недеља, 21. јул 2013.

Interesting: The Wine "Cork"

There are about 2,200,000 hectares of cork forest worldwide; 32.4% in Portugal, and 22.2% in Spain. Annual production is about 300,000 tons; 61.3% from Portugal, 29.5% from Spain, 5.5% Italy.
Once the trees are about 25 years old the cork is traditionally stripped from the trunks every nine years, with the first two harvests generally producing lower quality cork. The trees live for about 200 years.
The cork industry is generally regarded as environmentally friendly. The sustainability of production and the easy recycling of cork products and by-products are two of its most distinctive aspects. Cork Oak forests also prevent desertification and are a particular habitat in the Iberian Peninsula and the refuge of various endangered species.

As late as the mid-17th century, French vintners did not use cork stoppers, using oil-soaked rags stuffed into the necks of bottles instead.
Wine corks can be made of either a single piece of cork, or composed of particles, as in champagne corks; corks made of granular particles are called "technical corks".
Natural cork closures are used for about 80% of the 20 billion bottles of wine produced each year. After a decline in use as wine-stoppers due to the increase in the use of cheaper synthetic alternatives, cork wine-stoppers are making a comeback and currently represent approximately 60% of wine-stoppers today.

Because of the cellular structure of cork, it is easily compressed upon insertion into a bottle and will expand to form a tight seal. The interior diameter of the neck of glass bottles tends to be inconsistent, making this ability to seal through variable contraction and expansion an important attribute. However, unavoidable natural flaws, channels, and cracks in the bark make the cork itself highly inconsistent. In a 2005 closure study 45% of corks showed gas leakage during pressure testing both from the sides of the cork as well as through the cork body itself.

Since the mid-1990s, a number of wine brands have switched to alternative wine closures such as synthetic plastic stoppers, screw caps, or other closures. In some countries, screw caps are often seen as a cheap alternative destined only for the low grade wines; however, in Australia, for example, the majority of non-sparkling wine production now uses these caps as a cork alternative. These alternatives to real cork have their own properties, some advantageous and others controversial. For example, while screwtops are generally considered to offer a trichloroanisole (TCA) free seal they reduce the oxygen transfer rate to almost zero, which can lead to reductive qualities in the wine. TCA is one of the primary causes of cork taint in wine. However, in recent years major cork producers (Amorim, Álvaro Coelho & Irmãos, Ganau, Cork Supply Group, and Oeneo) have developed methods that remove most TCA from natural wine corks. Natural cork stoppers are important because they allow oxygen to interact with wine for proper aging, and are best suited for bold red wines purchased with the intent to age.

The study "Analysis of the life cycle of Cork, Aluminum and Plastic Wine Closures," commissioned by cork manufacturer Amorim and made public in December 2008, concluded that cork is the most environmentally responsible stopper, in a one-year life cycle analysis comparison with the plastic stoppers and aluminum screw caps.

недеља, 23. јун 2013.

V I N I F I C A T I O N

The vinification starts when the grapes arrive to the cellar. During the harvest bad bunches or grapes have to be discarded but the pickers may overlook them in the hurry of picking. Therefore a new sorting often takes place at a sorting table in the cellar.
It's important that the fermentation can be started as quickly as possible after the harvest to avoid any wild fermentation to start in an uncontrolled way.
To start primary fermentation yeast may be added to the must for red wine or may occur naturally as ambient yeast on the grapes or in the air. Yeast may be added to the juice for white wine.


FERMENTATION



The biochemical process that transforms fresh grape juice into wine is called fermentation. Yeast cells excrete enzymes that convert natural fruit sugars into almost equal quantities of alcohol and carbonic gas. This process ceases when the supply of sugar is exhausted or when the alcoholic level reaches a point that is toxic for the yeast enzymes (usually 15 to 16 percent, although certain strains can survive at 20 to 22 percent). Traditionally, winemakers racked their wine from cask to cask until they were sure that fermentation had stopped, but there are now many other methods that halt fermentation artificially. These can involve the use of heat, sulfur dioxide, centrifugal filtration, alcohol, pressure,
or carbonic gas.
• Heat There are various forms of pasteurization (for table wines), flash-pasteurization (for finer wines), and chilling operations that are used to stabilize wine. These operate on the basis that yeast cells are incapacitated at temperatures above 36°C, or below -3°C, and that yeast enzymes are destroyed above 65°C. Flash-pasteurization subjects wines to a temperature of about 80°C for between 30 seconds and one minute, whereas fully fledged pasteurization involves lower temperatures of 50 to 60°C for a longer period.
• Addition of sulfur dioxide or sorbic acid Dosing with one or more aseptic substances will kill off the yeasts.
• Centrifugal filtration or filtration Modern equipment is now capable of physically removing all the yeasts from a wine, either by filtration (simply pouring the wine through a medium that prevents certain substances from passing through) or by centrifugal filtration (a process that separates unwanted matter from wine—or grape juice, if used at an earlier stage—by so-called “centrifugal force”).
• Addition of alcohol Fortification raises the alcohol content to a level toxic to yeast.
• Pressure Yeast cells are destroyed by pressure in excess of eight atmospheres (the pressure inside a Champagne bottle is around six atmospheres).
• Addition of carbonic gas (CO2 ) Yeast cells are killed in the presence of 15 g per l or more of carbonic gas.


