Chill a coupe or Nick & Nora glass in the freezer or by filling it with ice water while you build the drink. In a cocktail shaker, add gin, St-Germain, fresh lemon juice, crème de violette, simple syrup, and the egg white if using.

Dry shake

Without ice, seal the shaker and shake vigorously for 15–20 seconds. This dry shake emulsifies the egg white and produces a velvety foam. If not using egg white, give a 5–10 second gentle shake to combine ingredients.

Wet shake

Add ice to the shaker (about 1 cup) and shake vigorously for 12–15 seconds, until the exterior of the shaker is very cold and slightly frosted.

Strain

Discard ice or water from the chilled glass. Double-strain the cocktail into the chilled coupe or Nick & Nora glass using a Hawthorne strainer and a fine mesh strainer to ensure a silky texture and to remove any tiny ice shards or egg white solids.

Garnish & Finish

Carefully express a lemon twist over the surface of the cocktail to release oils, then run the twist around the rim and drop it into the drink or suspend it on the rim.

Float the edible violet gently on the foam. If desired, add 1 dash of Angostura or a floral bitter on top of the foam for an aromatic highlight and a tiny pattern.

Serve immediately while the foam is fresh and aromatic.