Penicillin
The Penicillin was created by Sam Ross at Milk & Honey in New York in 2005 and is one of the most significant original cocktails of the contemporary revival. Ross also created the Paper Plane; the Penicillin is the more complex and more demanding of the two. The structure is a whisky sour built on blended Scotch, sweetened with honey syrup and given its heat by fresh ginger shaken in alongside it, with a float of Lagavulin 16 over the surface. Honey and ginger together define the drink's character, combining floral sweetness with a sharp, spiced bite. The blended Scotch supplies the base, and the float supplies the peated smoke that the blend alone could not deliver at the volume a balanced sour requires. The float is the technique most commonly misapplied. Poured correctly it sits as a distinct aromatic layer, met at the nose and on the first sip before integrating gradually into the drink below.
Glassware: Rocks Glass
Garnish: Candied Ginger
Ingredients
60ml
The structural base. A quality blend with genuine malt character and modest smoke performs best; a thin or neutral one cannot hold the syrup and lemon in balance.
22.5ml
Two parts honey to one of warm water, and nothing steeped in it. The official build keeps the honey and the ginger separate so the ginger arrives fresh from the shake rather than softened by half an hour in hot syrup.
2 to 3 slices
Quarter-sized slices, shaken with everything else rather than pre-steeped. Fresh ginger hits brighter and hotter than a syrup made from it, and the heat is the point: it is what stops the honey settling into blandness.
22.5ml
Squeezed immediately before use. The acid backbone that stops the honey tipping the whole drink toward sweetness across the glass, and the reason the ginger reads as heat rather than sugar.
7.5ml
Floated over the surface, and named by the specification rather than left to the island. Its smoke and maritime character must be assertive enough to be met at the nose before the drink is tasted at all.
Instructions
Squeeze the lemon juice immediately before building the drink.
Add the blended Scotch, honey syrup, lemon juice and the ginger slices to a shaker with cubed ice.
Shake hard for 12 to 15 seconds, which is what draws the heat out of the ginger.
Double strain over a single large ice cube in a rocks glass, leaving the ginger behind.
Float the Lagavulin slowly over the back of a bar spoon held just above the surface.
Place candied ginger on the rim and serve immediately.
Source: the IBA (Official IBA specification; method ours). Last checked 13 August 2026.
Expert Tip
Slice the ginger thinly and let the shake do the work. Two or three quarter-sized slices go into the tin with everything else, and twelve to fifteen hard seconds against cubed ice draws the heat straight out of them. Thin slices give up more than thick ones, and the drink wants the ginger arriving as a distinct element rather than a background note. Double strain, or the fragments come with it. A fine strainer over the glass catches the ginger and the ice shards together, which matters in a drink served over one large cube where anything floating is visible for the whole glass. A drink with insufficient ginger heat tastes like a honey-lemon sour with Scotch in it, which is pleasant and is not this one. If the heat is not arriving, the ginger was cut too thick or the shake was too polite, and both are easier to fix than any adjustment to the honey.
Flavour Profile
The Origin
Sam Ross developed the Penicillin at Milk & Honey on Eldridge Street in New York in 2005, in the environment Sasha Petraske had built and which set the standards of the contemporary revival.
The name is wordplay on the antibiotic, linking warming ginger, honey, lemon and medicinal Islay smoke to the drug that changed the treatment of infection. Whether it is genuinely restorative is debatable; that it became one of the most ordered modern classics in serious bars worldwide is not. Scotch was not an obvious base in a revival built largely on gin classics and American whiskey, and this drink is what established it as one.
Honey and Ginger, Kept Apart
The official build does not use one. Honey syrup and fresh ginger go into the shaker separately, and the shake does the work a steeping would.
Two parts honey to one of warm water makes the syrup; two or three quarter-sized slices of ginger go in alongside it. Shaken hard against cubed ice for twelve to fifteen seconds, the ginger gives up its heat directly into the drink and is strained out at the end. The result is brighter and hotter than a syrup steeped for half an hour, because the volatile compounds that make fresh ginger sharp are the first thing lost to time and warmth.
A pre-made honey-ginger syrup is the common shortcut and a reasonable one for volume, and it is worth knowing that it makes a rounder, gentler drink rather than the same drink prepared earlier.
The Float Technique
The float is what separates this from a standard Scotch sour, and it is the element most commonly mishandled.
It works on the density difference between the diluted, chilled sour and the undiluted malt, poured over the back of a bar spoon held just above the surface so it sits as a distinct layer. The purpose is experiential: the peat, iodine and saline character arrive at the nose and on the first sip before the honey and ginger take over. Poured too fast or from too high it breaks through the surface, and the drink remains good while the progression that defines it is lost.
Choosing the Malt
The specification names Lagavulin 16 rather than leaving the bottle open, and the reason is arithmetic rather than reverence.
The float has to be assertive enough to register at 7.5ml, and peat varies enormously between distilleries and expressions. Naming the bottle fixes how much smoke that measure carries. Lagavulin's high phenol content and maritime, iodine-inflected peat are what make it read at that volume; lightly peated or unpeated malts barely register. Another Islay malt substitutes perfectly well and the drink stops matching the specification when it does, so it is worth saying so on a menu.
The Blend Underneath
A quality blend with genuine malt character meets the honey, the ginger and the lemon as a four-way balance. A thin, neutral blend disappears entirely and leaves a drink that tastes of syrup and lemon with a Scotch note somewhere behind.
Blend and float are a complementary pair: grain sweetness, gentle malt and modest smoke below, intense peat and maritime character above, and together they deliver a complete Scotch experience that no single expression could.
The Spirit
Lagavulin 16The Islay single malt the Penicillin names by bottle rather than by style: sixteen years old, heavily peated, and bottled at 43%. Smoke, iodine and dried fruit in a spirit whose long finish is most of what it is bought for.
Frequently Asked Questions
What is a Penicillin?
A whisky sour built on blended Scotch, sweetened with honey syrup and sharpened by fresh ginger shaken in, with a float of Lagavulin 16 over the top. Sam Ross created it at Milk & Honey in New York in 2005.
Why is it called a Penicillin?
Wordplay on the antibiotic: warming ginger, honey, lemon and medicinal Islay smoke, linked to the drug that changed the treatment of infection. Whether it is genuinely restorative is debatable; that it became a modern classic is not.
Which malt for the float?
One assertive enough to register at 7.5ml. Laphroaig 10 is the most cited, medicinal and intensely peated; Ardbeg 10 runs drier and more saline. Both work, and lightly peated or unpeated malts barely register at all.
Can I use honey syrup and ginger syrup separately?
Honey syrup and fresh ginger is the official build, so that split is correct rather than a compromise. Ginger syrup is the substitution to watch: it arrives rounder and sweeter than fresh ginger shaken in, and the heat is most of what the drink is for.
Master the Techniques
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Where this one sits
Recipe by Jerry Can Spirits
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