by Jim LaMar
A Sensory User's Manual
Wine tasting can be an occasional pleasant diversion or a time-and-resource-consuming passion. It can be conducted casually or formally. No matter what level of orientation or dedication is involved, some basic background knowledge and a logical approach can greatly increase individual enjoyment. Most American wine drinkers cheat themselves by not knowing how to taste; many talk the talk but fail to walk the walk, so a lot of ordinary-tasting wines gets sold at extraordinary prices.
Wine tasting is actually a complex proposition involving much more than simply sipping some fermented grape juice. There are many variable factors that affect an individual's perception of flavor in wine. There are chemical, physical, mechanical, physiological, and psychological variables.
The type and quality of the wine itself is only one aspect of tasting. Others are the size and shape of the wine glass... the individual's impartial physiological ability to smell and taste, as well as his individual flavor preferences... the temperature of not only the beverage itself, but also the ambient temperature and humidity of the tasting site... how hungry, tired, and attentive the taster is can also affect relative judgment, as well as any preconceived notions and other psychological factors.
The Four Elements of Flavor
To understand these variables, let's first look at the phenomenon of taste from a physiological standpoint. Flavor, although it may have slightly differing meanings, depending upon who is using the term, always refers to food. A food chemist may use "flavor" only to refer to aroma, while a chef is likely to include taste, texture, temperature, appearance, and arrangement in his context.
The International Organization for Standardization (ISO) defines flavor as:
FLAVOR: "Complex combination of the olfactory, gustatory and trigeminal sensations perceived during tasting. The flavour may be influenced by tactile, thermal, painful and/or kinaesthesic effects."
While the senses of smell and taste are truly most important, flavor is not an experience limited to these, but a combination of experiences from the senses of smell, taste, touch, and, less obviously, sight.
ELEMENT ONE - SMELL: Acute, Ancient and Fragile
The nose can sometimes even beat the eyes in the race for setting up the tasting expectations. An aroma can carry from one room to another, beyond the line of sight.
Of the five senses, smell is the most acute, approximately 1,000 times more sensitive than the sense of taste. As a result, what is termed flavor is influenced by roughly 75% smell (olfaction) and 25% taste (gustation) in healthy individuals. Ever notice how foods seem to taste bland or less distinctive when the nose is blocked by a cold?
Smell and taste are the chemical senses because their receptors are stimulated by chemical molecules, rather than by energy from light, pressure, or sound. As little as one molecule in a million may be detected by the nose, but it takes a minimum of one part per thousand to stimulate the tongue. As sensitive and accurate as this organ is, relatively few people ever realize its potential for sensory enjoyment by learning how it works and the language of smells.
Professional food and wine tasters and perfumers use analogies to common experience to describe aromas. Experts are those that practice and use their sense of smell most frequently.
For a substance to be smelled, it must have a certain degree of volatility (be readily evaporating) and it molecules must be hydrophobic (able to dissolve in oil, but not water). Odor molecules are typically larger than those that stimulate taste.
The odor vapor must contact receptors which cover the organs of smell, a pair of olfactory membranes. Located deep in each uppermost nasal cavity, they are brownish-yellow, roughly the size of a postage stamp, about two centimeters thick and covered in a thin layer of mucous, which the molecules must penetrate.
There are 200 distinct kinds of nasal receptors. They function using 50 million olfactory neurons, each with cilia that extend into and through the mucous. On the cilia are the receptors that capture the scent molecules, signaling the neurons to send the scent message to the brain for interpretation.
The sense of smell is ancient and primal, one of the earliest senses evolved, for locating food, warning of danger, and regulating sexual behavior. Unique among the senses, the scent message passes directly through the limbic system, the emotional center of the brain, on its way to conscious identification in the cortex. Reaction to certain smells may be instinctive; identification of those smells requires a certain amount of experience and training.
Fatigue and Adaptation
While smell is the most easily stimulated of the human senses, it is also the most fragile. Most of us have experienced detecting the aroma of cooking, maybe even from outside the house. In pursuit, we trace it to the kitchen where it becomes stronger. After standing there for a few minutes, however, the cooking odors may no longer be noticeable. This fatigue of the sense of smell is part of sensory adaptation: the self-adjustment to a constant level of stimulus in an environment, so that the individual retains sensitivity to changes. This adaptation also occurs for the sense of sight in a darkened theater or hearing in a noisy city.
