Beyond shaken vs stirred - The science behind the perfect cocktail

Molecular gastronomy has taken the food world by storm and exemplifies the notion that science does not always occur in a lab. Understanding the physical and chemical transformations of food during cooking can guide flavor pairings and allow innovative cooking processes. While foodies around the world already follow this trend, scientists might also benefit from the techniques utilized in molecular gastronomy.

 

But why should food have all the fun? Forward-thinking mixologists have begun to incorporate the equipment and techniques of molecular gastronomy to make cocktails. While physics and chemistry are probably not the first thing that comes to mind when thinking about getting a drink, mixologists use properties of thermodynamics and physics of colloids to control the appearance, flavor and texture of a drink. Understanding these properties allows molecular mixologists to put a spin (sometimes literally!) on traditional cocktails.

 

The basic element of a mixed drink is ethanol. Ethanol contains both polar and non-polar ends. This chemical property allows ethanol to interact with a variety of non-polar aromatics allowing them to flavor ethanol. Traditionally, this flavoring occurred through distillation and soaking.

 

The flavor of distilled liquors originates from its ingredients. The application of a rotary evaporator allows the creation of new flavors. In a rotary evaporator, low pressure in a rotating container allows volatile components to vaporize while non-volatile components remain as liquid. The vapors are cooled back to a liquid state and can be incorporated in liquor. The cool thing about this technique is that it can separate desired volatile components (such as the taste of a hot pepper) from undesirable non-volatile components (such as capsaicin in a habanero).

 

This technique is applicable outside of the mixology world and might be useful in drug discovery from natural products. The high pressure reduces the temperature required for boiling and allows the extraction of compounds that under normal pressure decompose below their boiling point. This might allow for distillation of some plants that denature at low temperatures.

 

Soaking aromatic compounds in ethanol is another way to extract flavor. While this technique works well in infusing flavor, it requires time. The use of a whipped cream dispenser can quickly disperse flavor from porous substances (ex. coffee, chocolate) into vodka. Under high pressure, vodka dissolves in nitrous oxide. This high-pressure liquid displaces air bubbles in the porous substance and removal of pressure releases nitrous oxide bubbles, thereby pulling the flavor into the vodka.

 

Cocktails are not just about flavor combinations. The look and texture also contribute to the overall appeal of a cocktail. The decision to shake or to stir can greatly impact the appearance and texture of a drink. For example, shaking a Manhattan turns it unappealingly cloudy. In other cases, air introduced via shaking provides a desired viscous texture as in the Ramos gin fizz. Application of techniques and equipment borrowed from science creates new clarification procedures and textures. Centrifugation and the application of agarose gels remove particles. These techniques create clear liquids that can be applied to drinks. The addition of tapioca maltodextrin creates cocktails in a variety of textures including powdered and solid. 

 

If the notion of awesome cocktails is not enough to sway one to get behind the molecular mixology trend, the educational potential of these techniques might. For many individuals, the applicability of physics and chemistry to the real world is not apparent. Perhaps introducing individuals to these concepts using sensory-based models (like food and drinks) might solidify the relevance of these topics and foster an interest in some basic principles of chemistry and physics.

 

Molecular mixology is an intriguing avenue to express scientific knowledge. While molecular mixology incorporates principles of chemistry and physics into the creation of the perfect cocktail, consuming too many cocktails will make you forget every law of physics, chemistry and... well... everything else!