White wine… thousands years of culture
White wine exists since at least 2,500 years ago. In ancient Greece, wine was believed to be “the drink of Dionysus”. Dionysus was God of fertility, vegetation and vine; according to mythology he had taught men winemaking techniques. In fact during the festivities held in honor of Dionysus, rivers of wine were poured out.
Wine was prescribed by Hippocrates to his patients since the fifth century BC. Indeed remedies to diseases would refer to: “winy white wine” and “sour white wine”, letting us know that at that time there were already diversity of grapes and production techniques. In ancient Rome, however, wine was considered “stuff for the rich”: the patricians, and just males among them. Very slowly, over time, with the advent of new military conquests and with the addition of new vines in northern Italy and France, even the Romans were able to achieve a level of quality for their wine that would compare to Greeks’. During the eighteenth century, Paris started a new trend about drinking dry white whine. In order to avoid the government duty, Parisians drank directly in the producers cellars.
The progresses in the glass industry (thanks to coal, of course) made it possible to democratize the use of the bottle, allowing a considerable increase in the distribution of wine.
White wine history
At the end of the Middle Age, vine growing experienced a revival in Northern Europe, thanks to the navigable rivers. The populations of the Rhine and Danube, in Germany, exploited these rivers to export their white wine. In the Mediterranean sea, the ever rival Republics of Genoa and Venice, would supply their troops with greek wine. The port of Monemvasia exported such massive quantities of white wine to give the vine its own name, nowadays known as Malvasia. The Crusaders, who also discovered the Muscat wine, imported from the East as well. Then they planted the vineyards in northern Europe, in France and Spain.
In 1453, the rise of the Ottoman Empire caused a massive drop in wine trading between Northern Europe and Eastern Mediterranean. Thus Spain began a strong commercialization of white wines in England and Holland.
The period of the nineteenth century that preceded the arrival of phylloxera was the real viticulture golden age. The Industrial Revolution enriched the bourgeoisie, who was a customer of the best wines. The rural exodus to the factories created a vast market for the wines of mass production as well.
An excellent example of white wines production was viticulture in Germany. Thanks to the technique of the late harvest, wines with little sugar achieved balance despite their noticeable acidity. The Institute of Enology at Geisenheim was born in 1872.
During the twentieth century, the cultivation of vines in countries where it was previously unknown was booming. The only obstacle was the excessive temperature experienced during fermentation. The use of larger containers led to issues with fermentation, because the yeast built up a heat that was not being dispersed. Above 35° C, the microorganisms were beginning to suffer and the fermentation slowed down and then stopped, so that, after cooling the wine, a new inoculation was necessary in order to start up the fermentation again.
During this period, in California, new technologies were developed to keep the must temperature under control during its fermentation. They revolutionized the kind of white wine produced so that European wines, made in a way that ruins the fruity of the taste, were the antithesis of these new wines, characterized by a very fruity taste and refreshing liveliness. Over the years 60 and 90 of the twentieth century, American methods of vinification reached Europe and their refrigeration technology is still being used today in all white wines producing regions.
In practice, wine is an integral part of human history. Wine accompanied men in their evolution, settling with them on several continents, from Europe to America, to Oceania. Africa and Asia had less of an impact however, because of their climate, customs and traditions.
A key aspect of the kind of wine being produced is the location of the vineyards. Many viticultural countries produce white wines. Usually, the dry white wines producing vineyards are located in areas in the north or in the heights. In fact, the white grape needs a colder climate to ripen than red grapes do. The tannins lack of maturity poses no problem because the they are not extracted during the pressing step. The white wine liveliness comes from the acidity of the grapes: to that end they are harvested some time before ripening.
White wine components
Let’s examine some of the white wine production key components.
They are crystals of refined sucrose (sugar used in the process of sugaring).
Sugars are essential elements for the production of wine. They are naturally present in the berries juice.
L-tartaric acid is the main organic acid found in wine.