Yeast



The primary role of yeast is to convert the sugars present (namely glucose) in the grape must into alcohol. The yeast accomplishes this by utilizing glucose through a series of metabolic pathways that, in the presence of oxygen, produces not only large amounts of energy for the cell but also many different intermediates that the cell needs to function. In the absence of oxygen (and sometimes even in the presence oxygen), the cell will continue some metabolic functions (such as glycolysis) but will rely on other pathways such as reduction of acetaldehyde into ethanol (fermentation) to "recharge" the co-enzymes needed to keep metabolism going. It is through this process of fermentation that ethanol is released by the yeast cells as a waste product. Eventually, if the yeast cells are healthy and fermentation is allowed to run to the completion, all fermentable sugars will be used up by the yeast with only the unfermentable pentose leaving behind a negligible amount of residual sugar.
The most common yeast associated with winemaking is Saccharomyces cerevisiae which has been favored due to its predictable and vigorous fermentation capabilities, tolerance of relatively high levels of alcohol and sulfur dioxide as well as its ability to thrive in normal wine pH between 2.8 and 4. Despite its widespread use which often includes deliberate inoculation from cultured stock, S.cerevisiae is rarely the only yeast species involved in a fermentation. Grapes brought in from harvest are usually teeming with a variety of "wild yeast" from the Kloeckera and Candida genera. These yeasts often begin the fermentation process almost as soon as the grapes are picked when the weight of the clusters in the harvest bins begin to crush the grapes, releasing the sugar-rich must. While additions of sulfur dioxide (often added at the crusher) may limit some of the wild yeast activities, these yeasts will usually die out once the alcohol level reaches about 5% due to the toxicity of alcohol on the yeast cells physiology while the more alcohol tolerant Saccharomyces species take over. In addition to S. cerevisiae, Saccharomyces bayanus is a species of yeast that can tolerate alcohol levels of 17–20% and is often used in fortified wine production such as ports and varieties such as Zinfandel and Syrah harvested at high Brix sugar levels. Another common yeast involved in wine production is Brettanomyces whose presence in a wine may be viewed by different winemakers as either a wine fault or in limited quantities as an added note of complexity.


Sulfur dioxide



Sulfur dioxide has two primary actions, firstly it is an anti microbial agent and secondly an anti oxidant. In the making of white wine it can be added prior to fermentation and immediately after alcoholic fermentation is complete. If added after alcoholic ferment it will have the effect of preventing or stopping malolactic fermentation, bacterial spoilage and help protect against the damaging effects of oxygen. Additions of up to 100 mg per liter (of sulfur dioxide) can be added, but the available or free sulfur dioxide should be measured by the aspiration method and adjusted to 30 mg per liter. Available sulfur dioxide should be maintained at this level until bottling. For rose wines smaller additions should be made and the available level should be no more than 30 mg per liter.
In the making of red wine, sulfur dioxide may be used at high levels (100 mg per liter) prior to ferment to assist in color stabilization. Otherwise, it is used at the end of malolactic ferment and performs the same functions as in white wine. However, small additions (say 20 mg per liter) should be used to avoid bleaching red pigments and the maintenance level should be about 20 mg per liter. Furthermore, small additions (say 20 mg per liter) may be made to red wine after alcoholic ferment and before malolactic ferment to overcome minor oxidation and prevent the growth of acetic acid bacteria.
Without the use of sulfur dioxide, wines can readily suffer bacterial spoilage no matter how hygienic the winemaking practice.


Potassium sorbate



Potassium sorbate is effective for the control of fungal growth, including yeast, especially for sweet wines in bottle. However, one potential hazard is the metabolism of sorbate to geraniol which is a potent and unpleasant by-product. The production of geraniol occurs only if sorbic acid is present during malo-lactic fermentation. To avoid this, either the wine must be sterile bottled or contain enough sulfur dioxide to inhibit the growth of bacteria. Sterile bottling includes the use of filtration.
Some winemakers practice natural wine making where no preservative is added. Once the wine is bottled and corked, the bottles are put into refrigeration with temperatures near 5°C.




