Refinement and Aging of Wine

 The wish of having lots of bottles, neatly arranged in a rack or shelf, sheltered from light and heat, to be uncorked in special occasions, after some years, is probably the dream of every wine lover. To own a cellar, an almost sacred room, where bottles of wine can be stored and left to rest, or better to say, to refine, that magic place to which entrusting young wines in order to be taken to a magic journey that will give us back more austere and mature wines, is a dream every wine lover has. The idea of taking a bottle of wine from our cellar, a bottle that was left to rest for some years, is just like meeting an old and dear friend that we do not meet since a very long time and it has a lots of things to tell and that we joyfully hear, enchanted by the wonders it met in the course of its journey.

 The problem here is that dreams not always turn into reality, sometimes there are elements that make things hard and what we wish is not what we get. Indeed, when we talk about wine's storage, having a good cellar, even built with the best possible criteria, is not enough to ensure our wines a long and prosperous life. To be honest, the availability of a personal cellar, built according the best conditions and guidelines, is a luxury that not everyone can afford. Often, the majority of wine lovers arrange rooms of their houses in order to be used as cellars, after all, when nothing good comes, we take what we have at hand. However, we should consider something about storing wines: owning a cellar is not the only key for success, we also need proper wines, that is wines expressly produced with grapes suited for aging, as well as other factors that change every year, production area and, last but not the least, the ability and skill of the wine maker and, lastly, conditions set by Mother Nature. Often, wines suited for the refinement process are expressly built and made by producers with this specific goal in mind. Lastly, not every wine can be aged or refined for years in order to improve its quality, there are many wines, lots of wines, that cannot go beyond two years of aging, sometimes even less, even in case they were left in the best cellar. A cellar, a good cellar, is not enough for the aging of wine, we need a wine suited for aging first.

 As soon as a bottle of wine has been bought, the wine lover often ask himself or herself whether it would be good to drink that wine or it would be better to wait for some years instead. There is something that we can take for granted: there is no exact rule that can tell us the exact moment when the wine in a bottle has reached its very best refinement or aging condition in order to determine the best time possible for uncorking it. However, there are some factors that will allow a good level of expectation and approximation and will allow us to determine when uncorking a bottle in the vicinity of its best time; with a little of fortune as well, we will also be able to uncork a specific bottle in its very best time. The first thing to consider is that, generally speaking, wines are released by wine producers in the time they believe they are ready to be drunk, that is in the time wine producers think the wine already has good qualities and that can be enjoyed without any refinement time or aging. This is mainly true for white wines, because they generally do not stand long aging times, with few exceptions. The majority of white wines tend to lose their aromatic “freshness” when aged, their typical fruit and fresh flowers aromas, something which is welcomed and enjoyed in these wines, tend to flatten with time and they turn into less interesting and enjoying aromas of cooked fruit. Compared to red wines, which can stand to about longer aging times, white wines that can be successfully aged are just few.

 In general terms, the main factors which determine the success of aging in a wine are:

