The
aging of wineWine is an alcoholic beverage typically made of fermented grape juice. The natural chemical balance of grapes is such that they can ferment without the addition of sugars, acids, enzymes or other nutrients. Wine is produced by fermenting crushed grapes using various types of yeast. Yeast consumes...
, and its ability to potentially improve in quality, distinguishes wine from most other consumable goods. While wine is perishable and capable of deteriorating, complex chemical reactions involving a wine's sugars, acids and phenolic compounds (such as tannins) can alter the aroma, color,
mouthfeelMouthfeel is a product's physical and chemical interaction in the mouth, an aspect of food rheology. It is a concept used in many areas related to the testing and evaluating of foodstuffs, such as wine-tasting and rheology. It is evaluated from initial perception on the palate, to first bite,...
and taste of the wine in a way that may be more pleasing to the taster. The ability of a wine to age is influenced by many factors including grape variety,
vintageVintage, in wine-making, is the process of picking grapes and creating the finished product. A vintage wine is one made from grapes that were all, or primarily, grown and harvested in a single specified year. In certain wines, it can denote quality, as in Port wine, where Port houses make and...
, viticultural practices, wine region and
winemakingWinemaking, or vinification, is the production of wine, starting with selection of the grapes or other produce and ending with bottling the finished wine. Although most wine is made from grapes, it may also be made from other fruit or non-toxic plant material...
style. The condition that the wine is kept in after bottling can also influence how well a wine ages and may require significant time and financial investment.
History
The Ancient Greeks and Romans were aware of the potential of aged wines. In Greece, early examples of dried "straw wines" were noted for their ability to age due to their high sugar contents. These wines were stored in sealed
earthenwareEarthenware is a common ceramic material, which is used extensively for pottery tableware and decorative objects. Although body formulations vary between countries, and even between individual makers, a generic composition is 25% ball clay, 28% kaolin, 32% quartz, and 15% feldspar. Earthenware is...
amphorae and kept for many years. In Rome, the most sought after wines—Falernian and Surrentine—were prized for their ability to age for decades. In the Book of Luke, it is noted that "old wine" was valued over "new wine" . The Greek physician
GalenAelius Galenus or Claudius Galenus , better known as Galen of Pergamum , was a prominent Greek physician and philosopher and probably the most accomplished medical researcher of the Roman period. His theories dominated and influenced Western medical science for well over a millennium...
wrote that the "taste" of aged wine was desirable and that this could be accomplished by heating or smoking the wine though, in Galen's opinion, these artificially aged wines were not as healthy to consume as naturally aged wines.
Following the Fall of the Roman Empire, appreciation for aged wine was virtually non-existent. Most of the wines produced in northern Europe were light bodied, pale in color and with low alcohol. These wines did not have much aging potential and barely lasted a few months before they rapidly deteriorated into
vinegarVinegar is an acidic liquid processed from the fermentation of ethanol in a process that yields its key ingredient, acetic acid. It also may come in a diluted form. The acetic acid concentration typically ranges from 4 to 8 percent by volume for table vinegar and higher concentrations for pickling...
. The older a wine got the cheaper its price became as merchants eagerly sought to rid themselves of aging wine. By the 16th century, sweeter and more alcoholic wines (like Malmsey and
SackSack is an antiquated wine term referring to white fortified wine imported from mainland Spain or the Canary Islands. There were sack of different origins such as:* Canary sack from the Canary Islands,* Malaga sack from Málaga,...
) were being made in the Mediterranean and gaining attention for their aging ability. Similarly,
RieslingRiesling is a white grape variety which originates in the Rhine region of Germany. Riesling is an aromatic grape variety displaying flowery, almost perfumed, aromas as well as high acidity. It is used to make dry, semi-sweet, sweet and sparkling white wines. Riesling wines are usually varietally...
from Germany with its combination of acidity and sugar were also demonstrating their ability to age. In 17th century two innovations occurred that radically changed the wine industry's view on aging. One was the development of the cork and bottle which allowed producers to package and store wine in a virtually air-tight environment. The second was the growing popularity of fortifying wines such as Port, Madeira and Sherries. The added alcohol was found to act as a preservative, allowing wines to survive long sea voyages to
EnglandEngland is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west and the North Sea to the east, with the English Channel to the south separating it from continental...