MALOLACTIC FERMENTATION



Malolactic fermentation is sometimes known as the secondary fermentation.
Occurs when lactic acid bacteria metabolize malic acid and produce lactic acid and carbon dioxide. This is carried out either as an intentional procedure in which specially cultivated strains of such bacteria are introduced into the maturing wine, or it can happen by chance if uncultivated lactic acid bacteria are present.
Malolactic fermentation can improve the taste of wine that has high levels of malic acid, because malic acid, in higher concentration, generally causes an unpleasant harsh and bitter taste sensation, whereas lactic acid is more gentle and less sour. Lactic acid is an acid found in dairy products. Malolactic fermentation usually results in an increase on the pH of the wine. This should be monitored and not allowed to rise above a pH of 3.55 for whites or a pH of 3.80 for reds. pH can be reduced roughly at a rate of 0.1 units per 1 gram/litre of tartaric acid addition.
The use of lactic acid bacteria is the reason why some chardonnays can taste "buttery" due to the production of diacetyl by the bacteria. All red wines go through complete malolactic fermentation, both to lessen the acid of the wine and to remove the possibility that malolactic fermentation will occur in the bottle. White wines vary in the use of malolactic fermentation during their making. Lighter aromatic wines such as Riesling, generally do not go through malolactic fermentation. The fuller white wines such as barrel fermented chardonnay, are more commonly put through malolactic fermentation. Sometimes a partial fermentation, for example, somewhere less than 50% might be employed.




POST-FERMENTATION PROCEDURES


Racking



Racking, often referred to as Soutirage or Soutirage traditionnel (in French), also filtering or fining, is a method in wine production of moving wine from one barrel to another using gravity rather than a pump, which can be disruptive to a wine. The process is also known as Abstich in German and travaso in Italian Draining the clear wine off its lees, or sediment, into another vat or cask is known as “racking” because of the different levels, or racks, on which the wine is run from one container into another. In modern vinification, this operation is usually conducted several times during vat or cask maturation. The wine gradually throws off less and less of a deposit. Some wines, such as Muscadet sur lie, are never racked.


Fining



In winemaking, fining is the process where a substance (fining agent) is added to the wine to create an adsorbent, enzymatic or ionic bond with the suspended particles, producing larger molecules and larger particles that will precipitate out of the wine more readily and rapidly. Unlike filtration, which can only remove particulates (such as dead yeast cells and grape fragments), fining can remove soluble substances such as polymerized tannins, coloring phenols and proteins; some of these proteins can cause haziness in wines exposed to high temperatures after bottling. The reduction of tannin can reduce astringency in red wines intended for early drinking. Many substances have historically been used as fining agents, including dried blood powder, but today there are two general types of fining agents — organic compounds and solid/mineral materials.
Organic compounds used as fining agents are generally animal based, a possible cause of concern to vegans. The most common organic compounds used include egg whites, casein derived from milk, gelatin and isinglass obtained from the bladders of fish. Pulverized minerals and solid materials can also be used, with bentonite clay being one of the most common, thanks to its effectiveness in absorbing proteins and some bacteria. Activated carbon from charcoal is used to remove some phenols that contribute to browning as well as some particles that produce "off-odors" in the wine. In a process known as blue fining, potassium ferrocyanide is sometimes used to remove any copper and iron particles that have entered the wine from bentonite, metal winery and vineyard equipment, or vineyard sprays such as Bordeaux mixture. Because potassium ferrocyanide may form hydrogen cyanide its use is highly regulated and, in many wine producing countries, illegal. Silica and kaolin are also sometimes used.
Some countries, such as Australia and New Zealand, have wine labeling laws that require the use of fining agents that may be an allergenic substance to appear on the wine label.
There is the risk of valuable aromatic molecules being precipitated out along with the less desirable matter. Some producers of premium wine avoid fining, or delay it in order to leach more flavor and aroma from the phenols before they are removed.


Cold stabilization



When wines are subjected to low temperatures, a crystalline deposit of tartrates can form a deposit in the bottle. Should the wine be dropped to a very low temperature for a few days before bottling, this process can be precipitated, rendering the wine safe from the threat of a tartrate deposit in the bottle. For the past 20 years, cold stabilization has been almost obligatory for cheap commercial wines, and it is now increasingly used for those of better quality as well. This recent trend is a pity because the crystals are, in fact, entirely harmless and their presence is a completely welcome indication of a considerably more natural,
rather than heavily processed, wine.


