If using egg white: separate one egg and measure 1/2 egg white (about 0.5 each). Place gin, dry vermouth, elderflower liqueur, fresh lemon juice, simple syrup and egg white into a cocktail shaker.

Dry Shake

Seal the shaker and shake vigorously without ice for 10–15 seconds to emulsify the egg white and incorporate air, producing a silky foam.

Wet Shake

Add ice to the shaker (about 1 cup) and shake again hard for 12–15 seconds until well-chilled and the exterior of the shaker becomes frosty.

Strain

Double-strain the cocktail through a fine-mesh strainer into a chilled coupe or martini glass to remove ice shards and any coagulated bits for a silky texture.

Finish & Garnish

Express the oils of a lemon peel over the surface by holding the peel over the glass and giving it a quick twist, then run the peel around the rim and drop it into the drink as garnish.

Optional Aromatic Finish

If desired, add 1 dash of Angostura bitters on top of the foam and use a toothpick to create a small decorative swirl, or float an edible white flower or microherb for visual contrast.

Serve

Serve immediately while foam and chill are at their best.