Boston Sour

Pro tips

• Dry shake the egg white mixture for 10-15 seconds before adding ice to build a thick, stable foam layer.
• Use fresh-squeezed lemon juice rather than bottled for brighter acidity and better balance with the sweetness.
• Chill your coupe or cocktail glass with ice water before straining to keep the drink cold longer and preserve the foam.
• Fine-strain through cheesecloth or a bar strainer to catch any egg white particulates and ensure a silky texture.

Substitutions

• Blended whiskey → bourbon or rye whiskey (alters flavor profile to spicier notes)
• Powdered sugar → simple syrup, 3/4 tsp (easier to incorporate, same sweetness)
• Egg white → aquafaba, 1 tbsp (vegan alternative; creates similar foam)

Storage & make-ahead

Serve immediately after preparation. Do not store or refrigerate the prepared cocktail as foam degrades.

Equipment

cocktail shaker · jigger or measuring glass · bar strainer · coupe or sour glass

Can I make a Boston Sour without egg white?

Yes, omit the egg white for a lighter version, but you'll lose the signature silky foam. Add 1/2 oz simple syrup instead to balance acidity.

What type of whiskey works best?

Blended whiskey as specified provides approachable flavor; bourbon or rye also work well for a spicier profile.

Do I need to pasteurize the egg white?

Raw eggs carry salmonella risk. Use pasteurized eggs or liquid egg white for food safety, especially for vulnerable guests.

How do I get a proper foam on top?

Dry shake (without ice) first for 10-15 seconds to build foam, then add ice and shake again before straining.

Can I make this ahead?

Prepare the whiskey-lemon-sugar base in advance, but shake with fresh egg white immediately before serving for best foam.