Ancient Times: Aged Wines and Connoisseurship As I write, the earliest evidence we have for wine made from grapes, residues at the bottom of a pot found in western Iran, dates from around 6000 As I write, the earliest evidence we have for wine made from grapes, residues at the bottom of a pot found in western Iran, dates from around 6000 BCE BCE. From 3000 BCE BCE on, wine was a prominent part of trade in western Asia and Egypt. Wild grapes and the first wines were red, but the Egyptians had a color mutant of the grape plant and made white wines from it. They would ferment grape juice in large clay jars. The contents of the jars were eventually sampled and graded, and the jars marked, stoppered, and sealed with mud. The airtight containers allowed wine to be aged for years. Many wine amphoras found in the tombs of the pharaohs carry labels with the date of production, the region in which the wine was made, sometimes a brief description and the name of the winemaker. Wine connoisseurship is ancient! on, wine was a prominent part of trade in western Asia and Egypt. Wild grapes and the first wines were red, but the Egyptians had a color mutant of the grape plant and made white wines from it. They would ferment grape juice in large clay jars. The contents of the jars were eventually sampled and graded, and the jars marked, stoppered, and sealed with mud. The airtight containers allowed wine to be aged for years. Many wine amphoras found in the tombs of the pharaohs carry labels with the date of production, the region in which the wine was made, sometimes a brief description and the name of the winemaker. Wine connoisseurship is ancient!

Greece and Rome Phoenician and Greek traders introduced the cultivated vine throughout the Mediterranean basin, where the Greeks developed the cult of Dionysos, G.o.d of vegetation, the vine, and the temporary release from ordinary life that wine made possible. By Homer's time, about 700 Phoenician and Greek traders introduced the cultivated vine throughout the Mediterranean basin, where the Greeks developed the cult of Dionysos, G.o.d of vegetation, the vine, and the temporary release from ordinary life that wine made possible. By Homer's time, about 700 BCE BCE, wine had become a standard beverage in Greece, one that was made strong, watered down before drinking, and graded in quality for freeman and slave. The culture of the vine was not established in Italy until about 200 BCE BCE, but it took hold so well that the Greeks took to calling southern Italy Oenotria, Oenotria, "land of the grape." "land of the grape."

Over the next couple of centuries, Rome advanced the art of winemaking considerably. Pliny devoted a full book of his Natural History Natural History to the grape. He noted that there were now an infinite number of varieties, that the same grape could produce very different wines in different places, and named Italy, Greece, Egypt, and Gaul (France) as admired sources. Like the Egyptians, the Romans had airtight amphoras that allowed them to age wine for years without spoiling. The Greeks and Romans also preserved and flavored wines with tree resins or the pitch refined from them, salt, and spices. to the grape. He noted that there were now an infinite number of varieties, that the same grape could produce very different wines in different places, and named Italy, Greece, Egypt, and Gaul (France) as admired sources. Like the Egyptians, the Romans had airtight amphoras that allowed them to age wine for years without spoiling. The Greeks and Romans also preserved and flavored wines with tree resins or the pitch refined from them, salt, and spices.

It was in Roman times that wooden casks - an innovation of northern Europe - arrived along the Mediterranean as an alternative to clay amphoras. During subsequent centuries, they became the standard wine vessel, and amphoras disappeared. Casks had the advantage of being lighter and less fragile, but the disadvantage of not being airtight. This meant that wines could only be stored in them for a handful of years before they became overoxidized and unpleasant to drink. Excellent aged wines therefore disappeared along with the amphora, and only reappeared after more than a thousand years with the invention of the cork-stoppered bottle (p. 724).

The Spread of Winemaking in Europe; the Rise of France After the fall of Rome around the 5th century After the fall of Rome around the 5th century CE CE, Christian monasteries advanced the arts of viticulture and winemaking in Europe. Local rulers endowed them with tracts of land, which they then cleared of forest and reclaimed from swamps, bringing systematic, organized agriculture to spa.r.s.ely settled regions, and the grape to northern France and Germany. Wine was required for the sacrament of Communion, and it and beer were made for daily consumption, to serve guests, and to sell. It was in the Middle Ages that the wines of Burgundy became famous.

From the late Middle Ages on, France slowly became the preeminent source of wine in Europe. By the 1600s the wines of France, and especially Bordeaux, which had the advantage being a port, were important exports to England and Holland. Meanwhile Italy fell behind, a victim of political and economic circ.u.mstance. Until the middle of the 19th century it was not a nation but a collection of city-states, each with protective tariffs and little of the international trade that brought compet.i.tion and improvement to the wine regions of France. Most of the wine was consumed locally, and the grapevines grown not in vineyards but in sharecroppers' plots, between rows of food plants or trained on trees.

Food Words: Wine, Vine, Grape Wine, Vine, GrapeOur language bears witness to the fact that from the very earliest times, people thought of the grapevine not as the source of edible fruit, but as the source of wine. Our words vine vine and and wine wine come from the same root word, and that word meant the fermented juice of the vine's fruit. This root is so ancient that it predates the divergence of Indo-European from other prehistoric languages of western Asia. The words for the fruit itself, on the other hand, are different in different languages. The English word come from the same root word, and that word meant the fermented juice of the vine's fruit. This root is so ancient that it predates the divergence of Indo-European from other prehistoric languages of western Asia. The words for the fruit itself, on the other hand, are different in different languages. The English word grape grape appears to come from an Indo-European root meaning "curved" or "crooked," probably referring to the curved blade of the knife used to harvest grape bunches, or to the shape of the bunch stem. appears to come from an Indo-European root meaning "curved" or "crooked," probably referring to the curved blade of the knife used to harvest grape bunches, or to the shape of the bunch stem. Grapple Grapple and and crumpet crumpet are related words. are related words.

New Wines and New Containers Early modern times brought the invention of several wonderful variants on plain fermented grape juice, and important improvements in wine storage. Sometime before 1600, Spanish winemakers found that they could both stabilize and give a new character to wines by fortifying them with brandy; the result was sherry. Around 1650, Hungarian winemakers managed to make deliciously concentrated and very sweet Tokaji wine from grapes infected by an otherwise destructive fungus, which came to be known as the "n.o.ble rot." This was the forerunner of French Sauternes and similar sweet German wines. At about the same time, English importers of white wine from the Champagne region east of Paris discovered that they could make the wine delightfully bubbly by transferring it from barrel to bottles before it had finished fermenting. And a few decades later, the English developed port in the effort to stabilize strong red wines during their sea journey from Portugal. The shippers added distilled alcohol to the wines to prevent spoilage, and thus discovered the pleasures of fortified sweet red wines. Early modern times brought the invention of several wonderful variants on plain fermented grape juice, and important improvements in wine storage. Sometime before 1600, Spanish winemakers found that they could both stabilize and give a new character to wines by fortifying them with brandy; the result was sherry. Around 1650, Hungarian winemakers managed to make deliciously concentrated and very sweet Tokaji wine from grapes infected by an otherwise destructive fungus, which came to be known as the "n.o.ble rot." This was the forerunner of French Sauternes and similar sweet German wines. At about the same time, English importers of white wine from the Champagne region east of Paris discovered that they could make the wine delightfully bubbly by transferring it from barrel to bottles before it had finished fermenting. And a few decades later, the English developed port in the effort to stabilize strong red wines during their sea journey from Portugal. The shippers added distilled alcohol to the wines to prevent spoilage, and thus discovered the pleasures of fortified sweet red wines.

