Sparkling wine production


Sparkling wine production is the method of winemaking used to produce sparkling wine. The oldest known production of sparkling wine took place in 1531 with the ancestral method.

Pressure and terminology

In popular parlance and also in the title of this article the term sparkling is used for all wines that produce bubbles at the surface after opening. Under EU law the term sparkling has a special meaning that does not include all wines that produce bubbles. For this reason the terms fizzy and effervescent are sometimes used to include all bubbly wines.
The following terms are increasingly used to designate different bottle pressures:
of sugar into alcohol during winemaking always means that carbon dioxide is released. Carbon dioxide has the property of being very soluble in water, a property that is utilized in sparkling wines. Production always starts from a base wine. In Champagne production, the base wine is usually a blend of wines from different grape varieties and different wineries, where the distribution gives the final wine its special character, called cuvée. In some commonly used methods the base wine undergoes a secondary fermentation, which encloses the resulting carbon dioxide under excess pressure and binds it to the liquid in the sparkling wine. In this way the carbon dioxide content is created which, after opening the bottle, produces the bubbles. The dead yeast cells form a precipitate called lees, that often helps with appealing aromas to the sparkling wine but looks unappetizing. The lees is therefore normally removed before the wine is distributed.
The main methods used to make sparkling wines are often given as seven, with some variations. What or which production methods that give the best wines is not a moot point, but there is some consensus that the first four methods, where the second fermentation occurs in the bottle, are usually preferable to the latter three. The following table shows the main features of each method. The methods are then described in the text. Within each method there may be variations from one producer to another.

Traditional method

The so-called classic way to produce sparkling wine is popularly known as the traditional method, or the official EU designation, classic method. In 1994 the designation Champagne method was disallowed as it was too often involved in renommée passing off. As the former designation suggests, the method is used for the production of most Champagne, and it is slightly more expensive than the Charmat method. Champagne in bottles of 375 ml, 750 ml and 1.5 liters must be produced with the traditional method, but smaller and larger bottles are usually produced with the transfer method.
The wine is fermented once in the barrel and then undergoes a second fermentation in the bottle after the addition of yeast, nutrients for the yeast, and sugar. The second fermentation results in a natural sparkling wine. Yeast precipitate must then be removed. This begins with riddling which means that the bottles are turned with the neck downwards and lightly shaken to move the lees to the neck of the bottle. This is done in small steps where the bottle orientation gradually changes. Finally the inverted bottle necks are cooled so that the precipitation freezes to a small block of ice, the bottles are turned upright and the temporary closure is opened so that the precipitate is pushed out by the pressure in the bottle. Then the bottle is filled to replace the missing volume, and fitted with a plain Champagne cork and halter. The process to remove lees is called disgorging.
Historically the various stages were performed manually but the whole process is now automated for most wines. In connection with the filling of the missing volume, it is common to add a certain amount of sugar dissolved in wine to give the sparkling wine a smoother taste. Sugar addition is called dosage and the added liquid liqueur d'expedition.
In many cases the wine is stored on the lees – sur lie – under carbon dioxide pressure for a long time before disgorging takes place, to get a more mature character. The requirement for non-vintage Champagne is at least 15 months of storage on the lees, and for vintage Champagne at least three years.
The traditional method is used for Champagne, all European wines with the designation Crémant, Cava, better varieties of Sekt and other sparkling wines that have méthode traditionnelle, méthode classique or fermented in this bottle on the label.

