Sparkling wine production

Last updated

All production methods for sparkling wines have one thing in common: the purpose of introducing enough carbon dioxide in the wine to make it effervescent. Rose Champagne Bubbles.jpg
All production methods for sparkling wines have one thing in common: the purpose of introducing enough carbon dioxide in the wine to make it effervescent.
Champagne bottles in racks in underground cellars Ruttelpult.jpg
Champagne bottles in racks in underground cellars

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.

Contents

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. [1] 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: [2]

Production methods

Yeast in a bottle in riddling (remuage) rack at Schramsberg Vineyards, Napa Schramsberg Vineyards, July 2019-7609.jpg
Yeast in a bottle in riddling (remuage) rack at Schramsberg Vineyards, Napa

Fermentation of sugar into alcohol during winemaking always means that carbon dioxide is released. Carbon dioxide has the property of being very soluble in water (the main constituent of wine), a property that is utilized in sparkling wines. [3] Production always starts from a base wine (where the carbon dioxide from the first fermentation has been gasified). 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 help with appealing aromas to the sparkling wine but look unappetizing. The lees are therefore normally removed before the wine is distributed.

There is some consensus that the methods where the second fermentation occurs in the bottle are usually preferable to the others. [2]

The following table shows the main features of seven main methods used to make sparkling wines. The methods are then described in the text. Within each method there may be variations from one producer to another.

Production stepTraditional methodAncestral methodTransfer methodDioise methodCharmat methodContinuous methodSoda method
Preliminary stagesProduction of base wine and (usually) blending cuvée using normal techniqueYesYesYesYesYesYesYes
Tirage [lower-alpha 1] Yes-Yes-YesYes-
BottlingYesYesYesYes---
Second fermentationIn bottleYesYesYesYes---
In steel tank----YesYes-
Riddling [lower-alpha 2] Yes(Yes) [lower-alpha 3] (Yes) [lower-alpha 4] ----
Disgorging [lower-alpha 5] Yes(Yes) [lower-alpha 3] (Yes) [lower-alpha 4] ----
Emptying, cleaning--YesYes---
Filtering-(Yes) [lower-alpha 3] YesYesYes--
Dosage [lower-alpha 6] Yes-Yes-Yes--
Final stagesAddition of carbon dioxide------Yes
Clarification/filtration--(Yes) [lower-alpha 7] YesYesYes-
CO2 stabilization----YesYesYes
Bottling--YesYesYesYesYes
Corking, labeling, etc.YesYesYesYesYesYesYes

Traditional method

The larger Champagne producers have a number of press houses situated throughout the region, such as this Moet & Chandon facility. Moet&Chandon press house.jpg
The larger Champagne producers have a number of press houses situated throughout the region, such as this Moët & Chandon facility.
Today Gyropalettes usually replace hand power for riddling in the traditional method. Gyropalette Machine.jpg
Today Gyropalettes usually replace hand power for riddling in the traditional method.

The so-called classic way (though not the oldest) to produce sparkling wine is popularly known as the traditional method (French : méthode traditionnelle), or the official EU designation, classic method (méthode classique). In 1994 the designation Champagne method (méthode champenoise) was disallowed as it was too often involved in renommée passing off. [lower-alpha 8] [4] 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. [5]

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 (known as tirage ). The second fermentation results in a natural sparkling wine. Yeast precipitate (lees) must then be removed. This begins with riddling (remuage) 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 (normally a crown cap) 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. [6]

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, some varieties of Sekt and other sparkling wines that have méthode traditionnelle, méthode classique or fermented in this bottle on the label (note, however, that the unusual ancestral and dioise methods also ferment the wine exclusively in the bottle).

Ancestral method

Bugey Cerdon produced with the ancestral method Bugey Cerdon sparkling rose.JPG
Bugey Cerdon produced with the ancestral method

The ancestral method (French : méthode ancestrale) 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. [7] [8] 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 some North American wines. In Italy the name given to a traditional version of the ancestral method is Col Fondo, however producers are increasingly dropping the word from their labels as the name was trademarked in 2002 by two local wineries (as the spelling Colfondo). Although these wineries are not enforcing their trademark rights, they have been unable to come to an agreement with the Consorzio. Under new DOCG law, from 2020 Col Fondo wines will be labelled as Sui Lieviti.