Bottles and Corks The 17th and 18th centuries brought two major innovations that once again made it possible to age wines for many years, a possibility that had disappeared when the impermeable amphora was replaced by wood barrels. These momentous developments were slim bottles and cork stoppers! The English discovery of sparkling Champagne depended on the fact that they had begun plugging bottle necks with compressible gas-tight cork instead of cloth, and that they had especially strong bottles that could withstand the inner pressure (the gla.s.s strength came from manufacturing with hot coal fires rather than wood fires). And during the 18th century, the wine bottle gradually evolved from a short, stout flask to the familiar elongated bottle. The bulky bottles were only used to convey the wine from barrel to table or to hold it for a day or two. When bottles had slimmed down enough that they could lie on their sides, their contents wetting the cork and preventing it from shrinking and admitting air, then wine could be stored in them for many years without spoiling, and sometimes with great improvements in flavor. The 17th and 18th centuries brought two major innovations that once again made it possible to age wines for many years, a possibility that had disappeared when the impermeable amphora was replaced by wood barrels. These momentous developments were slim bottles and cork stoppers! The English discovery of sparkling Champagne depended on the fact that they had begun plugging bottle necks with compressible gas-tight cork instead of cloth, and that they had especially strong bottles that could withstand the inner pressure (the gla.s.s strength came from manufacturing with hot coal fires rather than wood fires). And during the 18th century, the wine bottle gradually evolved from a short, stout flask to the familiar elongated bottle. The bulky bottles were only used to convey the wine from barrel to table or to hold it for a day or two. When bottles had slimmed down enough that they could lie on their sides, their contents wetting the cork and preventing it from shrinking and admitting air, then wine could be stored in them for many years without spoiling, and sometimes with great improvements in flavor.

Pasteur and the Beginnings of a Scientific Understanding of Wine In 1863 the French Emperor Louis Napoleon asked the great chemist Louis Pasteur to study the "maladies" of wine. Three years later, Pasteur published the landmark In 1863 the French Emperor Louis Napoleon asked the great chemist Louis Pasteur to study the "maladies" of wine. Three years later, Pasteur published the landmark Etudes sur le vin. Etudes sur le vin. Pasteur and others had already demonstrated that yeast is a living ma.s.s of microbes, and thus had made it possible to begin to identify and control the kinds of microbes that both make wine and spoil it. But Pasteur was the first to a.n.a.lyze the development of wine, to discover the central role of oxygen, and show why both barrel and bottle were indispensable for making good wine, the barrel for providing oxygen to the young wine to help mature it, and the bottle for excluding oxygen from the mature wine to help preserve it. Pasteur and others had already demonstrated that yeast is a living ma.s.s of microbes, and thus had made it possible to begin to identify and control the kinds of microbes that both make wine and spoil it. But Pasteur was the first to a.n.a.lyze the development of wine, to discover the central role of oxygen, and show why both barrel and bottle were indispensable for making good wine, the barrel for providing oxygen to the young wine to help mature it, and the bottle for excluding oxygen from the mature wine to help preserve it.

In my view, it is oxygen which makes makes wine; it is by its influence that wine ages; it is oxygen which modifies the harsh principles of new wine and makes the bad taste disappear... wine; it is by its influence that wine ages; it is oxygen which modifies the harsh principles of new wine and makes the bad taste disappear...It is necessary to aerate the wine slowly to age it, but the oxidation must not be pushed too far. It weakens the wine too much, wears it out, and removes from red wine nearly all its color. There exists a period...during which the wine must pa.s.s from a permeable container [the barrel] to one nearly impermeable [the bottle].

Scientific Approaches to Making Wine Pasteur planted the seed of a scientific approach to winemaking. That seed soon took root in both France and the United States. In the 1880s, the University of Bordeaux and the University of California established inst.i.tutes of oenology. The Bordeaux group focused on understanding and improving traditional French methods for producing fine wines, and discovered the nature of the malolactic fermentation (p. 730). The California inst.i.tute moved from Berkeley to Davis in 1928, and studied how best to build a wine industry in the absence of a local tradition, including determining what grape varieties were best suited to various climatic conditions. Today, thanks to this and similar work in a number of countries, and to the general modernization of winemaking, more good wine is being made in more parts of the world than ever before. Pasteur planted the seed of a scientific approach to winemaking. That seed soon took root in both France and the United States. In the 1880s, the University of Bordeaux and the University of California established inst.i.tutes of oenology. The Bordeaux group focused on understanding and improving traditional French methods for producing fine wines, and discovered the nature of the malolactic fermentation (p. 730). The California inst.i.tute moved from Berkeley to Davis in 1928, and studied how best to build a wine industry in the absence of a local tradition, including determining what grape varieties were best suited to various climatic conditions. Today, thanks to this and similar work in a number of countries, and to the general modernization of winemaking, more good wine is being made in more parts of the world than ever before.

Traditional and Industrial Wines There's now a spectrum of approaches among winemakers, and so a spectrum of wines from which we can choose. At one end is the relatively straightforward approach found in traditional winemaking regions: the grapes are grown in a place and with methods that maximize wine quality; they're simply crushed, fermented, the new wine matured for some time, and bottled. At the other end of the spectrum are advanced manufacturing processes that treat grapes and wine like other industrial materials. These aim to approximate the qualities of the traditionally produced wine by nontraditional means that are less labor intensive and less expensive. The grapes themselves need not be coaxed to an ideal ripeness because the winemaker can use various separation technologies to adjust their content of water, sugar, acid, alcohol, and other components. The effects of barrel and bottle aging can be simulated inexpensively and rapidly by means of oak chips or sawdust, and the bubbling of pure oxygen through wine stored in huge steel tanks. There's now a spectrum of approaches among winemakers, and so a spectrum of wines from which we can choose. At one end is the relatively straightforward approach found in traditional winemaking regions: the grapes are grown in a place and with methods that maximize wine quality; they're simply crushed, fermented, the new wine matured for some time, and bottled. At the other end of the spectrum are advanced manufacturing processes that treat grapes and wine like other industrial materials. These aim to approximate the qualities of the traditionally produced wine by nontraditional means that are less labor intensive and less expensive. The grapes themselves need not be coaxed to an ideal ripeness because the winemaker can use various separation technologies to adjust their content of water, sugar, acid, alcohol, and other components. The effects of barrel and bottle aging can be simulated inexpensively and rapidly by means of oak chips or sawdust, and the bubbling of pure oxygen through wine stored in huge steel tanks.