Ancestral method

The ancestral method goes under many local names in the various French regions, such as rurale, artisanale and gaillacoise. This is by far the oldest method of making sparkling wine and preceded the traditional method by almost 200 years, or possibly even more. The wine that is now called Blanquette de Limoux is considered by wine historians to be the world's first sparkling wine, and was produced in Limoux in 1531 by monks in the monastery of Saint-Hilaire. Wines produced using the ancestral method include among others French wines from Gaillac, Bugey Cerdon and Blanquette de Limoux, German wines from a few vineyards where the method is usually called méthode rural, and North American wines.
Wines made with the ancestral method are sometimes called pétillant-naturel, popularly abbreviated to pét-nat. Since French wine labels ban the word naturel the appellation from Montlouis-sur-Loire is instead called pétillant originel.
Alcoholic fermentation is not completely finished when the wine is bottled. It follows that the carbon dioxide is produced by the fermenting yeasts, and where malolactic fermentation has not yet taken place. Unlike the traditional method there is no disgorging and dosage, but the wine is normally filtered. To accomplish this the bottles are emptied, then cleaned and refilled.
The method generally produces wines that are highly aromatic with low alcohol content, sometimes as low as 6%. The wines are sometimes somewhat obscure from remaining lees. They taste best 1–3 years after bottling and do not develop with further storage. In general, the wines are slightly sweet but brut varieties are also produced. The method's main weakness is that the production process is difficult to control and therefore requires great skill by the winemaker. The produced volumes are very modest. High-quality wines produced with the ancestral method, often by small growers using organic farming principles, can be complex and very distinctive. They are mainly used as aperitifs or dessert wine with fruit dishes.

Transfer method

The transfer method follows the first steps of the traditional method in that after primary fermentation the cuvée is transferred to bottles to complete secondary fermentation, which allows for additional complexity. When the secondary fermentation is complete and the wine has spent the desired amount of time in bottle on yeast lees then the individual bottles are transferred into a larger tank. The wine is then filtered, liqueur de dosage added, and then filled back into new bottles for sale. This method allows for complexity to be built into the wine, but also gives scope for blending options after the wine has gone into bottle and reduces the bottle-to-bottle variations that can be hard to control in the traditional method.
The name transversage method is often used as a synonym to transfer method, but is actually a slight twist to the latter. In the transfer method proper, the wine is transferred to a tank directly after ageing on lees, while in the transversage method, the wine is riddled and disgorged before transfer to a tank. Consequently the transversage method doesn't need additional clarification before bottling.
The transfer method gives better results than the charmat method, particularly in terms of bubble size and durability. Sparkling wines from New Zealand and Australia often use the transfer method. The method is used for sparkling wine sold in unusually small or unusually large bottles.

Dioise method

This method is used for Clairette de Die AOC where the method is officially designated as the original dioise process. In contrast to the ancestral method the yeast production is controlled by cooling. The dioise method is used in among others the Drôme valley in France, as well as for Asti Spumante produced in Canelli in the Piedmont region in Italy.

Charmat method

Charmat was developed and patented in 1895 by the Italian Federico Martinotti. The method was further developed with a new patent by the inventor Eugène Charmat in 1907. The method is now named after the latter, but is also called cuve close, metodo Italiano or the tank method. The wine is mixed in a stainless steel pressure tank, together with sugar and yeast. When the sugar is converted into alcohol and carbon dioxide, the yeast is filtered and removed, and the wine is bottled. The duration of fermentation affects the quality; longer fermentation preserves the wine's aromas better and gives finer and more durable bubbles.
This production method is widely used in the U.S., in Italy, especially in the Asti province, and in Prosecco wines, and in Germany to produce cheap variants of Sekt. Charmat-method sparkling wines can be produced at a considerably lower cost than traditional method wines.

Continuous method

The continuous method is also called the Russian method. The secondary fermentation takes place in steel tanks with special rings, or with added oak chips. The wine circulates slowly and becomes reasonably clear before it is bottled.
Sovetskoye Shampanskoye, Soviet Champagne, or under European Union law Soviet sparkling wine, is produced by the continuous method in Russia and former Soviet Union countries. In 1975 Moët & Chandon bought a licence for production of sparkling wine by the continuous method.

Soda method

Simpler, cheaper sparkling wines are manufactured simply by adding CO2 to the wine from a carbonator. The bubbles created by using this method will be relatively large and volatile. In the European Union sparkling wines made via this method must use terms 'aerated sparkling wine' and 'aerated semi-sparkling wine', supplemented where necessary with the words 'obtained by adding carbon dioxide' or 'obtained by adding carbon anhydride.'

Wine faults

Several wine faults can occur in sparkling wine production. Some that were present in early production methods include yeux de crapauds which was a condition of big, viscous bubbles that resulted from the wine spending too much time in wooden casks. Another fault could occur when the wine is exposed to bacteria or direct sunlight, leaving the wine with murky colouring and an oily texture.