..."fatigue of the sense of smell is part of sensory adaptation: the self-adjustment to a constant level of stimulus in an environment, so that the individual retains sensitivity to changes."
Some adaptation is short-term; recovery and return to the degree of sensitivity prior to exposure may only take a few minutes. Research has also demonstrated that constant environmental odor exposure can cause adaptation that lasts for days or weeks, even after removal of the odor source.
There is a great variation between individuals in the elements to which they are sensitive. A person's absolute threshold is the smallest amount of stimulus required to produce a sensation. Once that threshold is reached, unless trained, the individual can only recognize and unconsciously catalog the smell as either "familiar" or "new". Scientists have proven that the nose can detect and distinguish between thousands of different smells, depending upon individual aptitude and training.
Even individuals lacking the ability to smell specific odors (1anosmia) can often be induced to learn them by repeated exposure. Very little research has been conducted to either explain or rectify serious sensory problems of smell or taste, which can arise from congenital defect, illness, or injury, and may effect one of every 150 human beings2.
To date, scientists have cataloged over 17,000 different smells. About 10,000 can be distinguished by humans, although no one knows just how this ability works. In the early 1900s, a researcher named Henning suggested there are really only six categories of smells, combinations of which account for all the detectable odors and aromas.
Henning arrayed these categories into a three-dimensional prismatic map whereon, his theory suggests, all smells could be plotted to some point on one of the surfaces. For example, it should be possible for something to smell fruity, putrid, resinous, and burned, but impossible to have a smell that is putrid, spicy, and resinous. The combinations are interesting to plot and contemplate.
The chemical make-up of wine includes many trace elements that contribute to the combination of smells. Some of these same elements are also found, frequently in higher concentrations, in other familiar foods, spices, flowers, etc. Consequently, wine smells may often bring to mind these other familiar things, albeit with more subtlety and much less obvious or instant recognizability. With training, concentration, and practice, nearly anyone can learn to dissect and describe these elements of complexity.
ELEMENT TWO - TASTE: Categorization and Individual Sensitivity
While there may be a vast array of aroma categories, generally only four tastes have historically been considered: bitter, salty, sour, and sweet. There really is no precise definition of "basic taste"; these four only differentiate and describe common taste sensations.
Bitter tastes come from alkaloids, such as contained in coffee and quinine (tonic water). Salty tastes, by far the most common in prepared foods, come from sodium chloride (table salt), sodium nitrite (especially in smoked meats or fish), sodium bicarbonate (especially in baked goods, canned foods), and sodium benzoate (especially in soft drinks and packaged beverages, jellies and preserves, margarine and fast-food burgers).
Sour tastes come from acids (citric in oranges, grapefruit, etc., malic in apples, pears, lactic in dairy products). Sweet comes from sugars, primarily sucrose in the American diet, although there are many others (fructose, glucose, lactose, etc.).
Tastes are sensed by nerve receptors called buds and there are about 9,000 of them on the average tongue. Combinations of tastes, along with the accompanying combined aromas, account for different flavors. Taste compounds have smaller molecules than those of odors and, unlike odors, must be hydrophyllic, water-soluble.
Sensitivity to specific tastes varies considerably with individuals. It is possible in fact to be taste-blind. The test uses a chemical called phenylthiocarbamide, which tastes extremely bitter to some persons and quite bland to others. Some research has suggested that there is higher alcoholism incidence among the genetically taste-blind.
Eastern Influence- The Concept of "Umami"
Additional theories of taste perception come into Western consciousness from Eastern thought. Asians generally add "hot" (the capiscum or capsaicin taste of peppers) to the four basic tastes. At the beginning of the 1900s, Japanese scientist Kikunae Ikeda identified this element as more complex and variable than merely hot. He isolated one element that causes this taste in meat, milk, mushrooms, and seaweed broth as the amino acid glutamate and called the sensation "umami."