• Species of the grape - Every species of grape has proper characteristics and different quantity of element from each other. This is also determined by the time of harvesting: a ripe grape is rich in sugar and poor in acids, an unripe grape is rich in acids and poor in sugar. Particularly, there are grapes which naturally have greater quantities of phenolic compounds than others, this factor is very important for a long and good aging. Wines produced with red grapes, having a greater quantity of phenolic compounds than white grapes, can stand, also thanks to this characteristic, to a longer aging time
• Wine making techniques - Wines that can stand a long aging time must be expressly created with this goal in mind and this is mainly the result of the wine making technique used to produce a wine. For example, long time of maceration of skins in must, gives a higher phenolic compound's extraction, as well as a more pronounced astringency, a factor that allows wine to stand a pretty long aging time but this also makes the wine unpleasing, to be precise, astringent, and it would be not really good in case it is drunk in its young age. Other factors dependent on wine making techniques and that could allow good aging conditions, include casks which add phenolic compounds, that is tannins, to the wine
• Conditions of the year - This factor, uniquely determined by the will and the goodness of Mother Nature, actually has a strong, and sometimes irremediably bad, influence on grapes' quality, it could make them exceptional or just very bad. However it should be noticed that the many improvements of enology allowed, in some extents, to minimize the unfavorable effects of the year and therefore there can be made “decent” products from very bad grapes. Of course, an excellent matter, that is good grapes, can make excellent products without using any excessive or vigorous remedies, obviously, this is truly beneficial to the quality of wine and, lastly, to its potential capacity of development and refinement with time
• Storage conditions - A good wine, made with the best intents and matters, as well as with the best techniques for a long aging time, can be easily ruined in case it is stored in unfavorable places and under unfavorable conditions. Light, excessive change of temperature, too high or too low, and oxygen are just few of the unfavorable factors that can determine a sure failure in storing a wine
• Preservative components of wine - Like we said for grapes, an essential matter for wine making, there are some components, naturally contained in grapes or voluntarily added during the wine making process, that can allow wine to stand longer aging times and therefore can allow the wine to better refine and develop. We already said phenolic compounds, that is tannins, are a factor that ensure a good storage and aging. Other components having a preservative effect in wine are sugar and acid. Passito (sweet) wines and late harvest, usually having high quantity of sugar, can stand longer aging times because of the preservative effect of sugar.

 Speaking in more specific terms, also trying to offer some practical indications, there are few wines, compared to the total amount of wine produced in the world and released in the market, which is suited for refinement and to properly age in a cellar. The majority of wine is released in the market by producers in the time they think it is ready to be drunk in order to better appreciate its best characteristics. White wines and rose wines, with very few exceptions, are usually to be consumed as soon as possible, red wines can sometimes be refined and aged for some years. Concerning red wines, it should be noticed the producer itself could have been aged the wine for some years in its cellar, either because of some specific wine laws or because of the necessity of making a specific style of wine. However, wine can be bought with the specific goal of storing it in the cellar for some years in order to benefit from aging, once again, wines suited for aging must have specific characteristics, such as the kind of grape used to make them as well as proper wine making techniques that allow wine to begin the magic journey of aging. As an example, we can consider a wine produced with Cabernet Sauvignon grape. The average aging time that wines produced with this grape can stand to, can usually vary from 4 to 20 years. A wine produced with this grape, very high yield, short time of maceration of the skins, coarse wine making techniques, despite of the good longevity of Cabernet Sauvignon, this wine will not even stand to the minimal 4 years usually expected from this grape. On the contrary, a wine produced with Cabernet Sauvignon, very low yield, which gives a grape rich in components and matters, long times of maceration of the skins, that is a high extraction of phenolic compounds, proper wine making techniques, can give a wine that can age for more than 20 years, of course, in case it is stored in proper conditions. Obviously, a wine produced in this way requires higher costs for the producers and, of course, for the buyer too. It would be a good idea if producers, that know their products better than anyone else, would indicate in wine labels the suggested aging time or, at least, the number of years the wine can be aged before it declines. This kind of expectations are hard to express for everyone, including producers, however the producers, better than anyone else, could provide consumers these kind of information as a sign of honesty and in the sake of a better information and appreciation. Honestly, there are some producers that indicate in their wine labels the expected number of years the wine can be aged; we can just praise and admire these producers; however, these are just indicative information but they surely are something consumers can rely on as a reference.

 Table shows indicative aging times for some kind of grapes. However, it should be considered that times greatly vary according to the condition of the vintage, production area, wine making practices as well as storing conditions.

 Our knowledge about the way white wines evolve and develop with time is not very high: everything we know mainly depend on experience and by directly observing the wine instead of scientific investigations. The most evident factor that emerges in the development of white wines is the change of color, from straw yellow which can turn with time to amber and then to brown. This process is probably the result of a slow oxidation of the phenolic elements contained in white wine, even though in small quantities if compared to red wines. Occasionally white wines can also develop a sediment and this usually happens with a lesser frequency than red wines, as well as in small quantities.

