A Whiskey Sour is one of the most honest cocktails there is: spirit, citrus, sweetener. The ratio matters more than the ingredients. When the sweetener is homegrown plum syrup — made from the same trees that fill your yard every August — it stops being a variation and starts being its own thing.
The plum syrup does three jobs in this drink: it sweetens, it adds color (a deep rose-burgundy that looks like the fruit looks), and it brings a slight tartness that lifts the citrus without fighting the bourbon. The amaro is optional but worth it — it adds a herbal bitter note that keeps the drink from going sweet.
How to Make It
On the egg white: This recipe includes an optional egg white, which creates a silky texture and the foam that holds the bitters pattern on top. Raw egg carries a small food safety risk. Skip it if you prefer — the drink is excellent either way. See our disclaimer page for more information.
- Chill your glass. A coupe in the freezer for 5 minutes, or a rocks glass with ice water while you build the drink.
- If using egg white: combine bourbon, plum syrup, lemon juice, amaro, and egg white in a shaker without ice. Dry shake hard for 15 seconds to emulsify.
- Add a large scoop of ice and shake hard for another 10–12 seconds. The shaker should be very cold and starting to frost on the outside.
- If skipping the egg white: combine everything with ice in one step and shake for 12–15 seconds.
- Double-strain into your chilled glass. If serving on the rocks, pour over a large cube.
- Add 2 dashes of Angostura bitters. If you have egg white foam, dot 3 small drops and drag a toothpick through to make a pattern. If no foam, just dash directly over the drink.
Lemon matters here
Fresh-squeezed only. Bottled lemon juice has a cooked, flat quality that makes the whole drink taste off. This cocktail only has a handful of ingredients — each one carries its weight.
Which Bourbon to Use
The plum syrup has stone fruit, a little vanilla, and slight tartness. You want a bourbon that works with that, not against it.
Best overall
Buffalo Trace
Approachable, vanilla-forward, and priced for cocktails. Doesn't fight the fruit.
Richer, more oak
Knob Creek
Higher proof and more tannin. Makes the drink a bit bigger and drier.
Spicier option
Bulleit Rye
Technically a rye. The spice and the plum create an interesting back-and-forth.
Special occasion
Woodford Reserve
Complex enough to taste on its own. Lovely here if you have a bottle open.
Variations
- Smoked Plum Sour — Smoke the glass before pouring: invert a rocks glass over a lit piece of cinnamon stick or cedar chip for 20–30 seconds. Wipe dry and pour the cocktail in. The smoke lingers in the first sip.
- Plum & Thyme Sour — Add a sprig of fresh thyme to the shaker with the other ingredients. Strain it out. It adds an herbal note that makes the plum taste more like a garden and less like a juice bar.
- Sparkling Version — Build the drink without shaking: combine bourbon, plum syrup, and lemon juice over ice in a rocks glass and top with 2 oz of club soda. Stir once. Lower ABV, still great.
- Mocktail — Replace the bourbon with strong-brewed hibiscus tea (chilled) and use the same ratios. The tea has enough tartness and color to hold the drink together.
On the amaro
Amaro Nonino is the recommendation — it has an orange, herbal bitterness that works perfectly here. Averna is a good substitute: darker, more caramel. Either one keeps the drink from going one-dimensional. If you don't have amaro on hand, a bar spoon of Aperol works in a pinch.