The whisky sour, or whiskey sour as it's traditionally known thanks to being made with bourbon, first appeared in Jerry Thomas' The Bartender's Guide in 1862.
The whisky or whiskey sour is made with a bourbon, or Scotch whisky, lemon juice, sugar and egg white.
These are shaken up and served with a citrus or maraschino cherry garnish.
Alternatives include a New York sour, which has red wine floated on top.
Fill cocktail shaker with ice and add all the ingredients except the garnish. Shake really hard for about 30 seconds.
Strain the mixture into a glass filled with ice and garnish with cherry and orange slice.
50ml Old Pulteney 12 Years Old
10ml apricot liqueur
15ml fresh grapefruit juice
15ml lemon juice
5ml sugar syrup
15ml egg white (optional)
Add all ingredients to a cocktail shaker.
Shake well and fine strain into a cocktail or coupe glass, then garnish with a grapefruit twist.