 The direct connection about the quantity of phenolic compounds and aging time, common in red wines, is scarcely applicable to white wines because, as an example, wines produced with Riesling grape are usually more longeval than the ones produced with Chardonnay grape, despite the fact the latter grape contains a higher quantity of phenolic compounds. However it should be noticed that Riesling contains a higher quantity of acid than Chardonnay and, like we said, acid favors longer aging times because of its preservative effect.

 Moreover, it was noticed that white wines fermented in cask usually stand to longer aging times, this is probably because of the greater quantity of tannins and phenolic compounds transferred from wood to wine, if compared to the same wines produced with the very same grapes and fermented in stainless steel container and subsequently refined in cask. Late harvests, passito (sweet) wines, whose grapes are affected by Botrytis Cinerea, or noble rot, usually have surprisingly long aging times because of the high content of sugar which is a preservative.

 The main factors noticed in red wines after long periods of aging are the change of color and the possible presence of a certain quantity of sediment in the bottom of the bottle. Both phenomena are dependent on the variation and change of phenolic compounds, responsible for the color in red wine, as well as for the effect of the acid contained in the wine and for the effects of oxygen. In these specific conditions and with time, phenolic compounds in wine tend to polymerize, that is to aggregate in bigger and more complex molecules. As the phenolic compounds molecules reach a specific size, their weight increases as well and, as they cannot stay in solution with wine anymore, precipitate to the bottom of the bottle and form a sediment. This process subtracts some colorant components to the wine and the color progressively turns into orange-red or brick color.

 During this process, the taste and the aromas of a red wine change and evolve to a more austere and complex qualities, this is also favored by the small and precious quantity of oxygen that gets into the bottle through the cork, as well as for the effects of reduction because of the small quantity of oxygen contained in the bottle. Technically, the processes that determine the development of these “new” aromas are also the result of the oxidation of aldehydes and to the development of esters because of the combination of the acids contained in the wine with alcohol. This is also the reason why a red wine aged for a long time is usually less acid than a young wine.

 The velocity at which these phenomena take place and develop, depends on many factors, including the temperature of storage, the conditions of the cork, the quantity of oxygen contained in the bottle, wine's acidity and the quantity of sulfur dioxide dissolved in the wine.

 Sparkling wines produced with the Charmat or Martinotti method should be usually consumed within one year from their purchase. Things are slightly different for sparkling wines produced with the classic method or “méthode Champenoise”. A sparkling wine produced with the classic method can age and improve its qualities, even for tens of years, until it is being “disgorged”, that is as long as the bottle it is not opened and therefore ending the long refining period of the wine in yeasts. The secondary fermentation in the bottle, as well as the increase of internal pressure, saturate the bottle with carbon dioxide and therefore there will not be any oxygen in it. In this condition oxidative processes cannot take place; the wine can be aged in this way for many and many years. As the bottle is being opened, carbon oxide is expelled and air gets in, that is oxygen, and it is subsequently trapped in the bottle as it gets capped with a cork. This oxygen, even though is in small quantity, starts a slow but inexorable process of oxidation. A sparkling wine produced with the classic method should be consumed within two or three years from its purchase, however it is good to wait for at least six months, even better one full year, from the date of disgorgement. Serious producers that make sparkling wine with the classic method always indicate the date of disgorgement in the label in order to give the consumer a precise information on when the bottle should be opened and therefore the wine can be appreciated at its best.

 However there are exceptions to the above rule: there are cases in which some exceptional vintages of Champagne, Franciacorta and other sparkling wines produced with the classic method, were in perfectly good conditions and successfully developed even after many years from the disgorgement date. It should be noticed, however, that these kind of wines tend to lose their freshness with time, as well as their vivacity and effervescence. Oxidation processes, just like for white wines, change the color and transform it into golden yellow and the taste slightly flattens although it also gets indisputably more complex. This simply is, like always, a subjective matter of taste.

 Light, drastic changes of temperature, unfavorable temperatures of storage and oxygen are all factors that can deteriorate chemical and organoleptic qualities of a wine during its period of aging.

