What is Egg?

Egg white in a sour is a textural ingredient. Ovalbumin and related proteins unfold when shaken, then form a foam that traps air and gives the drink a silky body and a white cap. The yolk is generally omitted in contemporary whiskey sours; whole-egg drinks (flips, some nogs) are a different family.

Use a fresh egg, or pasteurized egg white from a carton if you want to reduce Salmonella risk. People who omit egg still have a sour; they do not have the foam. Canned cocktail foam is a different product and usually a worse one.

Almost none if the egg is fresh; a sulfur note if it is not. The point is silk and a stable foam cap, not flavor. Aquafaba (chickpea cooking liquid) supplies plant proteins that can approximate the foam.

Sours with egg are 19th-century: the whiskey sour appears with egg white in many early specifications, and the pisco sour (pisco, lime, syrup, egg white, bitters) made the foam structurally expected. Mid-20th-century caution about raw egg, and later vegan preference, made the white optional in many bars.

That caution is food safety and preference. Pasteurized whites and aquafaba are documented workarounds.

Shake without ice first (a dry shake) to denature proteins and build foam, then shake with ice to chill and dilute; strain. Reverse dry-shake (ice first, then without) is an alternative some bartenders prefer for finer foam.

Use one fresh egg white or about ¾ oz pasteurized white per drink. If you do not want egg, omit it; do not replace it with aerosol cream or canned foam.