Industrial wines are marvels of reverse engineering, and often taste good, clean, and without obvious faults. Wine made on a small scale with minimal manipulation is less predictable in its quality, but this is because it is more distinctive, an expression of grapes that were grown in a particular place and year, and transformed by a particular winemaker. Such wine is more expensive than industrial wine, sometimes much better, and usually more interesting.

Wine Grapes Grapes provide the substance of wine, and therefore determine many of its qualities. Their most important components are Sugars, which the yeasts feed on and convert into alcohol. Wine grapes are generally harvested with 2030% sugar, mainly glucose and fructose.

Acids, mainly tartaric and some malic, which help prevent the growth of undesirable microbes during fermentation, and are a major component of wine flavor.

Tannins and related phenolic compounds, which contribute an astringent feeling and thereby a body and weightiness to wine (p. 737).

Pigment molecules that provide color, and sometimes contribute to astringency as well. Red grapes contain anthocyanin pigments (p. 267), mainly in the skins. "White" grapes lack anthocyanins; their yellowish color comes from a different group of phenolic compounds, the flavonols.

Aroma compounds, which may be generically grapey, or distinctive of a particular grape variety. Many aromatics are chemically bound to other molecules, often sugars, and so aren't evident in the raw fruit; during winemaking, fruit and yeast enzymes liberate the aromatics and so make them available for us to enjoy.

Grape Varieties and Clones The grapevine evolved with the ability to regenerate itself and grow vigorously in the spring. It's easily propagated by cuttings, and readily lends itself to creating identical versions, or The grapevine evolved with the ability to regenerate itself and grow vigorously in the spring. It's easily propagated by cuttings, and readily lends itself to creating identical versions, or clones clones of a given plant. And it's a variable species, one that offers many differences in growth habit, requirements for water and temperature, and fruit composition. For several millennia, and until around 1800, grapes were mostly cultivated and made into wine throughout western Asia and Europe by small groups of people essentially isolated from each other and living in different environments. So there developed a large number of distinctive grape varieties, each selected by particular people for characteristics they found desirable. of a given plant. And it's a variable species, one that offers many differences in growth habit, requirements for water and temperature, and fruit composition. For several millennia, and until around 1800, grapes were mostly cultivated and made into wine throughout western Asia and Europe by small groups of people essentially isolated from each other and living in different environments. So there developed a large number of distinctive grape varieties, each selected by particular people for characteristics they found desirable.

Today it's estimated that there are around 15,000 different varieties of the Eurasian grape, Vitis vinifera. Vitis vinifera. A single variety - Pinot Noir, for example, or Cabernet Sauvignon - may exist in the form of several hundred different clones, each a somewhat different version of that variety. Some varieties have very distinctive aromas; others are more subtle or even anonymous and therefore allow the aromas of the fermentation and aging more prominence. The term A single variety - Pinot Noir, for example, or Cabernet Sauvignon - may exist in the form of several hundred different clones, each a somewhat different version of that variety. Some varieties have very distinctive aromas; others are more subtle or even anonymous and therefore allow the aromas of the fermentation and aging more prominence. The term n.o.ble n.o.ble is applied to varieties that produce wines with the potential for developing great complexity over many years in the bottle; these include the French Cabernet Sauvignon, Pinot Noir, and Chardonnay, the Italian Nebbiolo and Sangiovese, and the German Riesling. is applied to varieties that produce wines with the potential for developing great complexity over many years in the bottle; these include the French Cabernet Sauvignon, Pinot Noir, and Chardonnay, the Italian Nebbiolo and Sangiovese, and the German Riesling.

The Influence of Growing Conditions; Vintage and "Terroir"

Pampered Vines Don't Make the Best Wines As Pliny observed 2,000 years ago, "the same vine has a different value in different places." The quality of grapes, and of the wine made from them, is influenced by the conditions in which the grapes grow and mature. To produce a decent wine, the grapes must ripen to an adequate sweetness, and so the vine must get enough sun, warmth, minerals, and water. On the other hand, abundant water produces watery fruit, abundant soil nitrogen produces excess foliage that shades the fruit and gives it odd flavors, and abundant sun and warmth produce fruit with plenty of sugar but reduced acidity and aroma compounds, and thus a strong but flat wine. As Pliny observed 2,000 years ago, "the same vine has a different value in different places." The quality of grapes, and of the wine made from them, is influenced by the conditions in which the grapes grow and mature. To produce a decent wine, the grapes must ripen to an adequate sweetness, and so the vine must get enough sun, warmth, minerals, and water. On the other hand, abundant water produces watery fruit, abundant soil nitrogen produces excess foliage that shades the fruit and gives it odd flavors, and abundant sun and warmth produce fruit with plenty of sugar but reduced acidity and aroma compounds, and thus a strong but flat wine.

Vintage Wines The grapes that make the best wines seem to be produced in a narrow range of conditions - barely adequate water, minerals and light and heat - that encourage complete but slow, gradual ripening. Those conditions may or may not be realized in a given year. Hence the significance for many wines of the The grapes that make the best wines seem to be produced in a narrow range of conditions - barely adequate water, minerals and light and heat - that encourage complete but slow, gradual ripening. Those conditions may or may not be realized in a given year. Hence the significance for many wines of the vintage, vintage, the particular year in which the grapes are grown and harvested. Some years yield better wines than others. the particular year in which the grapes are grown and harvested. Some years yield better wines than others.