 Long periods of exposition to direct light, in particular to sunlight, determine chemical and physical changes in wine, as well as changes in organoleptic qualities. Sunlight, because of ultra-violet rays, favors the development of free radicals in wine and this accelerates the oxidation process. Light also affects the taste of wine. The so called “reduced” aromas and tastes can be accentuated by the photochemical effect of light, this condition is also known as “taste of light”, “taste of sun” or “taste of bottle”. A wine that developed a “taste of light” can be easily recognized because of its aromas and flavors of garlic and sweat and, most of the times, the wine seems to have lost its frankness. Wines which are particularly affected by this phenomena are mainly white, lightly sparkling wines and sparkling wines. Sheltering wine from light is therefore an essential factor for a proper storage and aging. The color of the bottle is essential in order to prevent the passage of light and in order to prevent any possible damage to the wine: the best bottles are the ones having a dark green or dark brown color because they may work as a filter for light. Deprecable is the usage of white, colorless and transparent bottles because they allow a full passage of light: it is funny to see this kind of bottle is mainly used for white and rose wines, that is those kind of wines that need the best protective condition against light rays.

 Temperature greatly affects the preservability of wine. High temperatures accelerate the aging process and, even though this could be seen as a great advantage, the idea of being able to age our wines, for example, in half of the time could seem as advantageous, indeed, a wine which ages too fast also lose its best qualities and it will tend to be more coarse and it will deteriorate more rapidly. A long and slow aging is what makes a wine elegant, austere and exceptional, it is what allows wine to develop and evolve better. The slow and correct refinement is guaranteed by a proper temperature of storage, and it can usually range from 10° C (50° F) to 15° C (59° F), however it should be noticed that serious problems for wine begins at temperature higher than 25° C (77° F) because at these temperatures volatile components will be irremediably destroyed. Storing a wine at very low temperature, below 0° C, (32° F) are unfavorable and dangerous as well. At these temperatures, particularly below -4° C, (24.8° F) light wines, the ones having small quantities of alcohol, begin to freeze and this will also increase the volume in the bottle and the cork will be expelled out.

 Sudden and wide changes of temperature during the period of storage are to be avoided anyway: this may happen, for example, during the change of the seasons and in rooms having a bad or insufficient isolation from these events. As the temperature increases, the wine contained in the bottle will expand and will probably spill out from the bottle through the cork. As soon as the temperature gets lower, the wine in the bottle will contract and this will originate an internal depression whose effect will be to suck air from the cork. Every expansion of the wine, and the consequent spilling of wine from the bottle, actually decreases the quantity of wine in the bottle by increasing, on the contrary, the free space that will be occupied by the sucked air; this process will favor the oxidation of wine as well as accelerating the aging of wine and both effect will completely ruin the wine. Lastly, the expelled wine from the bottle because of a high temperature, will be trapped between the cork and the capsule and, because of its small quantity, this wine will rapidly oxidate and it can also be transformed into vinegar and therefore the cork will be contaminated as well as the neck of the bottle.

 Even humidity plays an important role in the storage of wine. Storage rooms having a low level of humidity tend to dry corks and, as a consequence, they shrink and compromise their fundamental hermetic property therefore allowing the wine to get out as well as the passage of air. However a level of humidity too high would damage the labels of the bottles as well as developing molds between the cork and the capsule. The ideal level of humidity for a storage room should be of about 70%.

 Lastly, the position at which the bottle is kept plays an important role in a successful aging and storage. Generally, bottles should be kept in a horizontal position in order for the wine to be in contact with the cork and to prevent the cork to shrink. In case the cork shrinks, it favors spillage of wine as well as favoring air to get into the bottle. However it should be noticed that fortified wines, that is wines having a high content of alcohol, could damage and disaggregate the cork within few years because of the effect of alcohol. This effect happens anyway in every wine which has been aged for very long period of times, 15 - 20 years, and that was kept in horizontal position. Talking about the position at which the bottles should be kept during the aging period, there is a new theory that suggests not to keep the bottles in a horizontal position, but they should be kept in a slightly inclined position in order to allow both the wine and the internal bubble of air to be in contact with the cork. This position would allow the cork to be moistened by wine and would favor the expulsion of air from the bottle instead of wine in case the temperature gets higher.