The Penicillin is proof that a genuinely new classic can still emerge from a modern bar. Created in New York in the mid-2000s, it takes whisky, honey and ginger and finishes with a float of smoky peated Scotch, so the first sip is warm and sweet and the last note is all smoke. It manages to feel both comforting and a little bit serious, which is a rare balance to strike.
This is one of my go-to cold-weather drinks, and the float is where all the character lives. Here is how I build one, and why the honey-ginger syrup deserves its own ten minutes of attention.
What Is a Penicillin?
A Penicillin is a modern whisky cocktail made from blended Scotch, fresh lemon juice and honey-ginger syrup, shaken and served over ice with a float of peated Scotch on top. It was created by bartender Sam Ross in New York in 2005, drawing on the old Whisky Sour template but adding ginger and honey for warmth and a smoky float for depth. It has become one of the most widely imitated modern cocktails of the last twenty years.
The blended Scotch gives a smooth, approachable base, the honey-ginger syrup brings sweetness and a gentle heat, and the lemon keeps everything bright. The final float of peated whisky sits on top rather than mixing in, so the smoke hits you on the nose and the first sip, then fades as you drink.
Ingredients
This makes one Penicillin. Use the card to scale it up, and make the honey-ginger syrup ahead if you are serving a few.
A Few Notes on the Ingredients
Blended Scotch is the right base for the shaken part of this drink, since it is smoother and more approachable than a single malt, letting the honey and ginger come through cleanly. Save your more expensive single malts for sipping neat rather than shaking into a cocktail.
The peated Scotch float is where the whole drink earns its personality. It sits on top rather than mixing in, so you get a wave of smoke on the nose before you even taste the drink. A little goes a long way here, so do not be tempted to over-pour it.
Honey-ginger syrup is worth making properly rather than adding honey and ginger separately. Simmer grated fresh ginger with equal parts honey and water for about ten minutes, then strain. It keeps in the fridge for a couple of weeks and makes the whole process much easier when you are making more than one drink.
Fresh lemon juice, as always in a sour-style drink, is what keeps the sweetness from taking over. Do not skip it or reach for the bottled version.
Variations Worth Trying
- Mezcal Penicillin: swap the base Scotch for mezcal and use a very light float for a smokier, more agave-forward twist.
- Spiced Penicillin: add a pinch of chilli to the honey-ginger syrup for extra heat.
- Rye Penicillin: use rye whiskey as the base for a spicier, drier character.
- Sparkling Penicillin: top with a splash of soda for a longer, lighter version.
Skip the Mixing
The Penicillin is a genuinely satisfying cocktail to make at home, and the smoky float never gets old, but it does call for two different Scotches and a batch of syrup, which is more of a project than a quick round usually allows. When you want something equally bold with nothing to simmer or float, our Pornstar Martini brings its own big personality, and the wider Boozy range is right here too.
Penicillin FAQs
What is in a Penicillin cocktail?
Blended Scotch, fresh lemon juice and honey-ginger syrup, shaken and served over ice with a float of peated Scotch on top for a smoky finish.
Is a Penicillin cocktail smoky?
Yes, primarily from the peated Scotch float. The base whisky itself is smooth and approachable, so the smoke comes through as a top note rather than dominating the whole drink.
Who invented the Penicillin cocktail?
It was created by bartender Sam Ross in New York in the mid-2000s, and it has since become one of the most influential modern cocktails, widely copied and adapted around the world.
Is a Penicillin cocktail sweet?
It should be balanced rather than sweet, with the honey-ginger syrup softening the whisky and lemon rather than dominating them. The smoke and citrus keep it feeling grown-up.
Can I make a Penicillin without peated Scotch?
You can, but you will lose the signature smoky finish that defines the drink. If you cannot get hold of a peated whisky, it is still a good honey-ginger Whisky Sour, just a different cocktail in character.