Hybrid and American Wine GrapesThe Eurasian wine grape Vitis vinifera Vitis vinifera has a number of sister species in North America with which it can breed, and over the centuries plant breeders have produced a number of different Euro-American hybrids. These were generally denigrated by European connoisseurs and bureaucrats for their untypical flavors, but the better of them, and American varieties themselves, are coming to be appreciated for their own qualities. They include grapes based on the mainly northeastern has a number of sister species in North America with which it can breed, and over the centuries plant breeders have produced a number of different Euro-American hybrids. These were generally denigrated by European connoisseurs and bureaucrats for their untypical flavors, but the better of them, and American varieties themselves, are coming to be appreciated for their own qualities. They include grapes based on the mainly northeastern Vitis labrusca Vitis labrusca (Concord, floral Catawba, strawberry-like Ives), midwestern (Concord, floral Catawba, strawberry-like Ives), midwestern Vitis aestivalis Vitis aestivalis (Norton, Cynthiana), southeastern (Norton, Cynthiana), southeastern Vitis rotundifolia Vitis rotundifolia (floral-citrus Scuppernong), and on complex parentage (Chambourcin, developed in the Loire region of France). (floral-citrus Scuppernong), and on complex parentage (Chambourcin, developed in the Loire region of France).

Terroir In recent times, much has been said and written about the importance in winemaking of In recent times, much has been said and written about the importance in winemaking of terroir terroir: the influence on a wine of the particular place in which the grapes were grown. The French word includes the entire physical environment of the vineyard: the soil, its structure and mineral content; the water held in the soil; the vineyard's elevation, slope, and orientation; and the microclimate, the regime of temperature, sunlight, humidity, and rainfall. Each of these aspects can vary over small distances, from one vineyard to the next; and each can affect the growth of the vine and the development of its fruit, sometimes in indirect ways. For example, sloping ground and certain kinds of soil encourage water to drain away from the roots, and absorb and release the sun's heat to the vine in different ways. A south-facing slope can increase the exposure to autumn sunlight by 50% over a planting on level ground, and thus extend the growing season and acc.u.mulation of flavor compounds.

The wine connoisseur enjoys detecting and marveling at the expression of terroir terroir in wines, the palpable differences in the wines made from neighboring vineyards. The winemaker, on the other hand, generally tries to manage and minimize the effects of less than ideal in wines, the palpable differences in the wines made from neighboring vineyards. The winemaker, on the other hand, generally tries to manage and minimize the effects of less than ideal terroirs terroirs and vintages. There's nothing new about this effort to make the best of things. The French have been adding sugar to their fermenting grapes for centuries to compensate for incomplete ripening. What's new nowadays is the degree to which the grape composition can be manipulated after harvest, so that the wine becomes less the product of a particular place and year, and more the product of modern fermentation technology. and vintages. There's nothing new about this effort to make the best of things. The French have been adding sugar to their fermenting grapes for centuries to compensate for incomplete ripening. What's new nowadays is the degree to which the grape composition can be manipulated after harvest, so that the wine becomes less the product of a particular place and year, and more the product of modern fermentation technology.

Making Wine The making of a basic table wine can be divided into three stages. In the first, the ripe grapes are crushed to free their juice. In the second, the grape juice is fermented by sugar-consuming, alcohol-producing yeasts into new wine. The third stage is the aging or maturing of the new wine. This is a period during which the chemical const.i.tuents of the grape and the products of fermentation react with each other and with oxygen to form a relatively stable ensemble of flavor molecules.

Crushing Grapes to Make the Must Crushing extracts from the grape the liquid that will become wine. This step therefore determines to a large extent the final wine's composition and potential qualities. Crushing extracts from the grape the liquid that will become wine. This step therefore determines to a large extent the final wine's composition and potential qualities.

The substances important to wine quality are not evenly distributed in the grape. The stems contain bitter-tasting resins and are usually separated from the grapes as they are crushed. The skin holds much of the fruit's phenolic compounds, both pigments and tannins, as well as most of the acid and the many compounds that give the grape its characteristic aroma. Like the stem, the seeds at the center are full of tannins, oils, and resins, and care is taken not to break them open during the pressing.

As a ma.s.s of grapes is crushed in a mechanical press, the first juice to come out, the free run, free run, is primarily from the middle of the pulp, and is the clearest, purest essence of the grape, sweet and largely tannin free. As mechanical pressure is applied, juices from just under the skin and around the seeds augment the free run with a more complex character. The extent of pressing will have an important influence on the character of the final wine. The liquid portion, called the is primarily from the middle of the pulp, and is the clearest, purest essence of the grape, sweet and largely tannin free. As mechanical pressure is applied, juices from just under the skin and around the seeds augment the free run with a more complex character. The extent of pressing will have an important influence on the character of the final wine. The liquid portion, called the must, must, is 70 to 85% water, 12 to 27% sugars, mainly glucose and fructose, and about 1% acids. is 70 to 85% water, 12 to 27% sugars, mainly glucose and fructose, and about 1% acids.

Fruits of the grape vine, Vitis vinifera. Vitis vinifera. The different regions of the grape contain different proportions of sugar, acid, and other flavor components. The different regions of the grape contain different proportions of sugar, acid, and other flavor components.

Making Wine After the Crush In the case of white wines, the must is left in contact with the skins for a few hours and removed with gentle pressure before fermentation. It thus picks up little tannic material or pigmentation. Rose musts and red wine musts are partly fermented in contact with the red skins. The longer the must is in contact with skin and seeds, and the harder it is pressed, the deeper the color (whether yellow or red) and the more astringent the taste. In the case of white wines, the must is left in contact with the skins for a few hours and removed with gentle pressure before fermentation. It thus picks up little tannic material or pigmentation. Rose musts and red wine musts are partly fermented in contact with the red skins. The longer the must is in contact with skin and seeds, and the harder it is pressed, the deeper the color (whether yellow or red) and the more astringent the taste.

Before beginning the fermentation, the winemaker usually adds two substances to the must. One, sulfur dioxide, suppresses the growth of undesirable wild yeasts and bacteria, and prevents the oxidation of both flavor and pigment molecules (the same treatment is given to many dried fruits, and for the same reason). Though this treatment may sound antiseptically modern, it is centuries old. One of the natural by-products of fermentation that is increased by sulfuring is sulfites, sulfur compounds that can induce an allergic reaction in sensitive people.

The second additive is either sugar or acid, and it is used to correct the balance between these two substances. Grapes that ripen in a cool climate can lack the sugar to produce enough alcohol for a stable wine; grapes that ripen in a hot climate metabolize some of their acids and can produce a flat-tasting wine. French winemakers usually add sugar; California winemakers often add tartaric acid.

The Alcoholic Fermentation The Fermentation Yeasts Fermentation can begin with or without the addition of a starter culture of yeast. The winemaker can choose among many different strains of Fermentation can begin with or without the addition of a starter culture of yeast. The winemaker can choose among many different strains of Saccharomyces, Saccharomyces, or allow the fermentation to begin spontaneously with "wild" yeasts from the grape skins (species of or allow the fermentation to begin spontaneously with "wild" yeasts from the grape skins (species of Kloeckera, Candida, Pichia, Hansenula, Kloeckera, Candida, Pichia, Hansenula, and others). These are always eventually displaced by and others). These are always eventually displaced by Saccharomyces cerevisiae, Saccharomyces cerevisiae, which has a greater tolerance for alcohol, but they do contribute flavor compounds to the finished wine. which has a greater tolerance for alcohol, but they do contribute flavor compounds to the finished wine.

