A sour cocktail is perhaps the most versatile framework when it comes to mixed drinks. It is both accessible and interesting, combining the flavors of any spirit with acid from fresh citrus while balancing that with some form of sugar. The sour formula is also flexible and forgiving, allowing different ingredients to successfully change the cocktail—sometimes subtly, but often with dramatic effect. For example, the Bee’s Knees cocktail would be a plain gin sour (not really a popular choice) if not for the honey syrup. By just using honey instead of simple sugar syrup, it achieves an unexpected depth of character that mingles in unpredictable ways with the gin making it a memorable favorite.

Any base spirit works as a sour. Exploring the possibilities will lead you into categories like the Daiquiri, Sidecar, Margarita and the list goes on and on as you swap sweeteners or add other ingredients. It’s how recipes are invented. Even a basic Whiskey Sour ranks among the best ways to enjoy whiskey, but like other spirits, there are so many ways to swap ingredients that entire books could be written about it. Over the next couple of weeks we will feature some examples, and today we feature a modern variation created in 2010 by Thad Volger at Beretta in San Francisco.

Beretta’s Rattlesnake by Thad Vogler, Beretta, San Francisco
2 oz rye whiskey
1 oz lemon juice
.5 ounce grade B maple syrup
2 dashes Peychaud’s bitters
.5 oz egg whites

Shake all ingredients and double strain into a chilled cocktail coupe. Garnish with broad lemon twist.

The classic Rattlesnake cocktail dates back at least to the 1930’s. We are talking Harry Craddock’s Savoy Cocktail Book days. It is normally a rye whiskey sour plus a few dashes of absinthe for a nice floral effect—a good drink it its own right. Fresh lemon juice is a fixture in whiskey sours because it pairs better than lime, and Beretta’s variation follows suit. However, here we skip the absinthe and replace it with Peychaud’s bitters for the floral effect. This Rattlesnake also emphasizes the sweet side of the drink by using Grade B maple syrup which has a darker color and deeper flavor than your typical pancake topping.

Rye whiskey is specified for its spicy quality that helps it stand up to the other ingredients. They used Wild Turkey Rye at Beretta, but you can probably get away with what you have. This drink also uses egg white. You can usually get two of these drinks out of a single egg white, but we rarely take the time to measure the whites. It can also help to dry-shake the ingredients before adding ice. This helps build up a frothy emulsion. Then, toss in your cubes and shake to chill. Make sure you have a glass tall enough to accommodate the froth that usually comes at the end of the pour. Scent this meringue with lemon oil as you give the peel a healthy twist.