SHAKE all ingredients with ice and strain back into shaker. DRY SHAKE (without ice) and fine strain into ice-filled glass.
This Whiskey Sour isn’t very sour and those wanting a drier drink should consider reducing the sweetener to nearer 15ml (1/2oz).
Adding a couple of dashes aromatic bitters greatly contributes to the cocktail’s flavour but this also adds trace amounts of sugar.
Adapted from the classic serve by yours truly (Simon Difford) in January 2019.