Whiskey sour

The whiskey sour is a mixed drink containing whiskey (often bourbon), lemon juice, sugar, and optionally, a dash of egg white. With the egg white, it is sometimes called a Boston Sour. For those who do not like or cannot have egg white (e.g., due to religious concerns or allergy to eggs), pineapple juice is used as a substitute. It is shaken and served either straight up or over ice.