The Penicillin cocktail pairs Scotch whisky with lemon, honey and ginger, then finishes with a small smoky whisky float. That last pour supplies an aromatic opening; underneath sits a bright whisky sour with fresh ginger heat. You can make it without preparing a separate ginger syrup.
This recipe follows the fresh-ginger approach published by the International Bartenders Association. We specify a 1:1 honey syrup for home preparation because the IBA entry does not define its concentration. Keep the smoky whisky separate until the drink is in the glass.
Penicillin Cocktail Recipe
Makes: 1 cocktail. Prep and total time: about 10 minutes, including a small batch of honey syrup. Glass: rocks or Old Fashioned glass. No cooking required. Measurements use a rounded bar conversion of 1 US fl oz to 30 ml; follow one unit system throughout.
Ingredients
- 2 oz (60 ml) blended Scotch whisky
- 3/4 oz (22.5 ml) fresh lemon juice
- 3/4 oz (22.5 ml) honey syrup, made with equal volumes honey and water
- 2–3 thin, quarter-sized slices fresh ginger, about 2 mm thick
- 1/4 oz (7.5 ml) smoky Islay single malt Scotch, such as Lagavulin 16
- Ice, for shaking and serving
- 1 piece candied ginger, for garnish
Instructions
- Make the honey syrup. Stir 1 oz (30 ml) honey with 1 oz (30 ml) warm water until smooth. Let it cool, then measure the quantity required for the cocktail. There will be syrup left over.
- Muddle the ginger. Put the ginger slices in a shaker and press them with a muddler to break them up. Add the blended Scotch, lemon juice and measured honey syrup.
- Shake. Fill the shaker with ice and shake firmly for 10–15 seconds, until cold. Put fresh ice in a chilled rocks glass.
- Fine-strain. Pour through the shaker strainer and a fine mesh sieve into the glass to catch ginger fibers.
- Float and garnish. Slowly pour the smoky Scotch over the back of a spoon held just above the drink. Add the candied ginger garnish. Serve without stirring the float into the base.
What Does a Penicillin Taste Like?
Expect lemon and honey to frame the whisky, with ginger adding a peppery finish. The result should feel tart and warming rather than syrupy. Smoke is most noticeable at the rim of the glass; it becomes less distinct as the drink moves and the layers mingle.
There is no egg white in this version. It should have a lightly cloudy golden appearance, rather than the thick foam associated with some sours. For another whisky sour with a finishing float, try the New York Sour, which uses wine instead of smoky Scotch.
Choosing the Two Whiskies
Use a blended Scotch you already enjoy for the base. A relatively gentle bottle leaves room for the citrus and ginger. The float does a different job: choose an explicitly smoky or peated Islay single malt. Islay identifies an island, so check the bottle's description rather than assuming every whisky from there tastes equally smoky.
The IBA names Lagavulin 16 for the float. Another smoky Islay whisky is a substitution, and its strength and peat character may change the first sip. Keep the initial pour at the measured quarter-ounce; pouring by eye can turn a restrained accent into the drink's dominant flavor.
A heavily peated base makes a smokier variation. If you prefer whisky without citrus, the Old Fashioned recipe offers a different way to explore a bottle's flavor.
Honey Syrup and Fresh Ginger
Diluting honey before shaking makes it easier to measure and distribute. Equal volumes are the convention used here: measure the honey and water separately before combining them. Do not read the recipe as equal weights.
Use warm water and stir rather than boiling. Choose a mild honey when you want ginger and whisky to lead; a strongly flavored honey will leave more of its own character. Cover any remaining syrup and refrigerate it.
Select firm ginger, scrub or peel it, and cut thin slices. Roots vary in heat despite consistent slice sizes. Start with two slices if you are sensitive to ginger. Fine-straining matters: a regular shaker strainer can let small pieces through.
Ginger beer is not a replacement here. It introduces carbonation and a different balance of sweetness and ginger. For a fizzy ginger drink, make a Moscow Mule instead.
Why Other Recipes Use Honey-Ginger Syrup
Many versions combine the honey and ginger in a prepared syrup. Saveur's account of the Penicillin credits Sam Ross with creating it at Milk & Honey in New York in 2005, and distinguishes its simplified combined syrup from his earlier separate honey syrup and sweetened ginger juice.
Those approaches belong to the same drink family, but they extract ginger differently. This article uses muddled fresh ginger for convenience and follows the IBA ingredient structure. It does not claim to reproduce the creator's original preparation. If you use a combined honey-ginger syrup, omit the muddled ginger and begin with the same syrup volume, then adjust for that syrup's concentration and heat.
Fixing Common Problems
Too smoky: Measure the float carefully. For the next serving, try half the float quantity or choose a gentler smoky whisky. Keep the main Scotch base unchanged so you can judge one adjustment at a time.
Too sweet or too tart: Check the syrup ratio first. A 2:1 honey syrup is more concentrated than this recipe's equal-volume version. With the correct syrup, adjust by a teaspoon, or 5 ml, of lemon juice or honey syrup and taste again before increasing further.
Stringy texture: Use a fine mesh sieve when pouring. Press the ginger enough to release flavor, but there is no benefit in grinding it into an extremely fine paste.
Harsh or warm: Fill the shaker with ice and shake until cold. Chilling and the water introduced by shaking are part of the recipe, so do not simply stir the ingredients together in the serving glass.
Frequently Asked Questions
Can I make a Penicillin without the smoky float?
Yes, but it becomes a honey-ginger Scotch sour with less smoky aroma. Keep the rest of the recipe unchanged and describe it as a variation.
Can I use bourbon instead of Scotch?
You can substitute bourbon in the base for a variation. It changes the whisky character; the Scotch recipe above is the reference version. Our bourbon cocktails guide has more ideas for that bottle.
Can I prepare two cocktails together?
Double the ingredients, muddle the ginger, and shake the base together only if your shaker has enough room for plenty of ice. Divide between two glasses, then measure each smoky float separately. Otherwise, work one serving at a time.
