The Whiskey You Use Makes the Drink
Both bartenders agree that the most classic tasting Whiskey Sour is made with bourbon. Gullo says that if she uses a bourbon, she typically goes for something a little bigger and boozier like Old Forester, while O’Neill prefers the spicier, woodsy flavors of Elijah Craig. But both bartenders also agree that bourbon is not the only whiskey that you should be using in your Whiskey Sour.
O’Neill and Gullo both like making their sours with scotch (for that hint of smoke) or rye. Gullo’s own personal twist on the cocktail calls for a split base of bourbon and rye (she usually uses Rittenhouse Bonded Rye or Redemption Rye). “It makes [the cocktail] a little spicier and not as sweet,” she says.
Egg Whites Are Essential
Unless you’re a vegan or just too squeamish, adding an egg white to your Whiskey Sour is non-negotiable. “It completely changes the feel of the cocktail,” says O’Neill. Gullo agrees, arguing that a Whiskey Sour should always be made with egg whites. “You know you created the perfect Whiskey Sour when you see people scoop out their flag garnish covered in a thin foam of egg whites—like meringue—and then they lick it off of the orange like they’re licking frosting off a spatula.” Make sure to crack the egg right before adding the whites to the shaker. “If egg whites are too old they don’t froth up right,” says Gullo.
The Glass You Use Changes the Drinking Experience
Gullo and O’Neill disagree on their choice of glassware. Gullo feels that the cocktail should always be served over ice in a rocks glass (unless specifically asked otherwise by a customer), while O’Neill opts for a coupe or cocktail glass. According to O’Neill, the ice can cause the cocktail to separate faster and impart a “metallic” tang to the drink. Gullo counters by saying that if you “[let the cocktail] sit to the point where the drink becomes over diluted and breaks up the egg whites, you’re drinking it wrong.”
Shaking Technique Matters
In order to create the frothiest, creamiest Whiskey Sour, both bartenders had their own opinions on the best techniques for incorporating egg whites into the drink. O’Neill opts for a more traditional approach and dry shakes the cocktail before adding ice to the tin. “You want to really make sure that you bind the ingredients, and [your shake and the ice you use] will add air to the egg whites to fluff them up.” He uses a large format cube—or a small block of ice—to aerate the whites, and a couple small cubes of ice to add dilution to the drink.
Gullo on the other hand uses a whip shake for her Whiskey Sour. She says that she only puts “two big cubes in a shaker tin” with the cocktail and “moves it around in a circular pattern rather than straight up and down.” This gives the cocktail, and the ice, enough room to move around in the tin to aerate it, while saving time and energy that dry shaking requires. Gullo argues that if you shake it hard enough, pour the drink straight away after its shaken, and let it sit in the glass for a second after you pour it before adding ice, it creates “a beautiful perfect foam” everytime.
Don’t Forget the Bitters
To combat egg whites’ occasionally unpleasant smell and to make the cocktail more visually appealing, both Gullo and O’Neill garnish their Whiskey Sours with bitters. “When you go in to drink the cocktail it gives off these sensational aromatics that are almost like inside of a [whiskey] barrel,” says O’Neill. Gullo goes beyond simply dashing the bitters onto the foam, opting to add some pyrotechnics to her presentation. She mixes a tiny bit of overproof rum with Angostura bitters in a spritzer bottle and sprays the mix over the drink through a lit match. “You get this amazing burnt bitter on top of your Whiskey Sour,” she says. Needless to say, you should probably leave that technique to the professionals. Stick to dashing a few drops onto the top of the drink. If you want to get fancy, try swirling the bitters with a toothpick.
Always Garnish with a Flag
In addition to the garnish of bitters, both bartenders opt for a traditional flag garnish (an orange slice wrapped around a brandied cherry on a pick). No matter which whiskey they choose to use, O’Neill and Gullo agree that the citrus garnish is an absolute must. “I can’t think of a whiskey that wouldn’t love to have an orange with it—or a cherry for that matter,” says Gullo.