The primary job of the yeast is to convert sugar to alcohol, but it also produces various volatile, aromatic molecules that the grape itself cannot supply. Prominent among them are the longer-chain alcohols, and esters, a cla.s.s of compounds that combine an acid with an alcohol or phenol. Both yeast and grape enzymes and the acid conditions also liberate aromatic molecules from the nonvolatile sugar complexes in which some are stored in the grape, so fermentation also brings out the grape's own flavor potential.

Temperatures and Times The winemaker varies the conditions of fermentation according to the particular kind of wine being made. In the case of delicate white wines, the must is fermented for four to six weeks at about 60F/16C. With more robust red wines, the must is fermented at a temperature between 65 and 80F/1827C in contact with the skins, to extract pigments, tannins, and flavor. This phase may last for 4 to 14 days (less if heat or a carbon dioxide treatment is applied). Then the must is separated from the skins and fermented again for a total of two to three weeks. One of the most critical variables during fermentation is temperature. The lower the temperature, the slower and longer the fermentation, and the more aromatic molecules acc.u.mulate. The winemaker varies the conditions of fermentation according to the particular kind of wine being made. In the case of delicate white wines, the must is fermented for four to six weeks at about 60F/16C. With more robust red wines, the must is fermented at a temperature between 65 and 80F/1827C in contact with the skins, to extract pigments, tannins, and flavor. This phase may last for 4 to 14 days (less if heat or a carbon dioxide treatment is applied). Then the must is separated from the skins and fermented again for a total of two to three weeks. One of the most critical variables during fermentation is temperature. The lower the temperature, the slower and longer the fermentation, and the more aromatic molecules acc.u.mulate.

The main fermentation is considered complete when essentially all the sugar in the must has been converted into alcohol. A wine with no residual sugar is called dry. dry. Sweet wines are made by stopping the fermentation before all the sugar has been consumed, or more commonly, by adding some reserved sweet grape juice to the dry wine after its yeast has been removed. Sweet wines are made by stopping the fermentation before all the sugar has been consumed, or more commonly, by adding some reserved sweet grape juice to the dry wine after its yeast has been removed.

OPPOSITE: Making red and white wines. White wines are fermented at a lower temperature and without the grape skins and seeds; they're also clarified at a lower temperature, in part so that they won't cloud when served chilled. Making red and white wines. White wines are fermented at a lower temperature and without the grape skins and seeds; they're also clarified at a lower temperature, in part so that they won't cloud when served chilled.

Malolactic Fermentation Winemakers sometimes allow or even induce a second bacterial fermentation in the new wine after the main yeast fermentation. The bacterium Winemakers sometimes allow or even induce a second bacterial fermentation in the new wine after the main yeast fermentation. The bacterium Leuconostoc oenos Leuconostoc oenos consumes the wine's malic acid and converts it into lactic acid, which is less strong and sour. This "malolactic" fermentation thus reduces the apparent tartness of the wine. It also produces a number of distinctive aroma compounds, among them b.u.t.tery diacetyl. (A relative of consumes the wine's malic acid and converts it into lactic acid, which is less strong and sour. This "malolactic" fermentation thus reduces the apparent tartness of the wine. It also produces a number of distinctive aroma compounds, among them b.u.t.tery diacetyl. (A relative of L. oenos, L. mesenteroides, L. oenos, L. mesenteroides, contributes the same compound to cultured b.u.t.ter itself!) Some winemakers work to prevent a spontaneous malolactic fermentation from developing, so that they can retain the sharpness and flavor of the original wine. contributes the same compound to cultured b.u.t.ter itself!) Some winemakers work to prevent a spontaneous malolactic fermentation from developing, so that they can retain the sharpness and flavor of the original wine.

Maturation Once fermentation is complete, the new wine is drained out of the fermentation tanks to begin the work of clarification and aging, in which the cloudy, rough-tasting liquid develops into a clear, smooth one. Once fermentation is complete, the new wine is drained out of the fermentation tanks to begin the work of clarification and aging, in which the cloudy, rough-tasting liquid develops into a clear, smooth one.

Racking and Fining The solid particles of grape and yeasts are cleared from the wine by the process of racking: letting the yeast cells and other large particles settle, carefully drawing the wine off the sediment into a new container, and repeating the process every few months. Interesting exceptions to this rule are wines intentionally aged for months or even years The solid particles of grape and yeasts are cleared from the wine by the process of racking: letting the yeast cells and other large particles settle, carefully drawing the wine off the sediment into a new container, and repeating the process every few months. Interesting exceptions to this rule are wines intentionally aged for months or even years sur lie, sur lie, or "on the lees," in contact with the yeast sediment, whose cells slowly break apart and contribute more flavor and body to the wine. Champagne and Muscadet are two wines that are aged on the lees. or "on the lees," in contact with the yeast sediment, whose cells slowly break apart and contribute more flavor and body to the wine. Champagne and Muscadet are two wines that are aged on the lees.

The cool racking temperatures - less than 60F/16C for red wines, around 32F/0C for whites - reduce the solubility of all the dissolved solids, and cause the wine to cloud up with a fine precipitate of various complexes of proteins, carbohydrates, and tannins. Late in the racking procedure, the wine may be fined fined: that is, a substance will be added to the wine that attracts these suspended particles to itself, and then settles to the bottom, carrying them with it. Gelatin, egg white, bentonite clay, and synthetic materials are used. Any particles remaining in the wine after racking and fining can be removed by pa.s.sing it through a centrifuge or filter. Winemakers may choose to limit or omit the fining and filtration steps, since they remove some flavor and body along with the undesirable particles.

Brettanomyces, the Controversial Barrel YeastSome wines, including cla.s.sic reds from Burgundy and Bordeaux, develop striking and unusual aroma notes suggestive of the barnyard or horse stable. Oenologists have recently discovered the major source of these aromas to be a group of yeasts in the genus Brettanomyces, Brettanomyces, which readily colonize wine barrels. At low levels, their unusual aromas may suggest tobacco leaf; they also include smoky, medicinal, clove-like, and musty notes (the barnyard notes come from ethyl phenols and isovaleric and isobutyric acids). Some wine lovers consider the "brett" aroma a defect caused by contamination and inadequate winery sanitation, while others appreciate it as an intriguing contribution to the variety and complexity of wine flavors. which readily colonize wine barrels. At low levels, their unusual aromas may suggest tobacco leaf; they also include smoky, medicinal, clove-like, and musty notes (the barnyard notes come from ethyl phenols and isovaleric and isobutyric acids). Some wine lovers consider the "brett" aroma a defect caused by contamination and inadequate winery sanitation, while others appreciate it as an intriguing contribution to the variety and complexity of wine flavors.

