The Penicillin cocktail explained
The Penicillin is one of the few modern cocktails to become a genuine classic. It uses blended Scotch as the base and a peated malt as perfume. Here is why it works and how to make one at home.
A modern classic built on Scotch
The Penicillin was created by the bartender Sam Ross at the Milk & Honey bar in New York in the mid 2000s. Within a few years it was on menus around the world. For a drink that young, that is rare. Most cocktails people call classic are a century old.
It is a sour at heart: spirit, citrus and sweetener, shaken. What makes it different is the honey and ginger in place of sugar syrup and a small float of smoky whisky on top. Our guide to the whisky sour covers the family it belongs to.
Two Scotches doing two jobs
A common spec is 60 ml of blended Scotch, 22.5 ml of fresh lemon juice and 22.5 ml of honey ginger syrup, shaken hard with ice and strained over one large cube. Then 7.5 ml of a peated Islay single malt is floated on top.
The blend is the body. It is smooth, mildly malty and does not fight the lemon. The Islay malt is the perfume. Islay, an island off the west coast of Scotland, is known for heavily peated malts, the kind that smell of smoke, iodine and tar. Our guide to peat and smoke in whisky explains where those aromas come from. Shaking that malt into the drink would bury it. Floating it keeps it on top, right under your nose.
The honey ginger syrup is the heart of it
Make the syrup first. Mix equal parts honey and hot water until smooth. Grate fresh ginger, squeeze the pulp through a cloth to get the juice, then stir it into the honey syrup. Start with about one part ginger juice to four parts syrup, taste and add more if you want more heat.
Indian ginger, adrak from any vegetable market, is often fiercely pungent, so taste as you go. Keep the syrup in a clean bottle in the fridge and use it within a week or so. Ginger loses its bite as it sits. A fresh batch is the single biggest upgrade you can make to this drink.
The float works on the nose
Pour the peated malt slowly over the back of a bar spoon so it settles on the surface. Do not stir. As you lift the glass, smoke reaches your nose before any liquid touches your lips. Then the palate gets lemon, honey and the warmth of ginger.
That split is a good lesson in how we taste. Aroma sniffed from the glass and flavour rising from the back of the mouth are both smell, but they arrive at different moments. The Penicillin is designed around the gap between them. Learning to notice that gap is the core skill of any tasting, whether the glass holds whisky or beer.
Choosing the whiskies
For the base, any smooth blended Scotch works. You do not need anything expensive; the lemon and ginger will cover subtle details. A light, unpeated blend gives the cleanest contrast with the float.
For the float, you want something unmistakably smoky. A peated Islay malt is traditional. If you cannot find one, any heavily peated whisky will do the job. Use a small bottle or a miniature, since you only need 7.5 ml per drink. Some Indian distilleries now make peated single malts. They are worth trying here too.
The name is a joke, not a claim
The name plays on the honey, lemon and ginger that people associate with comfort when they feel unwell. It is a joke. The drink is not medicine and has no health benefit. Do not reach for one when you are ill or taking medication.
It is also stronger than it tastes. With 67.5 ml of whisky in the glass, it carries more spirit than a large peg. Sip it slowly, drink water alongside and leave the car at home.
Shake it hard, serve it cold
Shake the base for 10 to 15 seconds with plenty of large ice. Honey is thicker than sugar syrup and needs a firm shake to blend fully with the lemon. Strain over a single big cube in a chilled rocks glass, then add the float.
A slice of candied ginger on a pick is the usual garnish. It looks good and gives you a sweet, spicy bite between sips.
Swap one thing and taste the difference
Make the drink twice. The first time, follow the spec exactly. The second time, shake the peated malt into the drink instead of floating it. Taste them side by side and note where the smoke appears in each one: first on the nose, or spread thinly across the palate.
That single change shows you why bartenders build drinks in layers. Write down what you notice. It is the start of a palate that can explain why a drink works, not just whether you like it.
Common questions
What is in a Penicillin cocktail?
Blended Scotch, fresh lemon juice and honey ginger syrup, shaken and served over ice, with a small float of peated Islay single malt on top.
Why is the peated whisky floated on top?
So its smoke reaches your nose first. Shaken into the drink, the smoky malt would be diluted and lost behind the lemon and ginger.
Can I make a Penicillin without Islay whisky?
Yes. Any heavily peated whisky works for the float. Without one, you have a pleasant honey ginger sour, just without the smoke.