Organic acids contained in the grape pulp are mainly malic acid and tartaric acid. The tartaric acid, produced from the leaves, is present in wine in amounts equal to 5-7 g/l. Malic acid is present in maturing grapes and its rate decreases with their ripening. At harvest its content ranges from 2 to 7 g/l. Actually, the amount of malic acid depends on many factors: the kind of grape, the soil, the climate. Grapes grown in warm climatic regions have lower malic acid rates as the acid degradation is accelerated.
The white wine must is usually more acidic than red wine’s, simply because the grapes are harvested before their fully mature.
The C vitamin (ascorbic acid) is present in grapes and must in an amount of about 50 mg/l. Its function is to protect the must from oxidation. B1 vitamin, or thiamine, is present in grapes in amounts equal to 0.2-0.5 mg/l. It is a key element to the good growth of yeasts, which in turn are critical to the alcoholic fermentation success. The amount of B1 vitamin naturally present in must produced with healthy grapes is enough to let yeast properly function.
The minerals contained in the must are mainly sodium, calcium, potassium and magnesium. Wines produced in the southern areas are usually mildly acidic. The absence of acidity is considered by experts a wine defect.
White wine is produced from the alcoholic fermentation of must coming from white grapes or black grapes with colorless pulp.
The winemaking process takes place with specific treatments designed to preserve the wine white natural transparent-yellow color. Color is not the only hallmark of the various wine assortments: every kind of vine gives life to a different kind of wine. The way grapes are processed and the amount of sugar contained by the fruits all end up contributing to an endless myriad of variations.
White wine is produced from grapes harvested in green or yellow vineyards. The most common white wine is dry, which can be acidic or aromatic, produced by total fermentation of the must, which turns all the sugars into alcohol and carbon dioxide.
In order to produce sweet white wines, be them dessert, semi-sweet or fortified, winemakers apply a technique called “mutation”. Mutation consists in stopping the fermentation before all the sugar is transformed into alcohol. The effervescence shown by some wines, instead, is due to the presence of carbon dioxide produced during the fermentation itself. Carbon dioxide is the gas responsible for the classic bubbles on the surface and the light foam flowing at the opening of the bottle.
The making of White Wine
White wines are produced from white grapes or red grapes with white flesh (in fact, black grapes with black pulp, called dyer grapes, would dye the juice). Once the harvest is done, the grapes get crushed in order to extract the juice, called the must, which in turn is put into a fermentation bathtub to make it ferment.
The maturity of the grape harvest varies depending on the kind of wine to obtain. In order to produce certain kinds of sweet or fortified white wine, it is necessary to encourage the concentration of sugars in the pulp. In fact, as the ripening process goes through, the amount of sugar in the pulp increases and the amount of acids decreases. On the other side, in order to produce a dry white wine, grapes generally get harvested eight days before grapes have fully ripened. After harvesting, the grapes must be quickly moved from the vineyard to the winery in order both to protect them from oxygen and to avoid crushing them due to a lenghty transport. If there’s a long distance between vineyard and winery, the harvested grapes can be refrigerated with dry ice and protected from oxygen via nitrogen.
Some producers who grow their vines with organic or biodynamic methods, retain the wine cap, because it’s a sign of quality and is free from any synthetic chemical that could be harmful to the yeast. Proper metabolism of yeasts is guaranteed by the turbidity of the must and consequently the fermentation done in small vats or in barriques does not require a cooling process.
When making a dry white wine, the fermentation continues until the sugars are completely consumed. The wine is then decanted to remove any dregs left. During barrique fermentation, the temperature often exceeds 20° C. After alcoholic fermentation is done, the wine may undergo malolactic fermentation, a second fermentation that removes acidity due to certain bacteria that transform malic acid into lactic acid. This process, which decreases the pungent acidity, it is not always desired. Sweet white wines do not undergo malolactic fermentation because the development of lactic bacteria leads to sugars breakdown and increased acidity. This alteration is called “sweet wine disease”, “sweet-and-sour” or “mannitic fermentation”.
