D I S T I L L E D S P I R I T S A N D K E Y F L AV O R S :
SMELLING ROSES, FRUIT, STINKY FEET AND MUCH MORE IN MY GLASS WRITTEN BY GARY SPEDDING, PH.D. & JOHNNY JEFFERY, M.S.
T
he understanding of the flavor of distilled spirits forms an
(CH3CH2OH) itself is a solvent and confers tactile sensations of
incredibly complex topic—one which is only now really
warmth or heat and mouthfeel (viscosity), but it also extracts and
becoming understood at the molecular level. The origins and
interacts with many other components to “enhance” the flavor
controls of the generation of over 1000 components bear upon
profile. Ethanol has a sensory perception threshold of around
the overall flavor profile of each characteristic style of the classic
1.4 grams per 100 mL of solution. It has been discovered that
spirits. This forms the basis for “the art of the distiller” and
non-volatile components extracted from oak casks during spirit
relies upon the use of their senses to control and create the
aging can influence the structure of ethanol-water complexes
desired profile.
in distilled spirits. This then affects the flavor activity of other
Though thousands of components are present in these
more volatile flavor compounds in the product. While we cannot
complex beverages, a key set of components form the base, or
delve too deeply into all these subtleties, the rest of this article
foundation, from which the overall structure of each spirit is
will illustrate the origin of mostly volatile and a few non-volatile
built. In the past and for all time the human senses have been
components which come together to give rise to the sensory
used to determine if the product is as intended and maintains
pleasures (or displeasure if something is wrong) of consuming
a suitably long shelf-life. The distiller must therefore, from a
such beverages. However, flavor pleasure is a personal thing, so
sensory perspective, understand at least several dozen flavor
the point here is to teach or train the distiller or consumer to
components and be able to control their formation, be cognizant
understand a few key flavor notes only. Compared to water and
of maturation factors, or manipulate conditions to provide the
alcohol they form collectively only a small fraction of the whole,
consumer with a quality product of consistent flavor and stability.
but contribute massively to the overall pleasurable soul of the
A brief review is presented below on just a few key players in
spirit.
the flavor profile of the most complex types of spirits—the so-
Building a vocabulary of terms is the first step in understanding
called brown spirits in particular. Gin, as a classic white spirit,
this flavor chemistry. Some flavor notes are above sensory
and unaged spirits—white whiskey, tequila and rum—must also
detection threshold concentrations, many more are below any
be understood in terms of flavor production (including flavor
detectable levels from a sensory perspective. Yet the interplay
from added botanicals, for instance) and some issues discussed
of several hundred to thousands of components is essential
below pertain to these unaged spirits, at least up to the point of
to creating the quintessential distilled spirit. No one will ever
discussion of barrel aging.
establish a simple base set of components that, when mixed at
WE BEGIN WITH WATER. Then we add alcohol. Distilled spirits
appropriate concentrations and in the correct proportions, will
contain the highest concentrations of alcohol of all alcoholic beverages, yet water (H2O) is still, for most spirits, the dominant chemical component. Water quality is important for producing spirits (and must be especially pure for dilution). Flavor issues originating or emanating from water supplies is not covered in depth here, however, some physical attributes of solutions dictate the overall flavor profile and deserve a brief mention. In typical spirits 40% alcohol by volume is the norm and thus ethanol is the next most abundant component present. Ethanol
give the desirable and acceptable flavor profile of an authentic spirit. While science makes advances in understanding flavor, it will still be both an artistic (a personal sensory experience) and a scientific endeavor to produce a consistent, desirable and quality commodity. A basic understanding of key flavor notes, however, will assist the distiller as part of a quality assurance and control program as will be seen below. A product can be technically perfect from an instrumental testing viewpoint – all components quantified to the nth degree—yet may be absolutely
WWW.ARTISANSPIRITMAG.COM 53