When a glass of wine is raised to mouth level in order to be drunk, it is almost impossible not to notice its aromas and to appreciate them, the information we unconsciously receive from the olfactory sense determine, in a relevant way, the agreeability or the unpleasantness of any food or beverage, every thing which has a nice smell, including foods, positively predispose us to its agreeability. That incredible group of sensations that we usually define as “flavors” and that allow us to tell a food from another as well as making the act of eating or drinking pleasurable, is mainly determined by the smell sensations we receive from the nose; indeed, taste is the union of fundamental gustatory sensations (sweet, salty, sour and bitter) enriched with the endless patrimony of aromas and smells. When we are in the condition of not smelling aromas, such as when our nose is congested, we are used to say we cannot taste flavors; indeed, what is really lacking is that fundamental contribution the olfactory sense adds to the sense of taste, that fundamental and discerning factor that makes us tell an apple from a peach, one beverage from another. The role played by the olfactory sense is fundamental not only for the evaluation of foods, indeed it has been, and surely still is, the sense that more than any other else allowed humans to recognize dangerous or favorable situations or substances, a fundamental condition for surviving.

 We would like to say this straight: the olfactory evaluation of a wine is the most complex of them all, it surely is one of the most amazing phases of the whole evaluation, therefore this report has the sole purpose of introducing the reader to the charming but difficult task of olfactory evaluation of wine. We will continue talking about olfactory evaluation of wine, as well as the direct influence and connection with taste, in future issues: a such vast argument like this which is so fundamental for the evaluation of wine cannot be underestimated or ignored, it surely deserves the highest consideration and importance to any wine taster.

 In order to understand the fundamental importance of the olfactory sense in tasting, we invite you to make the following experiment. Take three glasses and pour some fruit juice in every one of them, such as orange juice, pineapple juice and peach juice. Blindfold yourself and hold your nose by using your fingers or something else that could be suited for this purpose. Now take a glass at random and, without seeing its content, take a little sip without swallowing. Make sure the liquid is passed all over the mouth and try to taste the juice. Expel the juice from mouth and write down the flavor of the juice according to what you believe it was. Repeat the same operations with the remaining glasses. Did you guess the three fruit juices right? Probably no. The sensations you will have perceived in your mouth will have been of sweetness, more or less evident, sourness, more or less strong, and a more or less intense sensation of bitterness, however, these were the only clues you had to tell the flavor of the juice. Without the help of the olfactory sense it is practically impossible to determine the exact flavor and the taste of a food, therefore, it is almost impossible to recognize it.

 The main problem in evaluating the olfactory profile of a wine, as well as of any other substance which emits odors, is the scarce habit one generally has in concentrating and realizing the aromas and odors he or she is smelling; the olfactory sense, no matter it is continuously working and sending the perceived sensations to the brain, is mainly an instinctive sense that needs a rapid reaction and evaluation, sometimes we do not even realize the odors we are smelling, however the brain perceives them and, according to experience and association, determine the agreeability of the stimulus and predisposes the individual to face dangerous or pleasing situations. The conscious evaluation of smells requires attention, concentration and, alas, experience as well as memory. Attention and concentration are attitudes that everyone has, experience and memory, in this case concerned to the olfactory sense, is something that not everyone has, they are attitudes of the ones that decided, both for will and opportunity, to always pay attention to the information perceived by the nose. This condition can be, of course, achieved by anyone and everyone can surely succeed in this. However it is almost impossible to determine and recognize a smell in case it was never perceived before, it is impossible to form an olfactory memory, in our specific case concerning to wine's aromas, in case one does pay scarce or no attention to what is being perceived by nose. The solution in forming one's experience and olfactory memory is only one: practice, lots of practice and more practice. Every time a wine is being tasted, this is also true for everything that emits smells, try to pay the best attention and concentrate on every aroma you can smell while trying to associate to every smell an odor already perceived in the past, therefore recognizable, or, in case it is an unknown smell, try to associate it to that specific wine while trying to remember about it. This is easier said than done. This surely is a very hard job, however, this is the key for success in evaluating a wine. Be patient and be prepared to do all your best with the sincere will and modesty to learn something new.