, The Americas and the East Indies. The English, in particular, were growing in their appreciation of aged wines like Port and
ClaretClaret is a name primarily used in British English for red wine from the Bordeaux region of France.-Usage:Claret derives from the French clairet, a now uncommon dark rosé and most common style of wine exported from Bordeaux until the 18th century...
from Bordeaux. Demand for matured wines had a pronounced effect on the wine trade. For producers, the cost and space of storing barrels or bottles of wine was prohibitive so a merchant class evolved with warehouses and the finances to facilitate aging wines for a longer period of time. In regions like Bordeaux, Oporto and Burgundy, this situation dramatically increased the balance of power towards the merchant classes.
What wine can age?
Despite the well known saying that
"All wine improves with age", only a few wines will actually have the ability to significantly improve with age. Master of Wine Jancis Robinson notes that only around the top 10% of all red wine and top 5% of all white wines can improve significantly enough with age to make drinking more enjoyable at 5 years of age than at 1 year of age. Additionally, Robinson estimates, only the top 1% of all wine has the ability to improve significantly after more than a decade. It is her belief that more wine is consumed too old, rather than too young, and that the great majority of wines start to lose appeal and fruitiness after 6 months in the bottle.
In general, wines with a low
pHpH is a measure of the acidity or basicity of a solution. It is defined as the cologarithm of the activity of dissolved hydrogen ions . Hydrogen ion activity coefficients cannot be measured experimentally, so they are based on theoretical calculations...
(such as
Pinot noirPinot noir is a red wine grape variety of the species Vitis vinifera. The name may also refer to wines produced predominantly from Pinot noir grapes...
and
SangioveseSangiovese is a red Italian wine grape variety whose name derives from the Latin sanguis Jovis, "the blood of Jove". Though it is the grape of most of central Italy from Romagna down to Lazio, Campania and Sicily, outside Italy it is most famous as the main component of the Chianti blend in...
) have a greater capability of aging. With red wines, a high level of flavor compounds, such as
phenolicPhenolic may refer to*Polyphenol, a large class of natural compounds found in colorful plants and with laboratory evidence of antioxidant activity*Phenol , a colorless crystalline solid and aromatic compound...
s (most notably tannins), will increase the likelihood that a wine will be able to age. Wines with high levels of phenols include
Cabernet SauvignonCabernet Sauvignon is one of the world's most widely recognized red wine grape varieties. It is grown in nearly every major wine producing country among a diverse spectrum of climates from Canada's Okanagan Valley to Lebanon's Beqaa Valley...
, Nebbiolo and Syrah. The white wines with the longest aging potential tends to be those with a high amount of extract and acidity. The acidity in white wines plays a similar role that tannins have with red wines in acting as a preservative. The process of making white wines, which include little to no skin contact, means that white wines have a significantly fewer amounts of phenolic compounds (though barrel
fermentationThe process of fermentation in wine is the catalyst function that turns grape juice into an alcoholic beverage. During fermentation yeast interact with sugars in the juice to create ethanol, commonly known as ethyl alcohol, and carbon dioxide...
and oak aging can impart some phenols). Similarly, the minimal skin contact with
roséA rosé wine has some of the color typical of a red wine, but only enough to turn it pink. The pink color can range from a pale orange to a vivid near-purple, depending on the grapes and wine making techniques.-Skin contact:...
wine limits their aging potential.
After aging at the winery most wood-aged Ports, Sherries,
Vins doux naturels, Vins de liqueurA vin de liqueur is a sweet fortified style of French wine. The term "vin de liqueur" is also used by the European Union to refer to all fortified wines. These wines are similar to vins doux naturels but are fortified just prior to fermentation and are sweeter, with more flavor influence from the...
, basic level
Ice wineIce wine is a type of dessert wine produced from grapes that have been frozen while still on the vine. The sugars and other dissolved solids do not freeze, but the water does, allowing a more concentrated grape must to be pressed from the frozen grapes, resulting in a smaller amount of more...
s and sparkling wines are bottled when the producer feels that they are ready to be consumed. These wines are ready to drink upon release and will not benefit much from aging. Vintage Ports and other bottled-aged Ports & Sherries will benefit from some additional aging, as can vintage Champagne. In 2009, a 184-year-old bottle of
Perrier-JouëtPerrier-Jouët is a Champagne producer based in the Épernay region of Champagne. The house was founded in 1811 by Pierre-Nicolas-Marie Perrier-Jouët, and produces both vintage and non-vintage cuvee, with its prestige label named Belle Epoque...
was opened and tasted, still drinkable, with notes of "truffles and caramel", according to the experts.