Rather than a specific flavor, umami is best described as a distinctive quality or completeness of flavor. The nearest English equivalent would be "savory" or "delicious." Oriental food often gets umami, its "complete" flavor, by the addition of monosodium glutamate (MSG).
The scientific journal Nature published an article in the Spring of 2002, that American scientists Charles Zuker and Nick Ryber have identified a taste receptor for amino acids, supporting the idea of Umami. Wine typically contains from one to four grams of amino acids per liter. While still controversial, there are ongoing studies of umami and it is an emerging consideration in food and wine circles.
More About Umami: Kalin Cellars' umami page has further thoughts and links concerning this element of taste.
The Taste "Map' of the Tongue is Bogus....
Taste has historically been one of the least understood sensory mechanisms. Misinterpretations of research conducted in the late 1800s, led to "tongue maps" that suggested that the basic tastes are sensed primarily by specific areas, such as the tip or center. Subsequent investigation proved that taste buds on the entire surface of the tongue can sense all of the various tastes.
ELEMENT THREE- FEELING: Texture, Body, Tannin, Alcohol and Temperature
The sense of touch figures in the overall flavor impression by conveying temperature, texture and pressure, the feeling differences that exist between cold iced tea and hot coffee, between plain fruit punch and carbonated soda, between filtered and unfiltered apple juice, between smooth pudding and crunchy cookies, or between the burn of jalapeño or the cool of menthol. These sensations of touch, irritation, or thermal differences are called chemesthesis and may be experienced in the eyes, mouth, nose, or throat. Much of the touch information of flavor is conveyed to the brain through the trigeminal nerve.
The body of a wine is felt as light or heavy, thin or full, rich or crisp. Body is one of the most often misunderstood components of wine. The description "full bodied" is frequently applied to wines that are high in either alcohol or tannin or in both, without the actual texture and weight of the wine being "full" at all. Body should be thought of as the relative "thickness" or viscosity of the wine.
One of the most prominent elements of wine "flavor" is tannin, more a sensation of touch rather than taste. It is also a significant flavor component of tea, chocolate, soy, pecans, walnuts, and the skins and seeds of many fruits, other than grapes, such as blueberries, dates, kiwi, peaches, persimmons, pomegranates, raspberries and figs. Tannin leaves a puckery, astringent feeling on the tongue, gums, and cheeks and can sometimes also taste bitter.
Wine tannins come primarily from grape skins and oak barrels and vary in strength and character. In the mouth, tannins can feel fine, round, and smooth or gritty, coarse, and angular. Tannins are one of the few flavor elements in wine that cannot be smelled.
Alcohol also is mainly experienced as an irritation of the touch sense. When the proportion is too high for the other flavor elements, alcohol may give a "burning" sensation in the nose as well as a "hot" feeling in the back of the throat or the roof of the mouth.
Wine served cold gives a taste impression that is less sweet and more acid and astringent than the same wine at a warmer temperature. This is one reason to serve fruity wines chilled, while dry, astringent ones are best near or just below "room" temperature.
The phenomenons of fatigue and adaption discussed earlier regarding smell are also considerations with taste. Astringency and bitterness require up to ninety seconds recovery in order not to influence the flavor of the next wine. This can be a very long time between tastes. A good swallow of water or bite of bread helps. Sugar also takes a while to fade from the tongue.
Chocolate, which combines astringency, bitterness and sweetness, has an extremely long aftertaste, can foul the palate for wine evaluation, and is not recommended within three hours prior to serious tasting. Cheese also clouds the ability to judge wine; as wise old French wine merchants say, "Achetez avec l'eau, vendez avec le fromage" (Buy with water, sell with cheese.)
Individual Preference and Cultural Bias
Another influence on taste besides individual physiology and ability is individual psychology and preference. Culture and upbringing provide sensory experiences that certainly influence adult taste preferences.
Americans raised in the last half of the 20th Century typically drank milk, or increasingly soft drinks, sweet and sometimes carbonated, as mealtime beverages. The longtime adage of wine marketers has been that "Americans talk dry but drink sweet". Each culture has a similar taste bias. Coca-Cola employs 200 global research and development staff, two dozen of them specialists in flavor development to pinpoint local taste preferences and adjust their product formula to local conformity. They have found that Germans like spicy, Mexicans like citric and Italians want a little bitterness. These cultural flavor preferences may also dictate wine choices to some degree.