 Another problem with the recognition of aromas is concerned to the difficulty of finding aromas in a group of many smells, sometimes pretty vast and complex. Smelling an apple and being able to recognize it, is certainly easy: every apple in good conditions undoubtedly has an evident and clear aroma of apple. The aroma of apple is also found in wine, however in this specific case, this will not be the only aroma that will be perceived in a wine's bouquet and this aroma must be recognized and identified among many other. Moreover, during the evaluation of wine's aromas, and however of everything else, the intensity of the smell must be evaluated as well; a condition which is objectively measurable as well as being something which is indisputably subjectively perceived. An aroma can be defined as “light” by a certain individual whereas can be defined as “pretty intense” by others, moreover, for some this aroma could not be perceived at all no matter it is objectively present in the bouquet. The subjectivity of this judgment is also determined by what is usually defined as “threshold of perception”, that is the minimum level of stimulation in order for an individual to detect any specific sensation.

 Concerning this aspect, we would like to invite you to do the following experiment in order to determine your personal “level of threshold of perception”. Take five glasses and fill them with about 100 ml of plain water (about 3.38 fl.oz.) at a temperature of 20° C. (68° F) Also take some ethyl alcohol and, by using a dropper, add 8 drops of alcohol to the first glass, 6 to the second, 4 to the third and 2 to the fourth. The fifth glass will contain just plain water. Take five lids and cover all five glasses and wait for about one hour. Randomly change the order of glasses and uncover the first one: smell and try to evaluate the intensity of the perceived aroma. Repeat the same with all the remaining glasses. At the end of the experiment, try to tell the quantity of alcohol contained in each glass, from the glass containing plain water to the one containing 8 drops of alcohol. The best thing is to have someone preparing the glasses in order to be as much objective and honest as possible. Repeat the same experiment by using vinegar instead of alcohol. Did you guess the order of glasses right? Perhaps, for some glasses you will have been undecided about their contents, in others you did not smell any odor: this is pretty normal just because every person has its own minimum threshold of perception as well as having its own tolerance to specific stimuli. In case you guessed the order of glasses right, congratulations, you are going to become an excellent taster: your nose will surely be by your side in a determinant way and it will help you in finding the most hidden and subtle secrets of a wine.

 Like we said already, the olfactory evaluation of a wine is undoubtedly the most complex phase of the whole analysis, both for the number of aromas that can be perceived and for the objective difficulty of the recognition of aromas and lastly, for being able to recognize aromas among many other. The role of olfactory memory is determinant and important, remembering a specific aroma and, mostly, being able to recognize it, become a strategic requirement for any taster, a requirement that can be refined and developed with practice and commitment. What can be seen as a very difficult and complex task, can also be seen as a “fun game” where anyone can be an “aroma investigator” which discovers every time new and amazing clues that will allow him or her to enrich his or her personal “mosaic” of aromas.

 Aromas in a wine are determined by specific volatile smell substances and their perception is what makes the process of evaluation and recognition of aromas to begin. All these substances are found, for example, in fruits and flowers and thanks to the common association we usually do with their aromas, this allows us to recognize, as well as allowing others to recognize them, the aroma of an apple or a rose. This characteristic is extremely useful in the recognition of aromas because allows us to determine odors as a consequence of an analogy, that is, every time an aroma of banana is being perceived, we will say, according to this analogy, we are smelling an aroma of banana instead of the volatile chemical substance which originates it. This method greatly simplify the recognition process as well as the communication process and it will be easier for others to understand what we perceived: it is easier, as well as being more immediate and practical, to say a wine has an aroma of banana instead of isoamyl acetate, that is the volatile substance which originates this aroma. In order to better understand the vastness of volatile substances found in wine, the number of substance found so far are a little more than 120. It should be clear that olfactory evaluation of a wine is vast as well as complex, the number of smells and aromas, in case we are also going to include defective and unpleasing aromas, is certainly high.

