Chill a coupe or martini glass by filling it with ice water while you build the cocktail (or place in freezer for a few minutes). If using egg white, separate and measure 0.5 oz (about half an egg white) into a small container.

Dry shake

Into a cocktail shaker (without ice) add vodka 2 oz, fresh lime juice 0.75 oz, hibiscus syrup 0.75 oz, elderflower liqueur 0.5 oz, cranberry juice 0.5 oz, orange bitters 2 dashes, and the egg white 0.5 oz if using. Secure the lid and shake vigorously for 15–20 seconds to emulsify and create foam.

Wet shake

Add a generous handful of ice (about 1 cup) to the shaker. Shake again vigorously for 10–15 seconds until well chilled (the shaker should feel very cold to the touch).

Strain and serve

Dump the ice water from the chilled glass. Double-strain the cocktail into the chilled coupe using a Hawthorne strainer and a fine mesh strainer to remove ice shards and any coagulated egg white pieces. Aim for a silky pink-rose colored cocktail with a light foam on top if egg white was used.

Garnish

Float a single edible hibiscus petal or a small mint sprig on the foam, and rest a lime wheel on the rim or float it at the edge of the drink. Serve immediately.