Body should be thought of as the relative "thickness" or viscosity of the wine.
Tannin: more a sensation of touch rather than taste. Tannin leaves a puckery, astringent feeling on the tongue, gums, and cheeks and can sometimes also taste bitter.
ELEMENT FOUR - SEEING: Clues Only; Don't be Fooled
This idea of sight affecting flavor is not hard to grasp if one thinks of some food which looks unappetizing, but then tastes very good. The reverse is also true. How often is an item selected from a cafeteria line that appears very tasty but turns out to be bland or worse? This expectation based on appearance often psychologically sets up our taste buds. In wine, this sight prejudice leads us to expect that transparent and bright wines will be good-tasting, and wines that are cloudy or dull in color will not. Although this does not necessarily hold, still our sense of sight sets us up psychologically for gustatory enjoyment or disappointment.
Color can be an indicator of what the nose and the mouth might expect. Clues as to the grape varietal identity and the age of wine can be revealed by its hue and transparency or opacity. White varietal wines may appear from very pale greenish and brightly clear (suspect youth and bone dryness) to deep golden brownish and approaching translucence (probably well-aged, possibly nectar-like). Red varietals run from brickish red and nearly transparent (may be older, mellow) to deep opaque bluish-purple (expect young, brash, tannic). Bright pink rosé or blush wines are often youthful, while orangey-bricky ones are usually past their point of prime drinkability.
Although they may appear to be in a range of either red-purples or green-yellows, wine grapes are referred to as black (noir ) or white (blanc ), depending on the color of their skins at ripeness. Pinot Noir, Grenache and Mourvedre tend towards a garnet or brickish tone. Syrah, Cabernet Sauvignon, Cabernet Franc and Barbera can make wines so inky-purple they could refill fountain pens. The hues of the black grapes are consistent but they become nearly transparent when made into rosé or blush-style wines. Sauvignon Blanc and Chenin Blanc tend to be green. Semillon and Viognier are generally more yellow. Gewurztraminer and Pinot Gris (Grigio ) can have a light tannish-grey cast if allowed to fully ripen before made into wine. Most unnamed varietals fall in between these color ranges.
Sight may set up initial expectations in the other senses, or serve as confirmation after smelling, tasting, and feeling a wine's properties. When aromas of tomatoes, bouquet of earth, light tannins, a texture of velvet, and flavor of dried cherries all lead to suspicions of Pinot Noir, the garnet edge may confirm it.
METHODOLOGY: Putting it all together
Evaluating the physiological factors and chemical properties helps devise methodology to get the most from tasting wine. The taster can control serving parameters to intensify the experience and consider and maintain an awareness of elements which are beyond control but nonetheless affect the tasting occasion.
First, to make sure enough vapor is present to get a strong sense of the wine's smell, use a glass shape that can concentrate the molecules, filled only one-third full or less to allow space for the vapors to be contained.
Tilting the glass over an opaque white surface and observing the liquid's edge is the best way to judge hue and clarity. Next, swirl the wine to toss some of those molecules into the air and to increase the size of the liquid surface area from which the molecules can escape.
Then take a big, deep sniff of the wine to reach the deep-seated nasal receptors and cross the threshold of sensitivity. That first impression of a wine is really important. Close the eyes and concentrate to form an initial judgment before fatigue and adaptation set in.
Taste- Put enough wine, one-half to a full ounce, in the mouth and slosh it around to make sure as large an area of the tongue as possible has a chance to judge the wine's elements. Feel the viscosity and tannins. Allow the wine to settle in the lower jaw, letting it warm slightly while pursing the lips to breathe in a small amount of air.
Continue sucking in air, making a slurping sound as the wine and air mix. This volatilizes the wine and sends it to the back of the nasal cavity, intensifying the smell and flavor experience. After swallowing, notice which flavors and feelings are left and how well they linger.