Wines made with the ancestral method are sometimes called pétillant-naturel, popularly abbreviated to pét-nat. Since French wine label regulations ban the word naturel, the appellation from Montlouis-sur-Loire is instead called pétillant originel. [9]

There are two general approaches employed by winemakers to produce pét-nat, the choice of which is often determined by location and weather conditions during harvest as well as the scale of production and resources on hand in the winery when it comes to bottling. The first is the "interruption" method, whereby the primary alcoholic fermentation is interrupted by the act of bottling. The wine goes into bottle, sealed under a crown cap, where the still viable yeast, nutrient and sugar allow the primary fermentation to continue and produce the carbon dioxide that forms the bubbles. Malolactic fermentation may also occur in bottle making a small contribution to the carbon dioxide levels. Unlike the traditional method there is no disgorging and dosage, however producers using the interruption method will often need to remove tartrate crystals and sediment to prevent the wine from gushing when opened as well as to reduce the amount of final sediment to an acceptable level. To accomplish this, the bottles are hand disgorged and topped up with the same wine. The interruption method is often favoured by producers in cooler regions where the fermentation is slower and easier to catch at a specific point and where they have the resources to hand bottle at a specific time and to hand disgorge. The second method is called "entr'acte" (intermission) whereby the primary fermentation is completed to dryness, allowing the wine to be naturally cold stabilised and settled, either in an underground cellar or temperature controlled tank. Sweet juice from a second pick of grapes, often from the same vineyard, is then added to the wine, which is then bottled with the fermentation from the second pick juice completing in bottle to produce the bubbles. The advantages of the entr'acte method is that the wine does not need to be disgorged, there is more control over final sediment and pressure levels leading to an avoidance of gushing. The entr'acte method is often favoured in warmer climates where faster ferments are more difficult to control, as well as where producers want to be more precise with final turbidity and pressure levels as well as minimising overall risk. Alternatively, using a method faithful to the origins of ancestral winemaking, the wine is cold-settled before the end of primary fermentation to mimic the natural changing seasons before being bottled and then allowed to warm up again, as it would in the Spring. This process, a traditional variation on the entr'acte practice, is called the "Overwintering Method," [10] and is how the earliest sparkling wines would have come about, although as an intentional method of production it runs the risk of a stuck ferment.

Styles of pét-nat can very widely, including a range of colours from white, red, pink and orange (not to be confused with skin contact orange wines). Pressure levels can also vary from lightly sparkling (around 1 to 2 bars of pressure), to a gentle foam (around 3 bar) to a full fizz (4 to 5 bars). Common flaws are often related to turbidity and pressure, with wines being barely fizzy to gushing. Common faults are those often associated with low / no sulphur winemaking such as mousiness or excessive levels of brettanomyces or volatile acidity. Due to the fermentation being completed in the bottle, pét-nats can often display funky characteristics, not dissimilar to still natural wines, and which represent a stylistic cross-over with traditional styles of sour beer such as lambics and gueuze. Wines can vary from being highly aromatic to relatively neutral depending on the grape varieties used. They often display relatively low alcohol content, although this is purely a winemaker decision. The wines are sometimes obscure from remaining lees (except those which have been clarified by disgorging). They taste best one to three years after bottling and do not develop with further storage. In general, the wines usually finish fermenting in bottle resulting in them being dry, although there can be some variability with final sugar levels. The method's main challenge is that the production process is difficult to control and therefore requires great skill by the winemaker. The keys to pét-nat production are mastering temperature, timing and turbidity. The volumes produced 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. Visual cues that distinguish pét-nat from other sparkling wines are a sparkling weight bottle, closed with a crown cap, with a wine that is often a little bit cloudy. Pét-nat can be enjoyed as an aperitif or with fruit dishes, however their growing global appeal is as the sparkling wine of choice in the natural wine movement.

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 (six months is the requirement to label a wine 'bottle fermented') then the individual bottles are transferred (hence the name) 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. [11]

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.

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. [5] [12] [13]

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. [14] [15]

Charmat method

Label detail of a French sparkling wine made using the Charmat process Methode Charmat.JPG
Label detail of a French sparkling wine made using the Charmat process

Charmat (Italian : Metodo Martinotti) was developed and patented in 1895 by the Italian Federico Martinotti (1860–1924). [16] The method was further developed with a new patent by the inventor Eugène Charmat in 1907. [17] 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. Fermentation occurs in a closed system, so CO2 cannot directly escape to the atmosphere and dissolves in wine. When the sugar is converted into alcohol and carbon dioxide, the yeast is filtered and removed, and the wine containing the dissolved CO2 is transferred from the close reactor vessel into bottles. The duration of fermentation affects the quality; longer fermentation preserves the wine's aromas better and gives finer and more durable bubbles. [18]

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 variants of Sekt such as Henkell Trocken. Charmat-method sparkling wines can be produced at a considerably lower cost than traditional method wines. [11]

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. [19]

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. [20]

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. [21] 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.' [22]

Wine faults

Several wine faults can occur in sparkling wine production. Some that were present in early production methods include yeux de crapauds (toad's eyes) 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. [23]

Notes

  1. Addition of yeast, nutrients for the yeast, and sugar
  2. Bottles are turned with the neck downwards and lightly shaken to move the lees to the neck of the bottle
  3. 1 2 3 Producer specific variation within the ancestral method
  4. 1 2 Riddling and disgorging only in the transversage variant of the transfer method
  5. The process to remove lees from bottles
  6. Sugar addition
  7. No clarification step after tank storage in the transversage variant of the transfer method, since this has already been taken care of in the riddling and disgorging steps
  8. The term "méthode champenoise" or "Champagne method" was outlawed in Europe in 1994 for all wines other than Champagne (which for obvious reasons does not bother to utilize it), replaced with "traditional method". On labels it may be referred to as "méthode traditionnelle", "méthode classique", "traditional method", "classic method", or the ambiguous term "bottle fermented".