Filtration



While fining clarifies wine by binding to suspended particles and precipitating out as larger particles, filtration works by passing the wine through a filter medium that captures particles larger than the medium's holes. Complete filtration may require a series of filtering through progressively finer filters. Many white wines require the removal of all potentially active yeast and/or lactic acid bacteria if they are to remain reliably stable in bottle, and this is usually now achieved by fine filtration.
Most filtration in a winery can be classified as either the coarser depth filtration or the finer surface filtration. In depth filtration, often done after fermentation, the wine is pushed through a thick layer of pads made from cellulose fibers, diatomaceous earth or perlite. In surface filtration the wine passes through a thin membrane. Running the wine parallel to the filter surface, known as cross-flow filtration, will minimize the filter clogging. The finest surface filtration, microfiltration, can sterilize the wine by trapping all yeast and, optionally, bacteria, and so is often done immediately prior to bottling. An absolute rated filter of 0.45 µm is generally considered to result in a microbially stable wine and is accomplished by the use of membrane cartridges, most commonly polyvinylidene fluoride (PVDF). Certain red wines may be filtered to 0.65 µm, to remove yeast, or to 1.0 µm to remove viable brettanomyces only.


Bottling



A final dose of sulfite is added to help preserve the wine and prevent unwanted fermentation in the bottle. The wine bottles then are traditionally sealed with a cork, although alternative wine closures such as synthetic corks and screwcaps, which are less subject to cork taint, are becoming increasingly popular. The final step is adding a capsule to the top of the bottle which is then heated  for a tight seal.




RED WINES



Fermentation

After the grapes are destemmed and lightly crushed, they are pumped into a vat where fermentation may begin as early as 12 hours or as late as several days later. Even wines that will be caskfermented must start off in vats, whether they are old-fashioned oak foudres or modern stainless-steel tanks. This is because they must be fermented along with a manta, or cap, of grapeskins. To encourage fermentation, the juice may be heated and selected yeast cultures or partially fermented wine from another vat added. During fermentation, the juice is often pumped from the bottom of the vat to the top and sprayed over the manta to keep the juice in contact with the grapeskins. This ensures that the maximum color is extracted. Other methods involve the manta being pushed under the fermenting juice with poles. Some vats are equipped with crude but effective grids that prevent the manta from rising, others rely on the carbonic gas given off during fermentation to build up pressure, releasing periodically and pushing the manta under the surface; another system keeps the manta submerged in a “vinimatic,” a sealed, rotating stainless-steel tank, based on the cement-mixer principle. The higher the temperature during fermentation, the more color and tannin will be extracted; the lower the temperature, the better the bouquet, freshness, and fruit will be. The optimum temperature for the fermentation of red wine is 29.4°C. If it is too hot, the yeasts produce certain substances (decanoic acid, octanoic acids, and corresponding esters) that inhibit their own ability to feed on nutrients and cause the yeasts to die. It is, however, far better to ferment hot fresh juice than to wait two weeks (which is normal in many cases) to ferment cooler but stale juice. The fuller, darker, more tannic and potentially longer-lived winesremain in contact with the skins for anything between 10 and 30days. Lighter wines, on the other hand, are separated from the skins after only a few days.


Vin de goutte and Vin de presse



The moment the skins are separated from the juice, every wine is divided into two—free-run wine, or vin de goutte, and press wine, or vin de presse.
For as long as presses have been used, winemakers have been aware of the different color, body and aroma characteristics of wine made from the "free-run" juice compared to pressed juice. Free-run is the juice that has been extracted through the process of crushing, the natural break down of the grape cell walls during maceration and fermentation and by the own weight of the grape berries as they are loaded on top of each other in a press. Even among press juice there are compositional difference between the various "factions" of juice produced from initial pressing through subsequent (and usually harsher) pressing. Often winemakers will keep free-run and pressed juice separated for most of the winemaking process including malolactic fermentation and barrel aging with the options to later blend between them to make the most complete, balanced wine, bottle separately under different labels and price tiers or to discard/sell off the pressed fractions to another producer.
The main difference between free-run and pressed juice is that pressed juice often has lower acidity levels, higher potassium and pH level, more phenolic compounds such as tannins and more suspended solids such as natural gum and proteins. Some of these attributes can be positive influences on the wine with the increased phenolics offering more body, aroma characteristics (such as the varietal aromas from terpenes) and aging potential. Other attributes may have more negative influence such as increased astringency and bitterness, precursor for browning pigments in white wine, mouthfeel and balance issues (as well as potential microbial instability) from the increased pH and the enhance need for fining agents to assist in the clarification and stabilization of the wine with the increase in suspended solids.
The extent of these differences will be magnified or minimized based on the initial condition of the fruit after harvest (with moldy, damaged, sun-burnt or botryized grapes producing stark differences between free-run and pressed juice), the type of press used, the amount of pressure involve and the over amount of movement that the grapes are subject to that could impact how much the skins and seeds are scoured and torn.


