ICE cubed

In cocktail making, ice is very important. I have begun experimenting with different types of shaped ice to minimize cocktails becoming diluted and watered down. The filler ice most commonly used at most bars is good for mixed drinks like vodka tonic, but dillutes drinks at a quicker rate that may be served on the rocks.  The thicker and denser the ice, the slower it melts. Also, as a general concept of physics, as things become colder time slows.

For practical purposes I generally like to use one inch cubes. At the restaurant, we use one inch square molds that we fill with filtered water and freeze. The molds are made of silicon and may be procured at a specialty cooking store like Sur la Table. The molds run about $12-15 and are well worth the investment.

One recent phenomena that has evolved out of Japan is the perfect ice sphere. It is literally a sphere of ice that is perfectly round and melts at a very slow rate. It is perfect for vodka on the rocks or anything that you want really cold. To make these, one could take an ice sculpting class, purchase a special mold, or purchase an ice sphere machine that is about $4000. These sphere ice methods are neat, but not practical. I have been experimenting with freezing water balloons and have achieved a similar shape. It is not perfectly round, but offers an economical alternative in a slightly tear-drop form.

Some Science Behind The Ice

While attending the world’s largest engineering school I often heard the term thermodynamics. Thermodynamics is essentially the study of heat transfer. In the restaurant business, one often hears the term in relation to refrigeration, cooling systems, and food science. The following two concepts in thermodynamics help to explain how ice melts in a rocks glass at a bar.

Enthalpy, simply put, is a way to measure the transfer of (heat) energy. It usually is measured in joules, calories, or BTUs. Assuming all things are equal within the bar’s isolated system, (ambient air temperature, atmospheric pressure, altitude) the temperature of the liquor poured over the ice within the rocks glass will fall and the crystal structure of the ice cube will become disordered and begin to melt with its temperature rising. The liquor is now suitably chilled for consumption.

The second law of thermodynamics states the theory of entropy. Ice melting in a glass within an isolated system moves to create greater disorder. Theoretically, everything is spontaneously interconnected creating an infinite amount of disorder. The variables in a bar’s isolated system might consist of a rocks glass, ice, alcohol, the thermal heat from one’s hand that lifts the glass from the bar to one’s mouth, and the ambient temperature of the room. With all these variables and disorder, the ice will melt and the liquor will be chilled to create and entropic equilibrium. Entropy also helps to explain why the longer the bartender shakes, the colder the drink. By shaking longer, the bartender is creating more disorder, resulting in a colder cocktail.