Related Research Articles

<span class="mw-page-title-main">Champagne</span> French sparkling wine

Champagne is a sparkling wine originated and produced in the Champagne wine region of France under the rules of the appellation, which demand specific vineyard practices, sourcing of grapes exclusively from designated places within it, specific grape-pressing methods and secondary fermentation of the wine in the bottle to cause carbonation.

<span class="mw-page-title-main">Sparkling wine</span> Wine with significant levels of carbon dioxide

Sparkling wine is a wine with significant levels of carbon dioxide in it, making it fizzy. While it is common to refer to this as champagne, European Union countries legally reserve that word for products exclusively produced in the Champagne region of France. Sparkling wine is usually either white or rosé, but there are examples of red sparkling wines such as the Italian Brachetto, Bonarda and Lambrusco, and the Australian sparkling Shiraz. The sweetness of sparkling wine can range from very dry brut styles to sweeter doux varieties.

<span class="mw-page-title-main">Winemaking</span> Production of wine

Winemaking or vinification is the production of wine, starting with the selection of the fruit, its fermentation into alcohol, and the bottling of the finished liquid. The history of wine-making stretches over millennia. There are authentic proofs that suggest that the earliest Wine production took place in Georgia and Iran around 6000 to 5000 B.C. The science of wine and winemaking is known as oenology. A winemaker may also be called a vintner. The growing of grapes is viticulture and there are many varieties of grapes.

<span class="mw-page-title-main">Red wine</span> Wine made from dark-colored grape varieties

Red wine is a type of wine made from dark-colored grape varieties. The color of the wine can range from intense violet, typical of young wines, through to brick red for mature wines and brown for older red wines. The juice from most purple grapes is greenish-white, the red color coming from anthocyan pigments present in the skin of the grape. Much of the red wine production process involves extraction of color and flavor components from the grape skin.

<span class="mw-page-title-main">White wine</span> Wine fermented without skin contact

White wine is a wine that is fermented without skin contact. The colour can be straw-yellow, yellow-green, or yellow-gold. It is produced by the alcoholic fermentation of the non-coloured pulp of grapes, which may have a skin of any colour. White wine has existed for at least 4,000 years.

<span class="mw-page-title-main">Malolactic fermentation</span> Process in winemaking

Malolactic conversion is a process in winemaking in which tart-tasting malic acid, naturally present in grape must, is converted to softer-tasting lactic acid. Malolactic fermentation is most often performed as a secondary fermentation shortly after the end of the primary fermentation, but can sometimes run concurrently with it. The process is standard for most red wine production and common for some white grape varieties such as Chardonnay, where it can impart a "buttery" flavor from diacetyl, a byproduct of the reaction.

<span class="mw-page-title-main">Kilju</span> Finnish home made alcoholic beverage

Kilju is the Finnish word for home made alcoholic beverage typically made of sugar, yeast, and water.

<span class="mw-page-title-main">Asti wine</span> Italian sparkling white wine

Asti is a sparkling white Italian wine that is produced throughout southeastern Piedmont, but is particularly focused around the towns of Asti and Alba. Since 1993 the wine has been classified as a denominazione di origine controllata e garantita (DOCG) and as of 2004 was Italy's largest producing appellation. On an average vintage more than ten times as much Asti is produced in Piedmont than the more well-known Piedmontese red wine Barolo.

Secondary fermentation is a process commonly associated with winemaking, which entails a second period of fermentation in a different vessel than the one used to start the fermentation process. An example of this would be starting fermentation in a carboy or stainless steel tank and then moving it over to oak barrels. Rather than being a separate, second fermentation, this is most often one single fermentation period that is conducted in multiple vessels. However, the term does also apply to procedures that could be described as a second and distinct fermentation period.

The glossary of wine terms lists the definitions of many general terms used within the wine industry. For terms specific to viticulture, winemaking, grape varieties, and wine tasting, see the topic specific list in the "See also" section below.

