• 2 oz Pisco
• .75 oz lime juice
• .75 oz simple syrup
• 1 fresh egg white
• 4 drops Bittermens Hopped Grapefruit Bitters

In a mixing tin, combine pisco, egg white, lime juice, and simple syrup, then add ice and shake vigorously.  Strain into a coup or cocktail glass, and garnish with drops of bitters atop the foam.