Because it makes the cocktail so much better! Adding eggs to shaken drinks is a tradition that dates back more than a century. Besides novelty, the egg white gives your cocktail a rich, creamy texture and a beautiful foamy cap.
Unpasteurized egg whites are basically odorless and tasteless, so their contribution is almost entirely textural. Just as in a mousse or meringue, drinks that call for an egg white also include citrus juice and some sort of sugar syrup along with the liquor and egg. Agitating this mixture creates luxurious foam. While this element solidifies in mousse or meringue, the foam remains somewhat liquefied in cocktails because of the additional ingredient—the liquor.
Egg whites are mostly water and proteins. When whipped or shaken, these tightly wound proteins start to unravel and stretch out. At the same time, tiny air bubbles are folded into and trapped in the egg white. As the foam begins to form, the proteins link up in new alignments that reinforce the bubbles’ walls.
Each of the other ingredients plays a role in building a smooth, creamy mouth feel. Acid from the citrus juice strengthens bonds between the protein strands while the sugar elevates the viscosity of the water in the egg white. Bartenders face two challenges that their pastry-chef counterparts don’t have to worry about: Preventing the spread of salmonella and avoiding excessive dilution.
Drinking raw eggs is delicious, but can it be dangerous? According to the CDC, salmonella can enter an egg either through pores in the shell or during development by an infected hen. Luckily, the bacteria count in most eggs laid by previously infected hens falls well short of the threshold for causing illness.
Preventing clean eggs from becoming salmonella incubators is surprisingly easy. First, buy the freshest eggs available. If possible, purchase directly from a farmer—these eggs can be up to a few weeks fresher than their supermarket equivalents. The newer the egg, the less time bacteria have had to reproduce.
Further, buying clean, unbroken eggs minimizes the risk that foreign contaminants have been introduced into your dozen. Refrigerating your eggs will keep bacteria from reproducing, and washing your hands before preparation will further prevent germs from ending up in your glass.
To ensure that drinks are mixed thoroughly without being watery, many bartenders employ a technique called the dry shake. In this stage, all the ingredients are combined in a cocktail shaker and shaken without ice. This step allows the egg proteins to begin to unravel and form foam without being diluted by melting ice.
Ice is then added to the shaker to more violently agitate the mixture. This second phase cools the liquid and strengthens the foam. When strained, these drinks will have a velvety texture and beautiful frothy cap almost like a latte. In fact, your bartender may even use a few drops of bitters to decorate the egg foam.
Hit the Lab
Now that you know the science of using egg whites in a cocktail, it’s time to do some experimenting at your home bar by making an Americano Fizz. Originally, this drink was a play on a classic highball called the Milano e Turino. However, it became so popular with American tourists that it was lovingly renamed the Americano. Somewhere along the line, a creative bartender converted this simple recipe into a fizz by adding an egg white and the tiniest splashes of citrus and simple syrup.
1 egg white
1 tsp simple syrup
1 tsp lemon juice
1.25 oz Campari
1.25 oz sweet red vermouth
Add all ingredients to a cocktail shaker. Shake vigorously without ice for 7 to 10 seconds, then add ice and shake until cooled through, about 12 to 15 seconds. Strain into a Collins glass over ice and carefully top with a splash of soda water. To avoid spillage, add soda water slowly; the carbonation will add a lot of volume to the egg foam. Enjoy!