In a small pot, bring the water and sugar to a boil until the sugar has dissolved. Remove from the heat. Add the hibiscus flowers and let infuse for 15 minutes. Strain through a sieve set over a bowl. Let cool. Cover and refrigerate until completely chilled, about 1 hour.
In a personal blender, pulse the grapefruit juice, aloe juice, gin, hibiscus simple syrup and egg white for a few seconds. You can also mix the ingredients vigorously in a cocktail shaker.
Pour into a large glass filled with ice cubes. Garnish with a grapefruit wedge and a few dried hibiscus flowers, if desired.
You will obtain enough simple syrup to make 8 cocktails.
The egg white can be replaced with 4 to 5 drops of vegan emulsifier.
Recipes with the "Healthy Pick" stamp have been evaluated by a registered dietitian member of the Ordre professionnel des diététistes du Québec.