Élevage or Raising
The barrel plays a dual role: the wine flavors giving a scent to grilled bread, butter, vanilla and provides a very small amount and adjust oxygen passing through the timber wall. The oxygen helps to cure the compounds of wine making it less aggressive and more balanced.
At this point of the production, premium wines get refined or “raised” by putting them into barriques. This process is done in the same location where must fermented. The barrique plays a dual role: flavors the wine giving it a grilled bread, butter, vanilla scent and adds a small amount of oxygen passing through the timber wall. Oxygen helps polymerizing wine components making a smooth and balanced product.
The assemblage is a production process where different blends of wine are mixed together in order to achieve the desired cuvee. It’s possible to assemble different grapes, vintages or cuvees. The assemblage can be purely quantitative, in the case in which came together in several cuvee to obtain the desired volume, or can be qualitative. In this last case, the taster or a team of tasters find out the best amount of each wine to assemble in the final cuvee to achieve a product of excellent quality.
Clarification of wine
Clarification is what happens when dregs sink at the bottom of the barrique.
Clarification consists in removing the not soluble elements in suspension, from the hydroalcoholic solution which forms the wine.
Clarification takes place after the particles are deposited at the bottom of the wine vat. This operation may be sped up by using oenological glues, which bind to the insoluble particles present in the wine and bring them to the bottom.
Tannic or gallotannic acid, casein, gelatin or isinglass are commonly used to clarify white whine.
Stabilization aims at preserving the solubility of the elements dissolved into the wine during the storage period in the bottle. Tartaric acid crystallizes because storage its solubility is affected by temperature. Storing the product in the cold decreases it.
Various ways to achieve stabilization:
- Before conditioning, cool wine for several weeks at a low temperature, close enough to freezing, so that salt precipitates. Dispose of crystals by using a filtration technique.
- Add metatartaric acid to the wine. Metatartaric acid is a tartaric acid polymer, although this substance mode of action is unknown. It is believed that this acid prevents the microscopic crystals from growing, but this is an effect that does not last long: between six and eighteen months, because heat tends to hydrolyze the crystals.
- Electrodialysis: electric current flowing between two plates attracts wine ions, eliminating them. This approach does not just affect tartaric acit, but also potassium and calcium. The latter is responsible for the formation of insoluble bitartrate.
- Sur lie aging. Thanks to this technique it’s possible to achieve a better white wines tartaric stability. This mannoprotein, coming from yeasts hydrolysates, helps salts retaining their solubility.
- Another way to stabilize wine is to prevent tartaric precipitation by adding cellulose gum.
Stabilization is also needed if there is a presence of unstable proteins that are likely to create a visual wine defect called “protein breakage”. In this case, it becomes necessary to use bentonite to precipitate them and later get them removed by means of decanting and filtration.
Filtration and conditioning
Before being sold to customers, wine is filtered, if necessary, then conditioned. The filtration is about making the liquid pass through a filter element intended to capture the fine particles located on the surface. The most used filtration techniques include employing: filtration plates, fossil flour, carton and tangential filtration (the motion of the fluid being filtered flows tangentially with respect to the surface of the filter).
Conditioning is the operation done to transfer the wine in a container to be marketed. For a long time, customers used to go to the vintner and fill their jugs or bottles with wine that was kept inside barrels. The introduction of the glass bottle in the market has revolutionized the wine world: the absence of decanting prevents oxygen from getting in contact with wine. This has marked a sharp improvement in the delivered product quality.
Wine bottles have various shapes and thicknesses. Effervescent wine got the most emblematic bottle shape. Due to the pressure exerted by its gases, the bottle is made with a thick glass. Many countries have adopted a more tapered bottle for white wines than for red wines.
