Whiskey sour

The whiskey sour is one of the oldest documented cocktails, with its roots in the 19th-century practice of mixing spirits with citrus and sugar to improve flavor and preserve ingredients. The term "sour" appeared in print as early as 1856 in Jerry Thomas's How to Mix Drinks, which included a recipe for a whiskey sour. The drink gained popularity in the United States, especially after the Civil War, and became a staple of the American bar. The addition of egg white, which gives the drink a silky texture and frothy head, is a variation that became common in the early 20th century, though it is not always included. The whiskey sour was also a favorite of President Ulysses S. Grant, who reportedly enjoyed it during his presidency.

The classic whiskey sour is prepared by shaking whiskey, lemon juice, and simple syrup with ice, then straining into a rocks glass over fresh ice. If egg white is used, a "dry shake" (shaking without ice) first emulsifies the egg, followed by a shake with ice to chill. The drink is often garnished with a lemon slice and a maraschino cherry. Variations include the Boston sour, which adds a muddled egg white; the New York sour, which floats a small amount of red wine on top; and the Wisconsin sour, which uses brandy instead of whiskey. Some modern recipes incorporate other citrus fruits, such as lime or grapefruit, or use honey as a sweetener. The IBA official recipe specifies 45 ml whiskey, 25 ml lemon juice, and 20 ml simple syrup, with optional egg white.

The whiskey sour has appeared in numerous films, literature, and popular culture, often as a symbol of sophistication or a character's preferred drink. It is a common offering in bars worldwide and has been featured in cocktail competitions and mixology books. The drink's balance of sweet and sour has made it a template for countless other cocktails, such as the daiquiri and the margarita. In the 21st century, the whiskey sour has seen a revival as part of the craft cocktail movement, with bartenders emphasizing fresh ingredients and house-made syrups. The drink is also a popular choice for home mixologists due to its simplicity and versatility.¹

One lesser-known fact is that the whiskey sour was a favorite of the 19th-century American writer Mark Twain, who mentioned it in his letters. Another is that the drink's name may have influenced the term "sourpuss," though this is speculative. In some historical recipes, the sour was made with a "sour mix" of lemon and lime juice, but modern purists insist on fresh lemon juice. The egg white variation is sometimes called a "whiskey sour with a foam cap," and it requires a careful shake to achieve the right texture. Additionally, the whiskey sour is one of the few cocktails that has a dedicated day: National Whiskey Sour Day is celebrated on August 25th in the United States. The drink has also been adapted into a frozen version, popular in some regions.²

Sour

A family of cocktails that combine a base spirit with citrus juice and a sweetener.

Dry shake

Shaking cocktail ingredients without ice, often used to emulsify egg white.

Simple syrup

A solution of sugar and water, used as a sweetener in cocktails.

IBA

International Bartenders Association, which publishes official cocktail recipes.