Carbonic maceration



Carbonic maceration is a winemaking technique, often associated with the French wine region of Beaujolais, in which whole grapes are fermented in a carbon dioxide rich environment prior to crushing. Conventional alcoholic fermentation involves crushing the grapes to free the juice and pulp from the skin with yeast serving to convert sugar into ethanol. Carbonic maceration ferments most of the juice while it is still inside the grape, although grapes at the bottom of the vessel are crushed by gravity and undergo conventional fermentation. The resulting wine is fruity with very low tannins. It is ready to drink quickly but lacks the structure for long-term aging. In the most extreme case, such as with Beaujolais nouveau, the period between picking and bottling can be less than six weeks.During carbonic maceration, an anaerobic environment is created by pumping carbon dioxide into a sealed container filled with whole grape clusters. The carbon dioxide gas permeates through the grape skins and begins to stimulate fermentation at an intracellular level. The entire process takes place inside each single, intact berry. Ethanol is produced as a by-product of this process but studies have shown that other unique chemical reactions take place that have a distinctive effect on the wine.
The process of carbonic maceration occurs naturally in a partial state without deliberate intervention and has occurred in some form throughout history. If grapes are stored in a closed container, the force of gravity will crush the grapes on the bottom, releasing grape juice. Ambient yeasts present on the grape skins will interact with the sugars in the grape juice to start conventional ethanol fermentation. Carbon dioxide is released as a by product and, being denser than oxygen, will push out the oxygen through any permeable surface (such as slight gaps between wood planks) creating a mostly anaerobic environment for the uncrushed grape clusters to go through carbonic maceration. Some of the earliest documented studies on the process were conducted by the French scientist Louis Pasteur who noted in 1872 that grapes contained in an oxygen rich environment prior to crushing and fermentation produced wines of different flavors than grapes produced in a carbon dioxide rich environment. This was because the fermentation process had already started within the individual grape clusters prior to the introduction of yeasts during conventional fermentation.



WHITE WINES



Two initial operations distinguished the white-winemaking process from the red one: first, an immediate pressing to extract the juice and separate the skins, and, second, the purging, or cleansing, of this juice. But for white wines of expressive varietal character the grapes are now
often crushed and then macerated in a vinimatic for 12 to 48 hours to extract the aromatics that are stored in the skins. The juice that is run out of the vinimatic, and the juice that is pressed out of the macerated pulp left inside it, then undergoes cleansing and fermentation like any other white wine. With the exception of wines macerated in a vinimatic, the grapes are either pressed immediately on arrival at the winery or lightly crushed and then pressed. The juice from the last pressing is murky, bitter, and low in acidity and sugar, so only the first pressing, which is roughly equivalent to the free-run juice in red wine, together with the richest elements of the second pressing, should be used for white-wine production. Once pressed, the juice is pumped into a vat where it is purged, or cleansed, which in its simplest form means simply leaving the juice to settle so that particles of grapeskin and any other impurities fall to the bottom.
This purging may be helped by chilling, adding sulfur dioxide and, possibly, a fining agent. Light filtration and centrifugation may also be applied during this process.
After cleansing, the juice is pumped into the fermenting vat or directly into barrels if the wine is to be cask-fermented. The addition of selected yeast cultures occurs more often in the production of white wine because of the wine’s limited contact with the yeast-bearing skins and the additional cleansing that reduces the potential amount of wine yeasts available. The optimum temperature for fermenting white wine is 18°C, although many winemakers opt for between 10ºC and 17°C, and it is actually possible to ferment wine at temperatures as low as 4°C. At the lower temperatures, more esters and other aromatics are created, less volatile acidity is produced, and a lower dose of sulfur dioxide is required; on the other hand, the resulting wines are lighter in body and contain less glycerol. With acidity an essential factor in the balance of fruit and, where appropriate, sweetness in white wines, many products are not permitted to undergo malolactic conversion and are not bottled until some 12 months after the harvest. Oak-matured wines which, incidentally, always undergo malolactic conversion, may be bottled between 9 and 18 months, but wines that are made especially for early drinking are nearly always racked, fined, filtered, and bottled as quickly as the process will allow in order to retain as much freshness and fruitiness as possible.


ROSÉ WINES



A rosé (from French: rosé also known as rosado in Portugal and Spanish-speaking countries or rosato in Italy) is a type of wine that incorporates some of the color from the grape skins, but not enough to qualify it as a red wine. It may be the oldest known type of wine, as it is the most straightforward to make with the skin contact method. The pink color can range from a pale "onion"-skin orange to a vivid near-purple, depending on the grape varieties used and winemaking techniques. There are three major ways to produce rosé wine: skin contact, saignée and blending. Rosé wines can be made still, semi-sparkling or sparkling and with a wide range of sweetness levels from bone-dry Provençal rosé to sweet White Zinfandels and blushes. Rosé are made from a wide variety of grapes and can be found all across the globe.
When rosé wine is the primary product, it is produced with the skin contact method. Black-skinned grapes are crushed and the skins are allowed to remain in contact with the juice for a short period, typically one to three days. The must is then pressed, and the skins are discarded rather than left in contact throughout fermentation (as with red wine making). The longer that the skins are left in contact with the juice, the more intense the color of the final wine.
When a winemaker desires to impart more tannin and color to a red wine, some of the pink juice from the must can be removed at an early stage in what is known as the Saignée (from French bleeding) method. The red wine remaining in the vats is intensified as a result of the bleeding, because the volume of juice in the must is reduced, and the must involved in the maceration becomes more concentrated. The pink juice that is removed can be fermented separately to produce rosé.
In other parts of the world, blending, the simple mixing of red wine to a white to impart color, is uncommon. This method is discouraged in most wine growing regions, especially in France, where it is forbidden by law, except for Champagne. Even in Champagne, several high-end producers do not use this method but rather the saignée method.