Barrel Aging New wine has a raw flavor and a strong, simple, fruity aroma. As the wine rests after fermentation, a host of chemical reactions slowly proceeds, and results in the development of balance and complexity in the flavor. If the wine is being held in a new wood barrel, it also absorbs various substances from the wood that either provide flavor directly - for example, vanilla-like vanillin and the coconut-woody oak lactones - or that modify the wine's own flavor molecules. In traditional winemaking, the months during which the wine is racked and shifted from container to container are a time when the wine's chemical evolution is directed by periodic exposure to the air. In the presence of oxygen, the tannins, anthocyanin pigments, and other phenolic compounds react with each other to form large complexes, so the wine's astringency and bitterness decline. Some of the molecules that provide aroma break apart or react with oxygen and each other to form a new suite of aromas, so fruity, floral notes fade in favor of a more subdued general "wineyness." White and light red wines are generally bottled young, after 612 months, with a fairly fresh, fruity bouquet, while astringent dark reds may require a year or two to develop and smooth out. New wine has a raw flavor and a strong, simple, fruity aroma. As the wine rests after fermentation, a host of chemical reactions slowly proceeds, and results in the development of balance and complexity in the flavor. If the wine is being held in a new wood barrel, it also absorbs various substances from the wood that either provide flavor directly - for example, vanilla-like vanillin and the coconut-woody oak lactones - or that modify the wine's own flavor molecules. In traditional winemaking, the months during which the wine is racked and shifted from container to container are a time when the wine's chemical evolution is directed by periodic exposure to the air. In the presence of oxygen, the tannins, anthocyanin pigments, and other phenolic compounds react with each other to form large complexes, so the wine's astringency and bitterness decline. Some of the molecules that provide aroma break apart or react with oxygen and each other to form a new suite of aromas, so fruity, floral notes fade in favor of a more subdued general "wineyness." White and light red wines are generally bottled young, after 612 months, with a fairly fresh, fruity bouquet, while astringent dark reds may require a year or two to develop and smooth out.

Most wines are made by blending two or more different varieties, and this important test of the winemaker's art occurs just before bottling. The final wine may then be filtered to remove any remaining microbes and haze, and given a final dose of sulfur dioxide to prevent microbial growth during storage. It may also be pasteurized. This practice is not limited to inexpensive wines. The Burgundy wines of Louis Latour are flash-heated for 23 seconds at 165F/72C, a treatment that is said not to have a detrimental effect on the wine's continuing flavor development.

Corks, Cork Taints, Corked WineCork is the outer protective layer of an evergreen oak, Quercus suber, Quercus suber, that is native to the western Mediterranean. Where most tree bark is fibrous, cork is composed of tiny air cells. Nearly 60% of the cell wall in cork is made up of that is native to the western Mediterranean. Where most tree bark is fibrous, cork is composed of tiny air cells. Nearly 60% of the cell wall in cork is made up of suberin, suberin, a complex waxy substance similar to the cutin that coats many fruits, and this makes cork water-resistant and long-lived. a complex waxy substance similar to the cutin that coats many fruits, and this makes cork water-resistant and long-lived.Cork is a natural, organic material, and as such can be infected by molds and bacteria. Molds produce moldy, earthy, mushroomy, and smoky smells. And certain bacteria can act on phenolic compounds in the cork and traces of chlorine disinfectant to produce trichloroanisole, an especially unpleasant and potent molecule that smells like a dank cellar. It's estimated that cork taints spoil from 1 to 5 percent of the wine bottles stoppered with cork. The problem of "corked" wine has led wine producers to experiment with alternative stoppers, including metal caps and stoppers made from foamed plastic.

Bottle Aging After a period of a few months to two years in barrels or tanks that allow controlled contact with oxygen, the wine goes into impermeable gla.s.s bottles. For the last two centuries, the standard stopper for wine bottles has been cork, which is made from the bark of a species of oak. Because cork can be the source of off-flavors, some wine producers are now using metal and plastic stoppers (see box below). After a period of a few months to two years in barrels or tanks that allow controlled contact with oxygen, the wine goes into impermeable gla.s.s bottles. For the last two centuries, the standard stopper for wine bottles has been cork, which is made from the bark of a species of oak. Because cork can be the source of off-flavors, some wine producers are now using metal and plastic stoppers (see box below).

Wine continues to be affected by oxidation long after it leaves the cask. It picks up some air when it is filled into the bottle, and the bottle is sealed with a small s.p.a.ce between wine and cork. So while oxidation is greatly slowed in the bottle, it does continue, though it may be outweighed by a different set of reactions, "reductive" rather than oxidative. The chemical changes that occur are not well understood, but include the ongoing liberation of aromatic molecules from nonaromatic complexes, and aggregation reactions among tannins and pigments that further lower astringency and cause a shift in pigment hues, usually toward the brown.

White wines and light-red roses benefit from about a year of bottle aging, during which time the aroma develops and the amount of free, odorous sulfur dioxide decreases. Many red wines improve greatly after a year or two in the bottle, and some may develop for decades. All wines have a finite life span, and their quality eventually declines. White wines develop overtones of honey, hay, wood, and chemical solvents; red wines lose much of their aroma and become flat-tasting and more plainly and harshly alcoholic.

Special Wines In the last few pages, I've described the general method for making dry table wines, which usually accompany meals. Sparkling, sweet, and fortified wines are often sipped on their own. Here is a brief account of their special qualities and how they are produced.

Sparkling Wines: Champagne and Others Sparkling wines delight by emitting bubbles that catch the light and p.r.i.c.k the tongue. The bubbles come from the wine's considerable dissolved reserves of carbon dioxide gas, a by-product of yeast metabolism that ordinarily escapes into the air from the surface of the fermenting wine. To make a sparkling wine, the wine is confined under pressure - either in the bottle or in special tanks - so that the carbon dioxide can't escape as it's produced, and instead comes to saturate the liquid. A bottle of Champagne holds a gas pressure of 34 atmospheres, somewhat higher than the pressure in car tires, and contains about six times its volume in carbon dioxide! Sparkling wines delight by emitting bubbles that catch the light and p.r.i.c.k the tongue. The bubbles come from the wine's considerable dissolved reserves of carbon dioxide gas, a by-product of yeast metabolism that ordinarily escapes into the air from the surface of the fermenting wine. To make a sparkling wine, the wine is confined under pressure - either in the bottle or in special tanks - so that the carbon dioxide can't escape as it's produced, and instead comes to saturate the liquid. A bottle of Champagne holds a gas pressure of 34 atmospheres, somewhat higher than the pressure in car tires, and contains about six times its volume in carbon dioxide!