Wines with little to no aging potential
A guideline provided by Master of Wine
Jancis RobinsonJancis Mary Robinson OBE, MW is a British wine critic, journalist and editor of wine literature. She currently writes a weekly column for the Financial Times, and writes for her website jancisrobinson.com...
- German QBAs
- Asti and Moscato
Moscato can have several meanings see:*Muscat *Judah Moscato...
Spumante
- Rosé and blush wines like White Zinfandel
White Zinfandel, often abbreviated as White Zin, is an off-dry to sweet, pink-colored blush wine. White Zinfandel is made from the Zinfandel wine grape, which would otherwise produce a bold and spicy red wine. As such, it is not a grape variety but a method of processing Zinfandel grapes...
- Branded wines like Yellow Tail
Yellow Tail is a brand of wine produced by Casella Wines Pty Ltd. Casella wines is based in Yenda, Australia, which has a population of approximately 1000 people. The Casella family has produced wines since the 1820s in Italy...
, Mouton CadetMouton Cadet is the brand name of a popular range of modestly priced, generic Bordeaux wines, considered Bordeaux' most successful brand. Created by Baron Philippe de Rothschild of the Rothschild banking dynasty, the wine named after his premier cru vineyard Château Mouton Rothschild, Mouton Cadet...
, etc
- European table wine
Table wine is a wine term which is used in two different meanings in different countries: to signify a wine style and as a quality level within wine classification....
- American jug & box wine
A box wine is a wine packaged as a Bag-In-Box. Such packages contain a plastic bladder protected by a box, usually made of corrugated fiberboard.-History and culture:...
- Inexpensive varietal
"Varietal" describes wines made primarily from a single named grape variety, and which typically displays the name of that variety on the wine label. Examples of grape varieties commonly used in varietal wines are Cabernet Sauvignon, Chardonnay and Merlot...
s (with the possible exception of Cabernet SauvignonCabernet Sauvignon is one of the world's most widely recognized red wine grape varieties. It is grown in nearly every major wine producing country among a diverse spectrum of climates from Canada's Okanagan Valley to Lebanon's Beqaa Valley...
)
- The majority of Vin de pays
Vin de pays is a French term meaning "country wine". Vins de pays are a step in the French wine classification which is above the table wine classification, but below the VDQS and Appellation d'origine contrôlée classifications...
- All Nouveau wines
- Vermouth
Vermouth is a fortified wine, flavoured with aromatic herbs and spices such as cardamom, cinnamon, marjoram and chamomile. Some vermouth is sweetened; however, unsweetened, or dry, vermouth tends to be bitter...
- Basic Sherry
Sherry is a fortified wine made from white grapes that are grown near the town of Jerez, Spain. In Spanish, it is called vino de Jerez. Sherry is regarded by some wine critics as "underappreciated" and a "neglected wine treasure"....
, Ports
Wines with some aging potential
A guideline provided by Master of Wine Jancis Robinson. Note that vintage, wine region and winemaking style can influence a wine's aging potential so Robinson's suggestion of years are very rough estimates of the most common examples of these wines.
- Botrytized wines (5–25 yrs)
- Chardonnay
Chardonnay is a green-skinned grape variety used to make white wine. It is believed to have originated in the Burgundy wine region of eastern France but is now grown wherever wine is produced, from England to New Zealand...
(2–6 yrs)
- Riesling
Riesling is a white grape variety which originates in the Rhine region of Germany. Riesling is an aromatic grape variety displaying flowery, almost perfumed, aromas as well as high acidity. It is used to make dry, semi-sweet, sweet and sparkling white wines. Riesling wines are usually varietally...
(2–30 yrs)
- Hungarian Furmint
Furmint is a variety of wine grape from the Pontian Balcanica branch of Vitis vinifera, used for white wines. The name Furmint is taken from the word "froment" for the wheat-gold color of the wine it produces. The origins of the variety are unclear; some believe it came from southern Italy, while...
