than overwhelming.
Frequently asked questions
+Why is it called a Penicillin?
Sam Ross named it after the antibiotic — the joke being that the cocktail's combination of whisky, honey, lemon and ginger is the same as a traditional Scottish hot toddy taken as a cold remedy. The 'medicinal' framing is part of the drink's identity.
+Can I make a Penicillin without the peated float?
Yes — see the 'Penicillin without the float' variation. Substitute a small dash of peated whisky into the body before shaking. The drink is good without the float, but it loses the layered aroma that defines the original.
+What blended Scotch is best for a Penicillin?
Famous Grouse (£20) is the classic budget option. Monkey Shoulder (£28) is the upscale everyday choice. Compass Box Asyla or Great King Street (£35) is the premium option. Avoid heavily peated Scotch as the body — save the peat for the float.
+How long does the honey-ginger syrup keep?
Refrigerated in a sealed glass bottle, the syrup keeps for 2-3 weeks. Make 200ml at a time — that gives you enough for 10 Penicillins. Use it in hot toddies and other cocktails too — it's a versatile bar ingredient.
+What's the difference between a Penicillin and a Hot Toddy?
Both use Scotch, honey, lemon, and ginger. The Penicillin is cold, shaken, served on ice, and finished with a peated float. The Hot Toddy is hot, built in the glass, served warm, without a float. Same ingredients, completely different drinking experiences.
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