Boston Sour

Pro tips

• Dry shake the egg white and lemon juice first (without ice) for 10–15 seconds to build foam before adding ice and whiskey.
• Use fresh-squeezed lemon juice, not bottled, for brightness and balance against the powdered sugar.
• Chill your glass first to keep the drink cold and preserve the foam layer after straining.
• Strain through a fine mesh to catch any ice shards and ensure a silky texture.

Substitutions

• Old Mr. Boston blended whiskey → bourbon or rye whiskey (adjust to taste for bolder flavor)
• Powdered sugar → simple syrup, 1 tsp (no dry shake needed; use wet shake only)
• Egg white → aquafaba, 1 oz (vegan; shake same way as egg white)

Equipment

cocktail shaker · jigger · fine mesh strainer

Can I make a Boston Sour without egg white?

Yes, omit the egg white for a standard whiskey sour, but you'll lose the signature silky texture and foam head that define the Boston Sour.

How do I get the foam on top?

Dry shake the egg white with lemon juice and powdered sugar for 10–15 seconds without ice to aerate it, then add ice and whiskey and shake again before straining.

What can I substitute for Old Mr. Boston blended whiskey?

Any blended or bourbon whiskey works; use a 2 oz pour of similar proof for consistent flavor.

Is this cocktail sweet or sour?

It's balanced—the powdered sugar and egg white add sweetness and body, while fresh lemon juice provides bright acidity.

Can I make it ahead?

No; mix and serve immediately to preserve the foam and prevent the egg white from breaking down.