(3–25 yrs)
- Loire Valley
The Loire Valley wine region includes the French wine regions situated along the Loire River from the Muscadet region near the city of Nantes on the Atlantic coast to the region of Sancerre and Pouilly-Fumé just southeast of the city of Orléans in north central France. In between are the regions of...
Chenin blancChenin blanc , is a variety of white wine grape variety from the Loire valley of France. Its high acidity means it can be used to make everything from sparkling wines to well-balanced dessert wines, although it can produce very bland, neutral wines if the vine's natural vigor is not controlled...
(4–30 yrs)
- Hunter Valley Semillon
Sémillon is a golden-skinned grape used to make dry and sweet white wines, most notably in France and Australia.-History:The history of the Sémillon grape is hard to determine. It is known that it first arrived in Australia in the early 1800s and by the 1820s the grape covered over 90 percent of...
(6–15 yrs)
- Cabernet Sauvignon
Cabernet Sauvignon is one of the world's most widely recognized red wine grape varieties. It is grown in nearly every major wine producing country among a diverse spectrum of climates from Canada's Okanagan Valley to Lebanon's Beqaa Valley...
(4–20 yrs)
- Merlot
Merlot is a red wine grape that is used as both a blending grape and for varietal wines. Merlot-based wines usually have medium body with hints of berry, plum, and currant...
(2–10 yrs)
- Nebbiolo (4–20 yrs)
- Pinot noir
Pinot noir is a red wine grape variety of the species Vitis vinifera. The name may also refer to wines produced predominantly from Pinot noir grapes...
(2–8 yrs)
- Sangiovese
Sangiovese is a red Italian wine grape variety whose name derives from the Latin sanguis Jovis, "the blood of Jove". Though it is the grape of most of central Italy from Romagna down to Lazio, Campania and Sicily, outside Italy it is most famous as the main component of the Chianti blend in...
(2–8 yrs)
- Syrah (4–16 yrs)
- Zinfandel
Zinfandel is a variety of red grape planted in over 10 percent of California vineyards. DNA fingerprinting revealed that it is genetically equivalent to the Croatian grape Crljenak Kaštelanski, and also the Primitivo variety traditionally grown in the "heel" of Italy, where it was introduced in the...
(2–6 yrs)
- Classified Bordeaux (8–25 yrs)
- Grand Cru Burgundy (8–25 yrs)
- Aglianico
Aglianico is a black grape grown in the Campania and Basilicata regions of Italy. The vine originated in Greece and was brought to Campania by Greek settlers. The name may be a corruption of Vitis hellenica, Latin for "Greek vine"...
from TaurasiTaurasi and Taurasi riserva are red, still Italian wines based principally on the Aglianico grape variety produced in the Province of Avellino in the Campania region. They were awarded Denominazione di Origine Controllata status in 1970 and Denominazione di Origine Controllata e Garantita status...
(4–15 yrs)
- Baga
Baga is a red Portuguese wine grape planted primarily in the Bairrada DOC. As a varietal, Baga produces tannic wines with high acidity....
from Bairrada (4–8 yrs)
- Hungarian Kadarka
Kadarka or Gamza is an old red wine grape varietal. It is popular in Hungary, where it was introduced with the Turkish occupation, and Bulgaria, where it is known as гъмза Gamza. It is an important constituent of the Hungarian red cuvée Bull's Blood of Eger or Szekszárd...
(3–7 yrs)
- Bulgarian Melnik (3–7 yrs)
- Croatian Plavac Mali
Plavac Mali, a cross between ancestral Zinfandel and Dobričić grapes, is the primary red wine grape grown along the Dalmatian coast of Croatia. The name refers to the small blue grapes that the vines produce: in Croatian plavo means blue and plavac refers to 'what is blue'; mali means small...
(4–8 yrs)
- Russian Saperavi
Saperavi is an acidic, teinturier-type grape variety native to Georgia, where it is used to make many of the region's distinctive wines, along with the Alexandreuli and Rkastiteli varieties. Leaves are 3-lobed, large, and roundish...
(3–10 yrs)
- Madiran Tannat
Tannat is a red wine grape, historically grown in South West France in the Madiran AOC and is now one of the most prominent grapes in Uruguay, where it is considered the "national grape". It is also grown in Argentina, Australia, Brazil and in Italy's Puglia region where it is used as a blending...
