A century-old gin sour with raspberry and egg white foam — elegance in a coupe.
The dry shake (shaking without ice first) is essential for any egg white cocktail. When you shake without ice, the egg white proteins undergo shear stress from the violent agitation, unfolding and trapping air to create foam. If you add ice immediately, the cold temperature stiffens the proteins too fast and the foam is smaller and coarser.
Always do the dry shake first, add ice, then wet shake. Some bartenders do it in reverse (wet then dry, called a 'reverse dry shake') — this produces a slightly different foam texture that some prefer. Either works — just do two shakes total, one with ice and one without.
Replace raspberry syrup with blueberry syrup. Deep purple colour, slightly less tart, more berry complexity.
Replace ¼ oz simple syrup with rose water and use rose hip syrup instead of raspberry. Floral and delicate — a spring drink.
Add 4 fresh basil leaves to the dry shake. The herb adds an anise-like savouriness to the sweet-tart raspberry that's surprisingly compelling.
Add 2 oz soda water to the glass before straining the cocktail in. Pour slowly to preserve the foam. Lighter and more approachable.