 Recognizing aromas in a wine can be extremely difficult, in particular for those wines that, after some years of aging, have developed complex aromas and smells that can be hardly associated, or however recognizable, with foods of other things which are commonly known. Sometimes, when we are about to evaluate complex aromas, or aromas that are scarcely recognizable or a wine having a particularly rich bouquet, it may also happen one of the most recurring problems that may arise during the evaluation of aromas: adaptation, that is the nose has gotten used to some aromas. Our olfactory apparatus tends to get adapted to certain stimuli when they are perceived for a very long time, in other terms, after having perceived a specific smell, usually within some minutes, it will tend to lower the perception of this smell and it will end up ignoring it, it acts like a sort of filter in response to a prolonged stimulus: the olfactory apparatus will have got adapted to that smell. Of course this effect is reversible, it will be enough to interrupt this stimulus for some minutes and, like a sort of magic, the smell that was previously ignored will be perceived again. This phenomenon is easily experienced in case we enter a room having a strong smell: in the beginning this smell will be clearly and easily perceived, after some minutes the perception will be lowered and it will disappear with time, indeed, other smells that was covered by the strong one will be now perceived no matter the strong smell is still present in the room. It will be enough to exit the room for some minutes and to enter again: the strong smell will be perceived again. The very same also happens during the olfactory evaluation of a wine: after some minutes spent in recognizing specific aromas, the nose will tend to get tired and it will seem not to work properly like it used to do. This “danger” must be avoided in any way and it is advisable to subdivide the olfactory evaluation of a wine in subsequent phases while taking little breaks in order to prevent nose adaptation.

 Practice and experience will teach everyone the most efficient method for recognizing aromas and for their proper classification in memory. Do not get discouraged if at first everything will seem overwhelmingly complex and difficult; you should remember it was hard for every taster and this seems to be the price we have to pay because of the scarce attention we usually pay on our olfactory sensations. In a way, wine tasting, and in particular the olfactory evaluation, can be seen as an useful work that will help us in reeducating our senses, and this surely is a very positive aspect, something we can take as an advantage while “playing” and we all know that the best way to learn something is to do that without being forced, but with passion and, above anything else, with that pleasing satisfaction that is usually ensured by the “playing” aspect of things. With time you will realize to have developed your own and personal technique in recognizing aromas, indeed, every taster has a personal technique and every technique is surely functional as well as efficient, the most important thing is that this technique works very well for oneself.

 However there are some general hints that can help everyone in recognizing aromas, some little helps that will probably be useful during the hard and complex task of the olfactory evaluation. Aromas are generally classified in categories, such as fruit aromas, flowers aromas, vegetable aromas and so on. During the olfactory evaluation it is advantageous to concentrate to the aroma's category instead to the aroma itself. It should be noticed that in evaluating the olfactory profile of a wine we do not know in advance what kind of aromas we are going to find, that is you cannot expect every wine having an aroma of banana or strawberry, it should be remembered every wine is different from another, they can have common characteristics, including aromas, but they will surely be different anyway. According to this aspect, it is more easy and advantageous to focus on aromas categories instead of continuously asking oneself about any specific aroma. In other terms, when an aroma is perceived in a wine, it is better to ask oneself whether that aroma resembles the one of fruits instead of asking oneself whether that aroma is of apple or any other specific fruit. As soon as the aroma can be classified in a specific category, and by doing so we will automatically exclude all the others as well as hundreds of aromas, it will be more easy to recognize that particular aroma. This method can be further improved and developed on. Let's consider in this example the category of fruits aromas: we can subdivide this category in other categories such as “red berried fruits”, such as strawberry and raspberry, “white fruits”, such as apple and pear, and so on. This new method allows us to proceed in subsequent steps where we will exclude in every step a certain category, therefore groups of unwanted aromas, and this will lower the possibility of error while increasing the possibility of success in identifying a specific aroma. When a fruit aroma is being perceived, we will ask ourselves whether this aroma is of a “red fruit” or “white fruit”, and this approach will be continued and applied until the final identification of the aroma.

 A mistake that can be made during the olfactory evaluation of a wine is self suggestion. In case the taster is prejudicially convinced a specific aroma is present in a wine, he or she will end up being so convinced about it that the aroma will be perceived even when it is not obviously present in that wine. A serious mistake that can be easily avoided in case the evaluation is done by trying to recognize categories of aromas instead of trying to recognize every specific aroma. Finally, it should be remembered that temperature, like we already said in the previous issues of DiWineTaste, plays a fundamental role in the development of aromas; a wine which is too cool will develop little aromas, whereas when the wine is too warm the aromas will be evidently coarse and ordinary. This is the reason why wines whose organoleptic characteristics are being evaluated, are not served at their typical serving temperature, they are usually evaluated at temperatures from 12°C to 14°C for white wines (53° F to 58° F), and from 16° C to 20° C for red wines. (60° F to 68° F)