SPARKLING WINES



Sparkling wine is a wine with significant levels of carbon dioxide in it making it fizzy. The carbon dioxide may result from natural fermentation, either in a bottle, as with the méthode champenoise, in a large tank designed to withstand the pressures involved (as in the Charmat process), or as a result of carbon dioxide injection.
Sparkling wine is usually white or rosé but there are many examples of red sparkling wines such as Italian Brachetto and Australian sparkling Shiraz. The sweetness of sparkling wine can range from very dry "brut" styles to sweeter "doux" varieties.
The classic example of a sparkling wine is Champagne, but this wine is exclusively produced in the Champagne region of France and many sparkling wines are produced in other countries and regions, such as Espumante in Portugal, Cava in Spain, Franciacorta, Trento DOC, Oltrepò Pavese Metodo Classico and Asti in Italy (the generic Italian term for sparkling wine being spumante) and Cap Classique in South Africa. Most countries reserve the word Champagne for a specific type from the Champagne region of France. The French terms "Mousseux" or "Crémant" are used to refer to sparkling wine not made in the Champagne region. German and Austrian sparkling wines are called Sekt. The United States is a significant producer of sparkling wine with producers in numerous states. Recently the United Kingdom, which produced some of the earliest examples of sparkling wine, has started producing sparkling wines again.


MÉTHODE CHAMPENOISE

The traditional method is the process used in the Champagne region of France to produce the sparkling wine known as Champagne. It is also the method used in Spain to produce Cava. It used to be known as the méthode champenoise, but the Champagne producers have successfully lobbied the European Union to restrict that term to wines from their region. Thus, wines from elsewhere may not use méthode champenoise when sold in the EU, and instead traditional method, méthode traditionnelle or the local language equivalent can be seen; for instance, in Germany the term used is "klassische flaschengärung". Consumers outside the EU may still see méthode champenoise on labels, but it is becoming less common.
After primary fermentation, blending (assemblage in Champagne) and bottling, a second alcoholic fermentation occurs in the bottle.

Second fermentation



The blended wine is put in bottles along with yeast and a small amount of sugar, called the liqueur de tirage, stopped with a crown cap or another temporary plug, and stored in a wine cellar horizontally for a second fermentation. Under the Appellation d'origine contrôlée, NV (non-vintage) Champagne is required to age for 3 years to develop completely. In years where the harvest is exceptional, a vintage (millesime) is declared and the wine must mature for at least five years.
During the secondary fermentation, the carbon dioxide is trapped in the wine in solution. The amount of added sugar determines the pressure of the bottle. To reach the standard value of 6 bars (600 kPa) inside the bottle, it is necessary to have 18 grams of sugar; the amount of yeast (Saccharomyces cerevisiae) is regulated by the European Commission (Regulation 1622/2000, 24 July 2000) to be 0.3 gram per bottle. The liqueur de tirage is then a mixture of sugar, yeast and still Champagne wine.

Aging on lees

Non-vintage wine from Champagne cannot legally be sold until it has aged on the lees in the bottle for at least 15 months. Champagne's AOC regulations further require that vintage Champagnes be aged in cellars for five years or more before disgorgement, but most top producers exceed the requirement, holding bottles on the lees for 6 to 8 years.

Riddling



After aging, the lees must be consolidated for removal. The bottles undergo a process
known as riddling (remuage in French). In this stage, the bottles are placed on special racks called pupitres that hold them at a 45° angle, with the crown cap pointed down. Once a day (every two days for Champagne), the bottles are given a slight shake and turn, alternatively on right then left, and dropped back into the pupitres, with the angle gradually increased. The drop back into the rack causes a slight tap, pushing sediments toward the neck of the bottle. In 10 to 14 days (8 to 10 weeks for Champagne), the position of the bottle is straight down, with the lees settled in the neck. (This time can be shortened by moving the bottle more than once a day, and/or by using modern, less sticky strains of yeast.) Manual riddling is still done for Prestige Cuvées in Champagne, but has otherwise been largely abandoned because of the high labour costs. Mechanised riddling equipment (a gyropalette) is used instead.
Many stores now sell riddling racks for decorative storage of finished wine.