(4–12 yrs)
- Spanish Tempranillo
Tempranillo is a variety of black grape widely grown to make full-bodied red wines in its native Spain. It is the main grape used in Rioja, and is often referred to as Spain's "noble grape". Its name is the diminutive of the Spanish temprano , a reference to the fact that it ripens several weeks...
(2–8 yrs)
- Greek Xynomavro
Xynomavro or Xinomavro is the principal red wine grape of the uplands of the Naoussa and Amyntaion areas, in the prefecture of Imathia in Northern Greece. Various writers have compared Xynomavro to Bordeaux, Burgundy, Barolo, etc....
(4–10 yrs)
Factors and influences
The ratio of
sugarSugar is a class of edible crystalline substances, mainly sucrose, lactose, and fructose. Human taste buds interpret its flavor as sweet. Sugar as a basic food carbohydrate primarily comes from sugar cane and from sugar beet, but also appears in fruit, honey, sorghum, sugar maple , and in many...
s,
acidAn acid is traditionally considered any chemical compound that, when dissolved in water, gives a solution with a hydrogen ion activity greater than in pure water, i.e. a pH less than 7.0...
s and phenolics to
waterWater is an ubiquitous chemical substance that is composed of hydrogen and oxygen and is essential for all known forms of life.In typical usage, water refers only to its liquid form or state, but the substance also has a solid state, ice, and a gaseous state, water vapor or steam. Water covers 71%...
is a key determination of how well a wine can age. The less water in the grapes prior to
harvestThe harvesting of wine grapes is one of the most crucial steps in the process of winemaking. The time of harvest is determined primarily by the ripeness of the grape as measured by sugar, acid and tannin levels with winemakers basing their decision to pick based on the style of wine they wish to...
, the more likely the resulting wine will have some aging potential. Grape variety, climate, vintage and viticultural practice come into play here. Grape varieties with thicker skins, from a dry growing season where little
irrigationIrrigation is an artificial application of water to the soil. It is usually used to assist in growing crops in dry areas and during periods of inadequate rainfall...
was used and yields were kept low will have less water and a higher ratio of sugar, acids and phenolics. The process of making Eisweins, where water is removed from the grape during pressing as frozen ice crystals, has a similar effect of decreasing the amount of water and increasing aging potential.
In winemaking, the duration of
macerationMaceration is the winemaking process where the phenolic materials of the grape— tannins, coloring agents and flavor compounds— are leached from the grape skins, seeds and stems into the must. The term is usually used in reference to wine, but is sometimes used with other drinks, such as...
or skin contact will influence how much phenolic compounds are leached from skins into the wine. Pigmented tannins,
anthocyaninAnthocyanins are water-soluble vacuolar pigments that may appear red, purple, or blue according to pH. They belong to a parent class of molecules called flavonoids synthesized via the phenylpropanoid pathway; they are odorless and nearly flavorless, contributing to taste as a moderately stringent...
s,
colloidA colloid is a type of chemical mixture in which one substance is dispersed evenly throughout another.The particles of the dispersed substance are only suspended in the mixture, unlike in a solution, in which they are completely dissolved...
s, tannin-polysaccharides and tannin-
proteinProteins are organic compounds made of amino acids arranged in a linear chain and folded into a globular form. The amino acids in a polymer chain are joined together by the peptide bonds between the carboxyl and amino groups of adjacent amino acid residues...
s not only influence a wine's resulting color but also act as preservatives. During fermentation adjustment to a wine's acid levels can be made with wines with lower pH having more aging potential. Exposure to oak either during fermentation or after during barrel aging will introduce more phenolic compounds to the wines. Prior to bottling, excessive fining or filtering of the wine could strip the wine of some phenolic solids and may lessen a wine's ability to age.
The storage condition of the bottled wine will influence a wine's aging. Vibrations and heat fluctuations can hasten a wine's deterioration and cause adverse effect on the wines. In general, a wine has a greater potential to develop complexity and more aromatic bouquet if it is allowed to age slowly in a relatively cool environment. The lower the temperature, the more slowly a wine develops. On average, the rate of chemical reactions in wine double with each 18
°FFahrenheit is the temperature scale proposed in 1724 by, and named after, the physicist Daniel Gabriel Fahrenheit . Today, the scale has been replaced by the Celsius scale in most countries; it is still in use for non-scientific purposes in the United States and a few other nations, such as...