 The procedure that allows a proper evaluation of wine's aromas is generally divided in specific phases where each one of them allows the evaluation of specific types and categories of volatile substances. It should be remembered that the shape and volume of glass, as well as the ratio between contact surface and the volume, are all determinant factor for the proper development and perception of aromas. In our specific case we assume tasting glasses, such as the ISO tasting glass, or glasses expressly designed for this purpose are being used. Before illustrating the procedure for olfactory evaluation, it should be remembered that aromas are produced by chemical volatile substances which are molecules having different “weights”. The lighter substances are easily volatilized, whereas the heavier ones need a higher oxygenation, and others which are very heavy, need a proper and real “hyper-oxygenation” in order to volatilize.

 The way a wine is smelt plays a very important role. Generally speaking, there are three different ways of smelling: slow and deep, quick and deep and sequence of short and little smells. Smelling slowly and deeply allows the perception of light substances because this generates, both in the nose and in the glass, light turbulences that do not “disturb” heavier substances. Smelling quickly and deeply generates a more intense turbulence, both in the nose and in the glass, and this will promote the perception of the heavier substances. Lastly, a sequence of quick and short smells will contribute to “amplify” the perception of aromas because this action will generate subsequent turbulences on the nose while encouraging the perception of all volatile substances. This smell technique is the one generally used by animals, such as dogs, when they have to smell something and perceive odors. These three smell techniques will be used in all the phases that will be discussed later.

 The qualities evaluated during the olfactory analysis are usually four: intensity of aromas, that is their strength, persistence, that is the time they can be perceived before disappearing, finesse or quality, that is the elegance, agreeability of aromas and, lastly, the analytical and nominal description of every perceived aroma.

 The olfactory evaluation begins by holding the glass, without moving or swirling it, and the content will be smelt: in this phase are going to be evaluated the light molecules which easily volatilize from the glass. This first phase also allows the perception of all light and delicate aromas and that would be covered or dispersed during the subsequent phases. In this phase will be perceived defective aromas and olfactory faults as well. After this, the glass will be swirled in order to promote oxygenation, therefore volatilization, of heavier substances and then the content of the glass will be smelt again. In this second phase will be probably perceived aromas that was not perceivable in the previous phase. In case a wine's aroma would be very light or “dumb” no matter the glass has been vigorously swirled, it will be needed to vigorously shake the glass in order to promote the volatilization of its aromas. Cover the glass with a hand and shake it vigorously: the “lazy” aromas should be now perceived. Finally, the last evaluation of aromas can be done when the glass is empty and there are few drops of wine in the bottom. There are molecules which are particularly heavy and need vigorous oxygenations in order to get volatilized. The scarce quantity of wine remained in the bottom of the glass will be heavily exposed to oxygen and this will finally promote the volatilization of all those heavier molecules. In consideration of this, it is a good idea to smell a glass after it has been emptied in order to detect further and useful information about wine's aromas, of course, this final evaluation can be done at the end of the organoleptic analysis of a wine and therefore will be the very last operation to be done.

 Finally, it should be remembered of the risk of getting adapted to aromas and this would compromise and vanish all the efforts done during the olfactory evaluation of a wine. After having smelt a wine for three or four minutes, remember to take some little breaks of about one or two minutes before resuming the olfactory evaluation.

 Like we said, aromas are originated by some chemical volatile substances, that is by substances having the property of volatilizing and therefore to evaporate. Chemical compounds having this property belong to specific categories where the most important ones are alcohols, aldehydes, acids, esters, ketones and terpenes. Covering the subject of chemical aspects of smells would go beyond the main purpose of this report and, therefore, for the moment, it will be enough to know smells are produced by some chemical volatile substances.