White wine tasting
White wine color variety reflects the diversity in the types of grapes it’s made from. Yellow is commonly associated with white wines, although there are many shades of color that are attributed to them on the basis of visual inspection.
In the color scale, white wine can be described as almost colorless. A young white usually has a pale greenish or pale yellow tint. Its color yellows and darkens with the passage of time and during the aging process. It slowly turns turns to gold, copper and finally amber. One of the darkest wines in the world is made from a white grape, the Pedro Ximenez.
White wine aromas cover almost all of the wine aroma wheel. To describe the aromas you rely on olfactory characteristics found in the glass. “Odorous” substances are varied in nature, their classification is made by association with known reference natural aromas. White wine gives off usually fruity, floral and mineral aroms, but it’s not limited to them.
Fruity flavors include citrus fruits (lemon and grapefruit), white fruits (apple, quince, peach, apricot), nuts (walnut, hazelnut) and exotic fruits (pineapple, mango, lychee). Of course, fruity aromas include cooked fruit (compotes, jams, candied fruit) too.
Floral aromas include acacia flowers, verbena, violet, etc.
Other aromas emanating from white wine are formed during the raising phase. Élevage in the barrel brings hints of vanilla, butter, croissants, toasted bread, caramel. Due to its low amounts of tannins, white wine gives a different feeling of balance than red wine when tasted in the mouth. The balance is not just based on the relationship between alcohol and acidity, as in red wines, but there is another component as well: sugar. In fact, sugar is what allows the balance between alcohol and acidity, both for sweet and fortified white wines.
The élevage in barrels brings a woody note: oak tannins make it structured. Some wines are best aged in new barrels, that is, barrels that have never been used previously.
White wine glasses
Since when glass containers exist, specific glasses have been created for each kind of wine. Sparkling wines are served in flutes and cups. Flute is especially used for tastings: its shape focuses the aromas to the nose of the taster and his depth allows to appreciate the finesse of the bubbles that rise to the surface. The use of the cup in tastings is not recommended because its shape is too flared. In fact, failing to keep the foam edge, gases and aromas get dispersed too quickly. Legend has it that the shape of this glass has been inspired by Marquise de Pompadour’s breast shape. She lived in a time when most wines were softer and less aromatic. Flute came into vogue since the 30s, when drinking drier effervescent wines became common. White wine glasses are generally taller and thinner than those used for red wine.
White wine kinds
Dry white wine
White wine is almost devoid of sugar: the rate of sugar is generally lower than 4g/l. It is difficult to process, because the balance resides just on two parameters: acidity and alcohol. Consumers refer to this classic kind of white wine when they talk about white wine without giving further details.
In wine jargon, the techniques employed to work its must produce a “technical wine”. This is a scented, lively wine, that does not need to age. European white wines produced the “traditional way” have adapted very well to the new winemaking techniques.
Sweet and fortified white wines
Among sweet wines, a wide variety may be found: from the slightly sweet to the one featuring syrupy consistency.
In the production of sweet wines, fermentation is stopped prematurely. This is done so that sugar, naturally present in grapes, does not turn into alcohol. There are several techniques to control sugar concentration:
- “withering on the vine” or “late harvest”;
- “torsion of the pedicle”;
- “engraved ring”;
- Another quick and efficient way is to take advantage of the vine training system and break a part of the fruiting “canes” so that grapes upstream wither while grapes downstream develop naturally. Subsequent assembly of the two resulting grapes kinds in a vat or in a press, improves the final result;
- “withering out of the vine”, performed before pressing;
- noble rot is a grape alteration caused by the Botritys cinerea parasite. Noble rot increases grape dehydration and sugars concentration. As such, it may be employed as a way to control sugars concentration;
- hanging the grapes bunches in various ways and have them wither in a controlled way at a certain temperature;
- “grapes freezing and pressing” allows to press just the liquid part of the grape. Small crystals of frozen water remain in the press and only the sugary juice flows.
