Shaking a Cocktail: Foam, Ice and Time

What shaking does

Dave Arnold insists that shaking is not a martial art. Banging ice around in a tin is the most turbulent and efficient manual way to chill and dilute a drink, so efficient that a shaken cocktail quickly approaches thermal equilibrium, after which very little more chilling or dilution happens whether the ice is large or small and whether you keep shaking or not. Shaken drinks end up colder and more diluted than the stirred Manhattans in the ice articles. Shaking also adds texture in the form of tiny air bubbles, and without them you do not have a proper shaken drink. The bubbles do not last, so a shaken drink is at its best the moment it is strained and fades from then on, which is a strong argument for serving small shaken drinks.

Ingredients that hold a foam

Booze alone will not foam. The most common texturizers are lemon and lime juice, which contain plant cell-wall pieces and pectin. Clarified lime juice gives a flat, dead-tasting drink compared with ordinary strained juice, because clarification removes the foam-promoting parts. The juice needs to be unclarified, not pulpy: strained juice works as well as unstrained and looks better. A simple test is to squeeze some juice into a glass and pour seltzer on top; if it foams persistently, it is a good candidate for shaken drinks. Some juices, such as cabbage and cucumber, foam even when clarified.

Milk and cream make good texturizers, especially in drinks without acid like the brandy Alexander. Whey, which is clarified milk, is a favourite of Arnold because it has strong foaming proteins but neither looks nor tastes milky, and it works with acids. Honey syrup has proteins that foam in acidic drinks. The classic choice is egg white.

Egg white, step by step

• Egg white does not make a cocktail taste eggy. It does not kill bacteria either, and a salmonella-contaminated egg can take days or weeks to die in a drink; if food safety is a concern, use in-shell pasteurised eggs, and warn guests before you serve raw egg. In Arnold’s tastings fresh eggs won, in-shell pasteurised eggs came a close second, and pasteurised whites from a carton were far behind.
• Some egg whites develop an unpleasant smell, which he compares to wet dog, ten or fifteen minutes after cracking, and it fades after a few hours. Either crack eggs just before use and serve the drink at once, or crack them hours ahead and keep them uncovered in the fridge. Some eggs never develop it. Many busy bars crack whites ahead into squeeze bottles.
• Mix every other ingredient first and add the egg white last. High acid or alcohol curdles egg white, and the upper limit for the alcohol of the mixture before adding egg is 26 percent by volume.
• Dry shake for about ten seconds without ice to break up and prefoam the white. Arnold ran side-by-side tests, and the step is needed. A warm drink does not pull the tins together like a cold one, so hold them closed.
• Add ice, shake again, and strain through a tea strainer to catch curdled white and the chalaza, even though some foam is lost.

Egg white also softens the flavour of oaky, tannic drinks, which is why it works in a whiskey sour. His test uses two sours: 2 ounces of bourbon or rye at 50 percent, a fat half ounce of strained lemon juice, three-quarters of an ounce of simple syrup and a pinch of salt; the eggless one gets a short three-quarters of an ounce of water to match the dilution, the other one egg white. The egg drink tastes less oaky and less harsh.

The ice you shake with

For ice from three-quarter-inch hotel cubes to 1.25-inch Kold-Draft cubes, the dilution is the same provided you throw the surface water off the ice first: mix in the small tin, put the ice in the large tin, cap it with a strainer and flick the tin sharply downward, then tip the ice into the small tin and shake. Crushed ice gives a very cold, much too diluted drink. A single two-inch cube dilutes much less than the same weight in small cubes but, to Arnold’s surprise, produced more foam in his tests with graduated cylinders. His solution is one big cube with two small ones for the extra dilution. Without large cubes, it does not matter what ice you use.

How to shake

The technique hardly matters technically. Shaking for between 8 and 12 seconds gives about the same drink whatever you do; a manic shake he calls the crazy monkey gets no colder and no more diluted. With thermocouples in the tins, the temperature spread between eight runs was 2.7 degrees C at 8 seconds, 2.3 at 10 and 1.2 at 14, and the curve is flat after about 12 seconds. Style is another matter, and it is not to be ignored in the cocktail world.

Some practical points: measure the ingredients into the small tin and add the ice there at home, so you never overfill the set; put the large tin over it at a slight angle and tap to seal. Shake with the small tin pointing toward you in case the seal fails. To open, push the small tin toward the gap while striking the large tin with the palm of your hand. The tins stay stuck together because the melting ice, the chilled air and the chilled liquid all contract and form a partial vacuum.

Straining

Shaking leaves tiny ice crystals, which are pebble-like with large clear ice and ragged with shattered ice. If they reach the glass they melt and change the dilution. A hawthorn strainer’s gate decides how many get through: Arnold uses it fully closed, which still lets some through, and people who dislike crystals pour through a tea strainer too. A fine-spring hawthorn is a middle way.

Two daiquiris

The Classic Daiquiri is 2 ounces of light, clean rum, three-quarters of an ounce of simple syrup, three-quarters of an ounce of strained lime juice and two drops of saline solution or a pinch of salt, a low-alcohol, high-sugar drink that finishes at about 15 percent alcohol, 8.9 g/100 ml of sugar and 0.85 percent acid. The Hemingway Daiquiri has the same rum, three-quarters of an ounce of lime juice, half an ounce of Luxardo Maraschino, half an ounce of grapefruit juice and the salt, finishing at about 16.5 percent alcohol, 4.2 g/100 ml sugar and 0.98 percent acid. Fix these two in your mind and every shaken sour falls between them. Shaken 10 seconds, the classic picks up about 55 ml of water and the Hemingway about 60, so both are diluted by a similar percentage: higher alcohol raises the percentage and so does higher sugar, and here the two effects roughly cancel out.

Arnold prefers the classic, with a slightly short measure of syrup. Shaking for only 5 or 6 seconds leaves the classic almost undrinkably sweet; shaking for 20 seconds dilutes only slightly more than 10, because the last seconds are in the flat part of the curve, and the Hemingway then tastes a little thin. The lesson is that sugar fades in flavour faster than acid as a drink is diluted, so heavy dilution calls for more sugar or less acid.