Tasting Several Wines at One Sitting
Tasting several wines on the same occasion can somewhat alter the tasting procedure. Different contexts call for different techniques. When faced, for example, in a "blind" tasting, there are a couple of possible approaches. Whichever is comfortable and works best for the taster is proper.
Wise old French wine merchants say, "Achetez avec l'eau, vendez avec le fromage" (Buy with water, sell with cheese.)
One method is to sample and evaluate each wine completely and separately, before moving to the next one. For some people, this gives them a complete and memorable picture of the individual wine. A large "cocktail party" tasting event, where one glass, carried from table to table, is used to sample many wines, dictates this manner of tasting.
A different technique may be used at "sit-down" wine tastings with "flights" of two or more wines. In this situation, it's possible to smell and evaluate all of the wines, before tasting any of them. Proceed through once, smelling each in order, then return to those that left the weakest impression for a second chance to coax more from them.
Classify the wines, based on aromas, from "weak" to "strong" to "defective" to set the order of tasting. It requires discipline to delay tasting the strongest or most appealing wine, but it provides a chance to form a more definite impression of the lightest-smelling wines, without being overwhelmed by the "bigger" wines. Wines that have suspected defects, such as hydrogen sulfide (rotten egg), or TCA (corkiness), are postponed until last, to avoid "polluting" the senses.
White varietal wines may appear from very pale greenish and brightly clear (suspect youth and bone dryness) to deep golden brownish and approaching translucence (probably well-aged, possibly nectar-like).
Red varietals run from brickish red and nearly transparent (may be older, mellow) to deep opaque bluish-purple (expect young, brash, tannic).
TERMINOLOGY for Communication and Memory
Describing specific smells and flavors of wine is not important to the average consumer; most decide that a wine simply tastes good or not. Critics and judges, however, need to learn and apply standards of terminology. Consumers can enhance their tasting experience by learning these terms in order to communicate better with their fellow tasters, their wine merchant, and, perhaps most importantly, to develop a memory of their likes and dislikes.
Many of the smells and flavors in wine are described in terms of other fruits. Gas chromatography enables separation and identification of elements in a compound, according to the constituent's volatility. This technique has enabled chemists to establish that there are, in fact, several odoriferous molecules that are shared by wine and apples, pears, currants, raspberries, oranges, or bananas. These include acetic and butyric acids, the alcohols propanol, terpinol and hexanol, the carbonyls ethanal, acetone and diacetyl, and the esters isoamyle acetate, ethyl caproate, and ethyl butyrate. Different combinations and amounts of these and other compounds give fruits their distinct aromas and flavors and provide great variety in wine.
Until her retirement in 2003, from the University of California at Davis, Dr. Ann Noble led wine research on smells and flavors. She began to develop her theories on aromas specifically recognizable in wine in the 1980s and her colleagues continue this research today. Dr. Noble headed a project to develop an inexpensive and easy tool to aid in learning wine flavor terminology.
The Aroma Wheel is a kind of pie-chart that lists, categorizes and groups hundreds of smells and odors that may be present specifically in wines. Each of these specific aromas is grouped into one of nine major general categories: floral, fruity, vegetative, nutty, woody, caramelized, earthy, spicy, or chemical.
Dr. Noble's Aroma Wheel website explains how to get one and use it train your "nose and brain to connect and quickly link terms with odors...using materials available from the grocery store."
A wine palate is part ability and part experience. The individual's preferences for and sensitivity to smell and taste elements, along with the memory of their taste history, combine to form the palate. In developing this personal wine palate, remember to consider the temperature, the texture, and the feel, as well as the flavors. Besides judging the wine, learn to recognize which flavor elements help you arrive at that judgment and use accepted terms to describe them. Use the swirl, sniff, and slurp method to enhance your tasting ability. When you find yourself absent-mindedly swirling, sniffing, and slurping your milk glass, coffee cup, or soda can, you have reached the first level of expertise and commitment to appreciating fine wine.
Jim LaMar is editor of Professional Friends of Wine, instructs Introductory Sensory Evaluation of Wine at California State University, Fresno, and has been drinking, thinking, teaching and writing about wine for 30 years. He is a member of Professional Friends of Wine.