 Thanks to the many experiences acquired from analytical tastings as well as researches done on wine's aromas, it has been possible to define a specific classification system of aromas in proper categories, universally accepted in the wine world, and each of them contains specific aromas usually found in wine. The system which is most commonly used in classifying wine's aromas usually defines ten different categories as follows:

• animal - includes “musky” aromas related to certain grapes as well as smell of meat, game and odorous substances produced and emitted by some animals
• balsamic - includes aromas which denote a “balsamic” character such as resin
• woody - includes aromas produced and originated by the permanence of wine in cask, that is aromas that were passed from wood to wine
• chemical - includes aromas having a chemical nature, such as acids, sulfurous smells and so on
• burnt - includes smells that resembles those or burnt, toasted, smoky and charred
• ethereal - include smells produced by alcohol, those of ethyl's nature, produced by esters of fatty acids or enamel as well as smells produced by wine's fermentation
• floral - includes aromas that resemble the ones of flowers
• fruity - includes aromas that resemble the ones of fruits
• spicy - includes aromas that resemble the ones of spices and aromatic herbs
• vegetal - includes typical aromas of vegetal substances, such as pepper, grass, hay and so on

 The above categories are particularly useful during the olfactory evaluation of a wine and represent a valid and consistent reference in the identification of specific aromas. Moreover, wine's aromas are classified according to their specific origin or, in more specific terms, according to their level of development and period of wine's life. These categories are three, as follows:

• primary aromas - aromas belonging to this category are also defined as varietal and represent the typical aromas of the grapes used to produce a certain wine, that is the aromas that usually and typically develop in specific grapes
• secondary aromas - also known as fermentative, the aromas belonging to this category are the ones that developed as a consequence of the alcoholic fermentation
• tertiary aromas - also known as post-fermentative, the aromas belonging to this category develop as a consequence of wine's aging, typically after some years

 Primary aromas are originated by certain grapes used to produce wine and these aromas are usually typical and allow, in general terms, to recognize and tell that grape as soon as the wine is smelt. Generally speaking, primary aromas are produced by the so called “aromatic grapes”, that is from those grapes having a rich and high quantity of aromatic substances, and whose aroma usually resembles the one of grape, such as Muscat blanc and Gewürztraminer. Grape's aromas are found in skins and, because of fermentation, they are passed to the must that will be subsequently transformed into wine. Every grape has a primary aroma and every grape will give wine particular aromatic characteristics, however there are grapes which have higher aromatic substances than others as well as different aromatic intensities. Thanks to primary aromas it is usually possible to recognize and to tell the grape used to make a wine, therefore its typical aspects, and, last but not the least, the area where the wine comes from, the cultivation technique and the level of grape's ripeness at the moment of harvest. Finally, primary aromas can also be altered by certain wine making techniques in order to enhance or diminish the typical character of grapes.

 Secondary aromas are the result of the fermentative processes and of the development of some primary aromas because of the alcoholic fermentation. Alcoholic fermentation begins as soon as the grapes are pressed and originates aromas that can be defined as pre-fermentative and they will evolve and develop in the course of the alcoholic fermentation. This process, whose purpose is to transform sugar into alcohol by means of yeasts, produces alcohol which, in turn, works as an excipient for aromatic substances, as well as giving carbon dioxide, which promote the development of some aromas, and other byproducts that can be source of aromas in a wine and, lastly, the aromas produced by yeasts because of the effects of the transformation of sugar into alcohol. Aromas produced during the so called malolactic fermentation, that is the process that transforms malic acid into lactic acid with the result of giving a more “round” wine, belong to this category as well.

 Aromas which are typically developed in consequence of fermentation are usually of ripe fruits, jams, flowers, aromatic herbs and however those aromas that cannot be considered as primary, that is typical aromas of grapes. Alcoholic fermentation also has the property of revealing in a very clear way wine's primary aromas, as well as amplifying other aromas; that's also why it is said that “primary aromas are hidden in grapes, alcoholic fermentation reveals them”.

 The aromas belonging to this category are the ones which developed and evolved during the phases of wine's refinement and aging, including the aromas that are originated during the wine's stay in the cask. These aromas develop as a consequence of oxidative and reductive processes, that is the processes that takes place in absence of oxygen and it is, in fact, the opposite of oxidization. The development of the so called “tertiary aromas” is truly complex and, besides being produced by oxidization and reductive phenomena, they also develop as a consequence of acetilization, esterification and etherification as well as for the transformation of tannins. During these phases, come components, such as alcohol, acids, esters, ethers and phenolic compounds, are determinant for the proper development of these processes.

 As a matter of fact, wine's refinement and aging transform primary and secondary aromas while giving them a more complex and mature character and, sometimes, some aromas are transformed in a way that it is almost impossible to associate them to their original aromas. This process also has the important effect of “tying” the olfactory profile of wine.