(8
°CCelsius is a temperature scale that is named after the Swedish astronomer Anders Celsius , who developed a similar temperature scale two years before his death...
) increase in temperature. Wine expert Karen MacNeil, recommends keeping wine intended for aging in a cool area with a constant temperature around 55°F (13°C). Wine can be stored at temperatures as high as 69°F (20°C) without long term negative effect. Professor Cornelius Ough of the
University of California, DavisThe University of California, Davis is a public research university located in Davis, California, and one of ten campuses in the University of California system. Commonly referred to as UC Davis, the school was originally established in 1905 as the University Farm, an extension of UC Berkeley. UC...
believes that wine could be exposed to temperatures as high as 120°F (49°C) for a few hours and not be damaged. However, most experts believe that extreme temperature fluctuations (such as repeated transferring a wine from a warm room to a cool refrigerator) would be detrimental to the wine. The ultra-violet rays of direct sunlight should also be avoided because of the free radicals that can develop in the wine and result in oxidation.
Wines packaged in large format bottles, such as magnums and 3
liter
Jeroboams, seem to age more slowly than wines packaged in regular 750 ml bottles or half bottles. This may be because of the greater proportion of oxygen exposed to the wine during the bottle process. The advent of
alternative wine closuresAlternative wine closures are substitute closures used in the wine industry for sealing wine bottles in place of traditional cork closures. The emergence of these alternatives has grown in response to quality control efforts by winemakers to protect against "cork taint" caused by the presence of...
to cork, such as screw caps and synthetic corks have opened up recent discussions on the aging potential of wines sealed with these alternative closures. Currently there is no conclusive results and the topic is the subject of ongoing research.
Bottle sickness
One of the short-term aging needs of wine is a period where the wine is considered "sick" due to the trauma and volatility of the bottling experience. During bottling some oxygen is exposed to the wine, causing a domino effect of chemical reaction with various components of the wine. The time it takes for the wine to settle down and have the oxygen fully dissolve and integrate with the wine is considered its period of "bottle shock". During this time the wine could taste drastically different than it did prior to bottling or how it will taste after the wine has settled. While many modern bottling lines try to treat the wine as gently as possible and utilize
inert gasAn inert gas is any gas that is not reactive with elements.Unlike noble gases, inert gas is not necessarily elemental and is often a compound gas. Like the noble gases the tendency for non-reactivity is due to the valence, the outermost electron shell, being complete in all the inert gases...
es to minimize the amount of oxygen exposure, all wine goes through some period of bottle shock. The length of this period will vary with each individual wine.
Dumb phase
During the course of aging a wine may slip into a "dumb phase" where its aromas and flavors are very muted. In Bordeaux this phase is called the
age ingrat or "difficult age" and is likened to a teenager going through
adolescenceAdolescence Adolescence Adolescence (lat adolescere, (to grow) is a transitional stage of physical and mental human development that occurs between childhood and adulthood. This transition involves biological (i.e. pubertal), social, and psychological changes, though the biological or...
. The cause or length of time that this "dumb phase" will last is not yet fully understood and seems to vary from bottle to bottle.
Effects on wine
As red wine ages, the harsh tannins of its youth gradually give way to a softer
mouthfeelMouthfeel is a product's physical and chemical interaction in the mouth, an aspect of food rheology. It is a concept used in many areas related to the testing and evaluating of foodstuffs, such as wine-tasting and rheology. It is evaluated from initial perception on the palate, to first bite,...
. An inky dark color will eventually fade to a light brick red. These changes occur due to the complex chemical reactions of the phenolic compounds of the wine. In processes that begin during fermentation and continue after bottle, these compounds bind together and aggregate. Eventually these particles reach a certain size where they are too large to stay suspended in the solution and the precipitate out. The presence of visible sediment in a bottle will usually indicate a mature wine. The resulting wine, with this loss of tannins and pigment, will have a paler color and taste softer, less astringent. The sediment, while harmless, can have an unpleasant taste and is often separated from the wine by decanting.