Disgorging



The lees removal process is called disgorging (dégorgement in French), traditionally a skilled manual process where the crown cap and lees are removed without losing much of the liquid, and a varying amount of sugar added. Before the invention of this process by Madame Clicquot in 1816, Champagne was cloudy; this style is seen occasionally today, under the label méthode ancestrale. Modern automated disgorgement is done by freezing a small amount of the liquid in the neck and removing this plug of ice containing the lees.


Dosage



Immediately after disgorging but before final corking, the liquid level is topped up with liqueur d'expédition, commonly a little sugar, a practice known as dosage. The liqueur d'expédition is a mixture of the base wine and sucrose, plus 0.02 to 0.03 grams of sulfur dioxide as a preservative. Some maisons de Champagne (Champagne brands) claim to have secret recipes for this, adding ingredients such as old Champagne wine and candi sugar. In the Traité théorique et pratique du travail des vins (1873), Maumené lists the additional ingredients "usually present in the liqueur d'expédition": port wine, cognac, elderberry wine, kirsch, framboise wine, alum solutions, tartaric acid, and tannins.
The amount of sugar in the liqueur d'expédition determines the sweetness of the Champagne, the sugar previously in the wine having been consumed in the second fermentation. Generally, sugar is added to balance the high acidity of the Champagne, rather than to produce a sweet taste. Brut Champagne will only have a little sugar added, and Champagne called nature or zéro dosage will have no sugar added at all. A cork is then inserted, with a capsule and wire cage securing it in place.
Champagne's sugar content varies. The sweetest level is 'doux' (meaning sweet) and then, in increasing dryness, 'demi-sec' (half-dry), 'sec' (dry), 'extra sec' (extra dry), 'brut' (very dry-dry), 'extra brut' (very dry), 'brut nature/brut zero/ultra brut' (no additional sugar, bone dry).



BOTTLE-FERMENTED

This refers to a wine produced through a second fermentation in a bottle, but (and this is the catch) not necessarily in the bottle in which it is sold. It may have been fermented in one bottle, transferred to a vat and, under pressure at 3°C, filtered into another bottle. This is also known as the “transfer method.”



MÉTHODE RURALE

This refers to the precursor of méthode champenoise, which is still used today, albeit only for a few obscure wines. It involves no second fermentation, the wine being bottled before the first alcoholic fermentation is finished.



CUVE CLOSE, CHARMAT, OR TANK METHOD

This is used for the bulk production of inexpensive sparkling wines that have undergone a second fermentation in large tanks before being filtered and bottled under pressure at -3°C. Contrary to popular belief, there is no evidence to suggest that this is an intrinsically inferior method of making sparkling wine. It is only because it is a bulk production method that it tends to attract mediocre base wines and encourage a quick throughput. I genuinely suspect that a cuve close produced from the finest base wines of Champagne and given the autolytic benefit of at least three years on its lees before bottling might well be
indistinguishable from the “real thing.”



CARBONATION

This is the cheapest method of putting bubbles into wine and simply involves injecting it with carbon dioxide. Because this is the method used to make lemonade, it is incorrectly assumed that the bubbles achieved through carbonation are large and short-lived. They can be, and fully sparkling wines made by this method will indeed be cheapskates, but modern carbonation plants have the ability to induce the tiniest of bubbles, even to the point of imitating the “prickle” of wine bottled sur lie.




FORTIFIED WINES



Any wine, dry or sweet, red or white, to which alcohol has been added is classified as a fortified wine, whatever the inherent differences of vinification may be. Still wines usually have astrength of 8.5 to 15 percent alcohol; fortified wines a strength of 17 to 24 percent. The spirit added is usually, but not always, brandy made from local wines. It is totally neutral, with no hint of a brandy flavor. The amount of alcohol added, and exactly when and how it is added, is as critical to the particular character of a fortified wine as is its grape variety or area of production. Mutage, early fortification, and late fortification are all methods
that may be used to fortify wines.


MUTAGE

This is the addition of alcohol to fresh grape juice. This prevents fermentation and produces fortified wines, known as vins de liqueurs in France, such as Pineau des Charentes in the Cognac region, Floc de Gascogne in Armagnac, and Ratafia in Champagne.


EARLY FORTIFICATION

This is the addition of alcohol after fermentation has begun. This is often done in several small, carefully measured, timed doses spread over several hours or even days. The style of fortified wine being made will dictate exactly when the alcohol is added, and the style itself will be affected by the variable strength of the grapes from year to year. On average, however, alcohol is added to port after the alcohol level has reached 6 to 8 percent, and added to the vins doux naturels of France, such as Muscat de Beaumes de Venise, at any stage between 5 and 10 percent.