When we remove the cork and thus relieve the pressure, the excess carbon dioxide leaves the solution in the form of gas bubbles. The bubbles form wherever the liquid comes into contact with a microscopic air pocket into which the dissolved carbon dioxide can diffuse. In the gla.s.s, the bubbles form on scratches and other surface imperfections. The refreshingly sharp p.r.i.c.kle in the mouth comes from the irritating dose of carbonic acid that the bubbles deliver as they redissolve into the unsaturated layer of saliva.

Many countries have their own versions of sparking wine, which range from the carefully crafted to the ma.s.s-produced. The best-known example of a sparkling wine is Champagne, which strictly speaking is the wine made in the region of that name east of Paris, and accounts for less than a tenth of the world's production of sparkling wine. From the late 17th century to the late 19th, Champagne evolved to become the most refined expression of this style. The French invented the method of inducing a bubble-making second fermentation in the bottle, and this methode champenoise methode champenoise has become a worldwide benchmark for making fine sparkling wines. has become a worldwide benchmark for making fine sparkling wines.

Making Champagne The first stage in making Champagne is to produce a base wine, which is made primarily from Pinot Noir and/or Chardonnay grapes. Next comes the secondary fermentation, which must be carried out in a closed container in order to retain the gas. Sugar is added to the dry base wine as food for the yeast. The wine, sugar, and yeast are put into individual bottles, corked, clamped, and kept at about 55F/13C. The first stage in making Champagne is to produce a base wine, which is made primarily from Pinot Noir and/or Chardonnay grapes. Next comes the secondary fermentation, which must be carried out in a closed container in order to retain the gas. Sugar is added to the dry base wine as food for the yeast. The wine, sugar, and yeast are put into individual bottles, corked, clamped, and kept at about 55F/13C.

Though the secondary fermentation is usually complete after about two months, the wine is left to age in contact with the yeast sediment for anywhere from a few months to several years. During this time, most of the yeast cells die, fall apart, and release their contents into the wine, giving it a distinctive, complex flavor with toasted, roasted, nutty, coffee, even meaty notes (due in large part to complex sulfur compounds). In addition to flavor, yeast proteins and carbohydrates will stabilize bubbles when they form in the gla.s.s, and help produce the very fine bubbles typical of Champagne. After aging on the yeast, the sediment is removed and the bottle topped off with additional wine, and finished with a small amount of aged wine mixed with sugar and brandy. The bottle is then recorked.

Making Other Sparkling Wines The traditional Champagne process is labor intensive, time consuming, and expensive. More affordable and less complex sparkling wines are made all over the world in a number of different ways. One is simply to minimize or eliminate aging on the yeast sediment. Others involve fermenting the base wine for the second time not in individual bottles, but in large tanks, or not fermenting again at all: the cheapest sparkling wines are simply carbonated as soft drinks are, with tanks of pressurized carbon dioxide. The traditional Champagne process is labor intensive, time consuming, and expensive. More affordable and less complex sparkling wines are made all over the world in a number of different ways. One is simply to minimize or eliminate aging on the yeast sediment. Others involve fermenting the base wine for the second time not in individual bottles, but in large tanks, or not fermenting again at all: the cheapest sparkling wines are simply carbonated as soft drinks are, with tanks of pressurized carbon dioxide.

Sweet Wines Table wines are generally fermented until they are Table wines are generally fermented until they are dry dry: that is, until the yeast consumes essentially all the grape's sugars and converts them into alcohol. Sweet or dessert wines with 1020% "residual" sugar are made in several different ways: An ordinary dry wine is sweetened with some unfermented grape juice, and the combination treated to prevent further fermentation with a dose of sulfur dioxide, or filtration that removes all yeast and bacteria from the wine.

Grapes are dried on the vine or after picking to concentrate their sugars to 35% or more of the grape weight. This leaves residual sugar in the wine when the yeasts reach their maximum alcohol level and the fermentation stops. German Trockenbeerenauslese Trockenbeerenauslese and Italian and Italian recioto recioto wines are examples. wines are examples.

Grapes are left on the vine past the first frost and picked when frozen (or frozen artificially), and then gently pressed while cold to separate the concentrated juice from the ice crystals. The concentrated juice ferments into a stable wine with residual sugar. German Eiswein Eiswein dates from around 1800. dates from around 1800.

The grapes are allowed to become infected with "n.o.ble rot," the mold Botrytis cinerea, Botrytis cinerea, which dehydrates the grapes, concentrates their sugars, and transforms their flavor and consistency. This method originated in the Tokaji region of Hungary around 1650, and was adopted in the German Rheingau by 1750 and in the Sauternes region of Bordeaux around 1800. which dehydrates the grapes, concentrates their sugars, and transforms their flavor and consistency. This method originated in the Tokaji region of Hungary around 1650, and was adopted in the German Rheingau by 1750 and in the Sauternes region of Bordeaux around 1800.

Enjoying Sparkling Wines In order to appreciate their sparkle, sparkling wines are best served very cold, around 40F/5C, in tall, narrow gla.s.ses that allow their rising bubbles to be admired for several seconds. Carbon dioxide is more soluble in water at low temperatures, so the bubbles will be smaller and longer-lasting in cold wine. Because soaps, fats, and oils cause bubbles to collapse (p. 639), bubbliness is reduced when our lips deposit lipstick or oils from food on the gla.s.s, or when the gla.s.s has been incompletely rinsed and carries traces of dish soap. In order to appreciate their sparkle, sparkling wines are best served very cold, around 40F/5C, in tall, narrow gla.s.ses that allow their rising bubbles to be admired for several seconds. Carbon dioxide is more soluble in water at low temperatures, so the bubbles will be smaller and longer-lasting in cold wine. Because soaps, fats, and oils cause bubbles to collapse (p. 639), bubbliness is reduced when our lips deposit lipstick or oils from food on the gla.s.s, or when the gla.s.s has been incompletely rinsed and carries traces of dish soap.

