Sam Ross built this syrup into the Penicillin at Milk & Honey in 2005 and changed what a modern cocktail could taste like. Honey carries the warmth, fresh ginger carries the burn — and the result is a syrup that turns lemon, whisky, and a smoky Islay float into one of the most successful drinks of the craft revival. It earns its keep far beyond the Penicillin, too: any winter drink that wants spice without dryness.
The Sam Ross Build
The Penicillin's defining move was not the recipe's structure — a Scotch sour with an Islay float is a fairly logical idea once stated. The move was this syrup, the way ginger gets folded into honey so the heat and the floral arrive together rather than in sequence. Without it, the Penicillin would be a curious whisky sour. With it, a landmark.
Two Methods
Two ways to do it: steep (the kitchen method — sliced ginger, gentle heat, time) or juice (the bar method — fresh ginger juice stirred into honey syrup). Juiced ginger is brighter, more immediate, more aggressive. Steeped ginger is mellower and easier to control. The recipe below uses the steep method; bars with a Hurom or Breville juicer often prefer the juice approach.
Sourcing the Ginger
Use fresh, firm ginger root — the kind where the skin pulls taut over the flesh, not the dried-out stuff at the back of the produce shelf. Old ginger is fibrous and weak; the syrup will reflect that. A thumb-sized piece (roughly 2–3 inches) is the right scale for one cup of syrup.
Storage
Fresh ginger introduces some perishability — refrigerated, expect about two weeks before the syrup begins to thin or lose its edge. The heat mellows over time, so use fresher batches when you want the spice to register. A small splash of vodka (a teaspoon) extends shelf life noticeably.
Bottom Line
Keep a jar in winter especially. Penicillin, hot toddies, ginger-leaning Moscow mules, whiskey sours that want a little burn — once you have it on hand, you find reasons to use it.