- cryoextraction is a recent technique designed to reproduce the above process in regions with a mild climate: grapes are artificially frozen before pressing.
Spumescent or “sparkling” wine is, in most cases, a white wine that contains carbon dioxide. Carbon dioxide is responsible for its effervescence and bubbles. During fermentation all wines are effervescent; in fact yeasts produce carbon dioxide during the alcoholic fermentation of all wines. In most cases, gas produced by fermentation evaporates and the resulting wine won’t be effervescent; it will be a still wine. The winemaking of sparkling wines aims at preserving the carbon dioxide dissolved in the wine:
- The “traditional method”, once called “method champenoise”, consists in creating a white or rosé applying the still wine production techniques.
- “Rural method” or “traditional method” is about halting fermentation by means of cold (in the past, winter was responsible for blocking the fermentation) so that residual sugar finish fermenting in the bottle, producing dissolved gas.
- The “transfer method”, the “ancestral Dioise process”, the “Martinotti-Charmat method”, the “continuous sparkling process” or “Russian method”.
- “Gasification method”: wine is bottled under pressure. This is the flavored sparkling wines vinification method, made famous by Champagne, used to baptize big ships at inauguration day.
Produced in most wine making countries, effervescent wine is associated with holidays and commemorative events.
White wine culinary aspects
White wine serving
In order to appropriately taste a wine, it has to be served at a proper temperature: it must be cool but not frozen. Between 8° and 9° C, freshness accentuates the vivacity of a sparkling wine bubbles and softens the sweetness of a sweet or fortified one.
On the other side, an aromatic dry wine must be served between 0 and 12° C in order to emphasize its vitality and give freshness to its flavorings.
Finally, the serving temperature for white wines must be between 12 and 14° C so that the tasters may perceive their aromas and structure.
Matching white wine with food
Wines and dishes are complementary and are compensate each other. For example, slightly sweet or savory dishes soften the acidity of white wine; wine emphasizes savory food and lightens the fat dishes. Sweet wine accompanies sweet and savory dishes dampening an excessive sugar weight.
During the aperitif, dry scented or sparkling wines go well with appetizers. According to tasting specialists, sugar or alcohol, and the liveliness of some fruity wines, have a saturating and stimulating effect on the taste buds.
Shellfish, molluscs and white wine
On the table, very dry, slightly mineral wines are recommended for oysters and seafood because their acidity tends to emphasize the molluscs salinity. Scented white is the best choice for shellfish, fish and boiled white meats. As for dishes accompanied by a sauce, white wine counterbalances the weight of the fats. If sauce is well balanced by a live ingredient (lemon juice or mustard), it is recommended to serve the dish with a sweet or dry wine aged in barrels, that is a richer and more consistent wine. Sweet wines, be them semisweet or fortified, go well with exotic dishes with sweet spices.
Fortified white wines, instead, are recommended for serving foie gras. Diversity in sparkling wines means that they can be matched with any kind of dish. In fact, they can be consumed from meals beginning to end.
Gastronomes generally prefer whites to reds to accompany cheese, because its acidity goes well with the fat present in dairy products. White wine is also perfect for desserts. All kinds of wine are indicated, however semisweet and fortified are the best. More than any other, white wine may be consumed between meals. This Anglo-Saxon and Germanic habit requires a semisweet or a dry and fruity wine.
White wine as a dishes ingredient
Serving at the table the same wine that has been used to prepare the dishes is an everyday gastronomers habit. Celebrated by artists, poets and writers, white wine is served as aperitif, table or dessert wine. It’s also drunk as refreshing beverage to be consumed before, during and after meals. A further use of white wine is in the kitchen. It is employed to de-glaze the cooking juices of some dishes or to soften the meat, taking advantage of its acidity and its flavor.
The only drawback: the beneficial effects on our organism do not equal those given by red wine, which contains a greater number of polyphenols.