During the aging process, the perception of a wine's acidity may change even though the total measurable amount of acidity is more or less constant throughout a wine's life. This is due to the
esterificationEsterification is the general name for a chemical reaction in which two reactants form an ester as the reaction product. Esters are common in organic chemistry and biological materials, and often have a characteristic pleasant, fruity odor. This leads to their extensive use in the fragrance and...
of the acids, combining with alcohols in complex array to form
esterEsters are chemical compounds derived by reacting an oxoacid with a hydroxyl compound such as an alcohol or phenol. Esters are usually derived from an inorganic acid or organic acid in which at least one -OH group is replaced by an -O-alkyl group, and most commonly from carboxylic acids and...
s. In addition to making a wine taste less acidic, these esters introduce a range of possible aromas. Eventually the wine may age to a point where other components of the wine (such as a tannins and fruit) are less noticeable themselves, which will then bring back a heightened perception of wine acidity. Other chemical processes that occur during aging include the
hydrolysisHydrolysis is a chemical reaction during which one or more water molecules are split into hydrogen and hydroxide ions, which may go on to participate in further reactions. It is the type of reaction that is used to break down certain polymers, especially those made by step-growth polymerization...
of flavor precursors which detach themselves from
glucoseGlucose , a monosaccharide also known as - grape sugar, blood sugar, or corn sugar, is a very important carbohydrate in biology. The living cell uses it as a source of energy and metabolic intermediate...
molecules and introduce new flavor notes in the older wine and Aldehydes become oxidized. The interaction of certain phenolics develop what is known as
tertiaryThe Tertiary is a term for a geologic period 65 million to 2.588 million years ago. The Tertiary covered the time span between the superseded Secondary period and the Quaternary...
aromas which are different from the primary aromas that are derived from the grape and during fermentation.
As a wine starts to mature, its bouquet will become more developed and multi-layered. While a taster may be able to pick out a few fruit notes in a young wine, a more complex wine will have several distinct fruit, floral, earthy, mineral and oak derived notes. The lingering finish of a wine will lengthen. Eventually the wine will reach a point of maturity, when it is said to be at its "peak". This is the point when the wine has the maximum amount of complexity, most pleasing mouthfeel and softening of tannins and has not yet started to decay. When this point will occur is not yet predictable and can vary from bottle to bottle. If a wine is aged for too long, it will start to descend into decrepitude where the fruit tastes hollow and weak while the wine's acidity becomes dominant.
Artificial aging
There is a long history of man using artificial means to try to accelerate the natural aging process. In
Ancient RomeAncient Rome was a civilization that grew out of a small agricultural community founded on the Italian Peninsula as early as the 10th century BC. Located along the Mediterranean Sea, it became one of the largest empires in the ancient world....
a smoke chamber known as a
fumariumA Fumarium was a smoke chamber used in Ancient Rome to enhance the flavor of wine through artificially "aging" the wine. Amphorae were placed in the chamber, which was built on top of a heated hearth, in order to impart a smoky flavor in the wine that also seemed to sharpen the acidity. The wine...
was used to enhance the flavor of wine through artificial aging.
AmphoraAn amphora is a type of ceramic vase with two handles and a long neck narrower than the body. The word amphora is Latin, derived from the Greek amphoreus , an abbreviation of amphiphoreus , a compound word combining amphi- plus phoreus , from pherein , referring to...
e were placed in the chamber, which was built on top of a heated
hearthIn common historic and modern usage, a hearth is a brick- or stone-lined fireplace or oven used for cooking and/or heating. Because of its nature, in historic times the hearth was considered an integral part of a home, often its central or most important feature: its Latin name is focus...
, in order to impart a smoky flavor in the wine that also seemed to sharpen the acidity. The wine would sometimes come out of the fumarium with a paler color just like aged wine. Modern winemaking techniques like micro-oxygenation can have the side effect of artificially aging the wine. In the production of Madeira and rancio wines, the wines are deliberately exposed to excessive temperatures to accelerate the maturation of the wine. Other techniques used to artificially age wine (with inconclusive results on their effectiveness) include shaking the wine, exposing it to
radiationIn physics, radiation describes any process in which energy emitted by one body travels through a medium or through space, ultimately to be absorbed by another body...
,
magnetismIn physics, the term magnetism is used to describe how materials respond on the microscopic level to an applied magnetic field; to categorize the magnetic phase of a material. For example, the most well known form of magnetism is ferromagnetism such that some ferromagnetic materials produce their...
or ultra-sonic waves. More recently, experiments with artificial aging through high-voltage electricity have produced results above the remaining techniques, as assessed by a panel of wine tasters.