The n.o.ble Rot: Tokaji, Sauternes, and Others The n.o.ble rot (French The n.o.ble rot (French pourriture n.o.ble, pourriture n.o.ble, German German Edelfaule Edelfaule)Botrytis cinerea is also known as bunch rot, and it is mainly a destructive disease of grapes and other fruits. It becomes n.o.ble only in the right climatic conditions, when the initial infection in humid weather is followed by a dry period that limits the infection. In this situation, the mold does several useful things. It perforates the skin of the grape, thus allowing it to lose moisture and become concentrated during the subsequent dry period; it metabolizes some of the tartaric acid at the same time that it consumes some of the grape's sugars, so the balance between sweetness and acidity doesn't suffer; it produces glycerol, which lends the eventual wine an incomparably dense body; and it synthesizes a number of pleasing aroma compounds, notably the maple-sugar-like sotolon, mushroomy octenol, and a number of terpenes. The honeyed flavor of these wines can develop in the bottle for decades. is also known as bunch rot, and it is mainly a destructive disease of grapes and other fruits. It becomes n.o.ble only in the right climatic conditions, when the initial infection in humid weather is followed by a dry period that limits the infection. In this situation, the mold does several useful things. It perforates the skin of the grape, thus allowing it to lose moisture and become concentrated during the subsequent dry period; it metabolizes some of the tartaric acid at the same time that it consumes some of the grape's sugars, so the balance between sweetness and acidity doesn't suffer; it produces glycerol, which lends the eventual wine an incomparably dense body; and it synthesizes a number of pleasing aroma compounds, notably the maple-sugar-like sotolon, mushroomy octenol, and a number of terpenes. The honeyed flavor of these wines can develop in the bottle for decades.

Fortified Wines Fortified Fortified wines are so called because the strength of the base wine is boosted by the addition of distilled spirits to 1820% alcohol, a level that prevents spoilage by vinegar bacteria and other microbes. Fortification appears to have begun in the sherry-producing region of Spain sometime before 1600. Winemakers take advantage of the stability of fortified wines by exposing them to the air for months or years. They thus make a virtue of the normally undesirable oxidative changes in flavor that come with keeping leftover wine. Most fortified wines keep well for weeks in an opened bottle or decanter. wines are so called because the strength of the base wine is boosted by the addition of distilled spirits to 1820% alcohol, a level that prevents spoilage by vinegar bacteria and other microbes. Fortification appears to have begun in the sherry-producing region of Spain sometime before 1600. Winemakers take advantage of the stability of fortified wines by exposing them to the air for months or years. They thus make a virtue of the normally undesirable oxidative changes in flavor that come with keeping leftover wine. Most fortified wines keep well for weeks in an opened bottle or decanter.

Madeira Beginning in the 15th century, Portuguese ships embarking on long voyages to the Indies would pick up barrels of ordinary wine on the Portuguese island of Madeira. Sailors and producers soon found that the long barrel aging in extreme temperatures and with constant agitation produced an unusual but attractive wine. By 1700, ships were sailing to the East Indies and back just to age the barrels of Madeira stored on board; by 1800, the wine was being fortified with brandy and hot-aged on the island. Today, the base wine, which can be white or red, is fortified, sometimes sweetened, then artificially heated to a temperature around 120F/50C, where it's held for three months before slowly cooling down again. It's then aged in barrels in a sherry-like Beginning in the 15th century, Portuguese ships embarking on long voyages to the Indies would pick up barrels of ordinary wine on the Portuguese island of Madeira. Sailors and producers soon found that the long barrel aging in extreme temperatures and with constant agitation produced an unusual but attractive wine. By 1700, ships were sailing to the East Indies and back just to age the barrels of Madeira stored on board; by 1800, the wine was being fortified with brandy and hot-aged on the island. Today, the base wine, which can be white or red, is fortified, sometimes sweetened, then artificially heated to a temperature around 120F/50C, where it's held for three months before slowly cooling down again. It's then aged in barrels in a sherry-like solera solera system (below) before bottling. There are several different styles of Madeira, from sweet to nearly dry. system (below) before bottling. There are several different styles of Madeira, from sweet to nearly dry.

Styles of PortToday there are several distinct styles of port, the most common of which are these: Vintage port is made from the best grapes in especially good years, and is barrel-aged for two years and bottle-aged unfiltered for a minimum of 10 years, often many decades longer. It's dark and fruity, must be decanted off its considerable sediment, and must be drunk within a few days after the bottle is opened.

Tawny port, so named for its brown color (the result of precipitation of the red pigments), is typically barrel-aged for 10 years before being filtered and bottled. It is much more oxidized than vintage port of the same age, and can be kept in an opened bottle or decanter for weeks.

Ruby port is an intermediate product, aged for three years in barrels before filtration and bottling.

Port The name The name port port was originally the English term for any Portuguese wine. The addition of brandy was introduced in the 18th century as a way of guaranteeing that the wines would get to England in drinkable condition, and it resulted in the development of an unusual group of sweet red wines. Port is made by stopping the fermentation of the base red wine while about half the grape sugar is left, and fortifying it with distilled spirits to give an alcohol content around 20%. The wine is then aged in barrel and finally in bottle for anywhere from two to 50 years. Older ports are characterized by the maple-like compound sotolon and other sweetly aromatic compounds, likely products of browning reactions, which are also found in botrytized wines and sherries. was originally the English term for any Portuguese wine. The addition of brandy was introduced in the 18th century as a way of guaranteeing that the wines would get to England in drinkable condition, and it resulted in the development of an unusual group of sweet red wines. Port is made by stopping the fermentation of the base red wine while about half the grape sugar is left, and fortifying it with distilled spirits to give an alcohol content around 20%. The wine is then aged in barrel and finally in bottle for anywhere from two to 50 years. Older ports are characterized by the maple-like compound sotolon and other sweetly aromatic compounds, likely products of browning reactions, which are also found in botrytized wines and sherries.

Sherry Sherry is a fortified, oxidized white wine that was developed in the Spanish port city Jerez de la Frontera, whose name was Anglicized to "sherry" around 1600. True sherry gets its distinctive flavor from the Sherry is a fortified, oxidized white wine that was developed in the Spanish port city Jerez de la Frontera, whose name was Anglicized to "sherry" around 1600. True sherry gets its distinctive flavor from the solera solera system of maturing wine, which was developed early in the 19th century. The solera is a series of casks, each initially containing the fortified new wine of a particular year, but not completely filled, so a significant area of wine surface is in direct contact with the air. The wine therefore develops a characteristic intense, oxidized flavor. As the cask contents evaporate and become more concentrated, each is replenished with wine from the next younger cask. The final wine is bottled from the casks containing the oldest wines, and thus is a blend of wines from many different vintages and degrees of development. system of maturing wine, which was developed early in the 19th century. The solera is a series of casks, each initially containing the fortif