LATE FORTIFICATION

This is the addition of alcohol after fermentation has ceased. The classic drink produced by this method is sherry, which is always vinified dry, with any sweetness added afterward.




AROMATIZED WINES



With the exception of Retsina, the resinated Greek wine, aromatized wines are all fortified. They also all have aromatic ingredients added to them. The most important aromatized wine is vermouth, which is made from neutral white wines of 2 to 3 years of age, blended with an extract of wormwood (vermouth is a corruption of the German wermut meaning “wormwood”), vanilla, and various
other herbs and spices. Italian vermouths are produced in Apulia and Sicily, and French vermouths in Languedoc and Roussillon. Chambéry is a delicate generic vermouth from the Savoie and Chambéryzette is a red-pink version flavored with alpine strawberries, but such precise geographical aromatized wines are rare. Most, in fact, are made and sold under internationally recognized brands such as Cinzano and Martini. Other wellknown aromatized wines include Amer Picon, Byrrh, Dubonnet (both red and white), Punt e Mes, St.-Raphael, and Suze.




ICE WINE



Ice wine (or icewine; German Eiswein) 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 concentrated, very sweet wine. With ice wines, the freezing happens before the fermentation, not afterwards. Unlike the grapes from which other dessert wines are made, such as Sauternes, Tokaji, or Trockenbeerenauslese, ice wine grapes should not be affected by Botrytis cinerea or noble rot, at least not to any great degree. Only healthy grapes keep in good shape until the opportunity arises for an ice wine harvest, which in extreme cases can occur after the New Year, on a northern hemisphere calendar. This gives ice wine its characteristic refreshing sweetness balanced by high acidity. When the grapes are free of Botrytis, they are said to come in "clean".
Ice wine production is risky (the frost may not come at all before the grapes rot or are otherwise lost) and requires the availability of a large enough labour force to pick the whole crop within a few hours, on a moment's notice, on the first morning that is cold enough. This results in relatively small amounts of ice wine being made world-wide, making ice wines generally quite expensive.
Ice wine production is obviously limited to that minority of the world's wine-growing regions where the necessary cold temperatures can be expected to be reached with some regularity. Canada and Germany are the world's largest producers of ice wines.




NOBLE ROT



Noble rot -French: pourriture noble; -German: Edelfäule; -Italian: Muffa nobile is the benevolent form of a grey fungus, Botrytis cinerea, affecting wine grapes. Infestation by Botrytis requires moist conditions. If the weather stays wet, the malevolent form, "grey rot," can destroy crops of grapes. Grapes typically become infected with Botrytis when they are ripe. If they are then exposed to drier conditions and become partially raisined this form of infection brought about by the partial drying process is known as noble rot. Grapes when picked at a certain point during infestation can produce particularly fine and concentrated sweet wine. Some of the finest Botrytized wines are literally picked berry by berry in successive tries - French for "selections".
Internationally renowned botrytised wines include the aszú of Tokaj-Hegyalja in Hungary and Slovakia -commonly called Tokaji, Tokajské or Tokay, Sauternes from France - where the process is known as pourriture or pourriture noble, and Beerenauslese or Trockenbeerenauslese wines from Germany and Austria. Other wines of this type include the Romanian Grasă de Cotnari, French Coteaux du Layon, French Monbazillac, Austrian Ausbruch and South African Noble Late Harvest (NLH). Depending on conditions the grapes may be only minimally botrytized. Botrytis has also been imported for use by winemakers in California and Australia. In some cases inoculation occurs when spores are sprayed over the grapes, while some vineyards depend on natural inoculation from spores present in the environment.


Botrytis cinerea



Botrytis cinerea -"botrytis" from Ancient Greek botrys (βότρυς) meaning "grapes" plus the Neolatin suffix -itis for disease, is a necrotrophic fungus that affects many plant species, although its most notable hosts may be wine grapes. In viticulture, it is commonly known as botrytis bunch rot; in horticulture, it is usually called grey mould or gray mold.
The fungus gives rise to two different kinds of infections on grapes. The first, grey rot, is the result of consistently wet or humid conditions, and typically results in the loss of the affected bunches. The second, noble rot, occurs when drier conditions follow wetter, and can result in distinctive sweet dessert wines, such as Sauternes or the Aszú of Tokaji. The species name Botrytis cinerea is derived from the Latin for "grapes like ashes"; although poetic, the "grapes" refers to the bunching of the fungal spores on their conidiophores, and "ashes" just refers to the greyish colour of the spores en masse. The fungus is usually referred to by its anamorph (asexual form) name, because the sexual phase is rarely observed. The teleomorph (sexual form) is an ascomycete, Botryotinia fuckeliana, also known as Botryotinia cinerea.