The Whiskey Sour is one of those cocktails that people come back to over and over. Whiskey, lemon, sugar. The balance between those three things is what makes it work, and when it’s right, you understand why this recipe has survived since the Civil War era.

The dry shake matters

If you’re using egg white (or aquafaba as a vegan substitute), the dry shake is the step that separates a good sour from a great one. Shake everything without ice first for about 30 seconds to aerate the protein. Then add ice and shake again to chill. This two-step process creates a thick, stable foam that sits on top of the drink and gives every sip a creamy texture.

Skip the egg white if you prefer, and you still get a clean, balanced sour. But the foam adds a dimension that’s hard to replicate any other way.

Finding the balance

The ratio here is two parts spirit to three-quarters part lemon to half part sweetener. If your lemon is very tart, bump the syrup slightly. The drink should hit tart first, with the sweetness catching up a beat later. That tension is what keeps you sipping.

Drop three or four dots of bitters on top of the foam. They add an aromatic spice note and look good against the white surface. Use a toothpick to drag them into a pattern if you want the bartender touch.

The spirit choice

Seedlip Spice 94 brings allspice and cardamom that stand in for bourbon’s warmth. For something closer to a traditional bourbon profile, try Lyre’s American Malt, which has more caramel and oak. Either works. The Whiskey Smash takes this same base and adds mint for a summer variation.