<span class="mw-page-title-main">Outline of wine</span> Overview of and topical guide to wine

The following outline is provided as an overview of and topical guide to wine:

<span class="mw-page-title-main">Traditional method</span> Champagne production method

The traditional method is the process used in the Champagne region of France to produce Champagne. It is also the method used in various French regions to produce sparkling wines, in Spain to produce cava, in Portugal to produce Espumante and in Italy to produce Franciacorta. The method is known as the méthode champenoise, but the Champagne producers have successfully lobbied the European Union to restrict the use of that term within the EU only to wines produced in Champagne. Thus, wines from elsewhere cannot use the term "méthode champenoise" on products sold in the EU, and instead the term "traditional method" or the local language equivalent. South African wines from the Western Cape are labelled with the term Methode Cap Classique. Some wine producers in countries outside the EU may disregard EU labeling laws and use méthode champenoise or even "Champagne" on labels for products not exported to the EU, but this usage is decreasing.

<span class="mw-page-title-main">Limoux wine</span>

Limoux wine is produced around the city of Limoux in Languedoc in southwestern France. Limoux wine is produced under four Appellation d'origine contrôlée (AOC) designations: Blanquette de Limoux, Blanquette méthode ancestrale, Crémant de Limoux and Limoux, the first three of which are sparkling wines and dominate the production around Limoux. The main grape of the region is the Mauzac, locally known as Blanquette, followed by Chardonnay and Chenin blanc. In 2005, the Limoux AOC was created to include red wine production consisting of mostly Merlot. Wine historians believe that the world's first sparkling wine was produced in this region in 1531, by the monks at the abbey in Saint-Hilaire.

The classification of wine is based on various criteria including place of origin or appellation, vinification method and style, sweetness and vintage, and the grape variety or varieties used. Practices vary in different countries and regions of origin, and many practices have varied over time. Some classifications enjoy official protection by being part of the wine law in their country of origin, while others have been created by, for example, growers' organizations without such protection.

<span class="mw-page-title-main">Fermentation in winemaking</span> Wine making process

The process of fermentation in winemaking turns grape juice into an alcoholic beverage. During fermentation, yeasts transform sugars present in the juice into ethanol and carbon dioxide. In winemaking, the temperature and speed of fermentation are important considerations as well as the levels of oxygen present in the must at the start of the fermentation. The risk of stuck fermentation and the development of several wine faults can also occur during this stage, which can last anywhere from 5 to 14 days for primary fermentation and potentially another 5 to 10 days for a secondary fermentation. Fermentation may be done in stainless steel tanks, which is common with many white wines like Riesling, in an open wooden vat, inside a wine barrel and inside the wine bottle itself as in the production of many sparkling wines.

<span class="mw-page-title-main">Cider</span> Fermented alcoholic beverage from apple juice

Cider is an alcoholic beverage made from the fermented juice of apples. Cider is widely available in the United Kingdom and the Republic of Ireland. The UK has the world's highest per capita consumption, as well as the largest cider-producing companies. Ciders from the South West of England are generally higher in alcoholic content. Cider is also popular in many Commonwealth countries, such as India, South Africa, Canada, Australia, and New Zealand. As well as the UK and its former colonies, cider is popular in Portugal, France, Friuli, and northern Spain. Germany also has its own types of cider with Rhineland-Palatinate and Hesse producing a particularly tart version known as Apfelwein. In the U.S. and Canada, varieties of alcoholic cider are often called hard cider to distinguish it from non-alcoholic apple cider or "sweet cider", also made from apples. In Canada, cider cannot contain less than 2.5% or over 13% absolute alcohol by volume.

<span class="mw-page-title-main">History of Champagne</span>

The history of Champagne began when the Romans planted vineyards in this region of northeast France in the 5th century, or possibly earlier. Over centuries, Champagne evolved from being a pale, pinkish still wine to a sparkling wine. When Hugh Capet was crowned King of France in 987 at the cathedral of Reims, he started a tradition that brought successive monarchs to the region—with the local wine being on prominent display at the coronation banquets. The early wine of the Champagne region was a pale, pinkish wine made from Pinot noir.

This glossary of winemaking terms lists some of terms and definitions involved in making wine, fruit wine, and mead.

<span class="mw-page-title-main">Autolysis (alcohol fermentation)</span>

Autolysis in winemaking relates to the complex chemical reactions that take place when a wine spends time in contact with the lees, or dead yeast cells, after fermentation. While for some wines - and all beers - autolysis is undesirable, it is a vital component in shaping the flavors and mouth feel associated with premium Champagne production. The practice of leaving a wine to age on its lees has a long history in winemaking dating back to Roman winemaking. The chemical process and details of autolysis were not originally understood scientifically, but the positive effects such as a creamy mouthfeel, breadlike and floral aromas, and reduced astringency were noticed early in the history of wine.

<span class="mw-page-title-main">Yeast in winemaking</span> Yeasts used for alcoholic fermentation of wine

The role of yeast in winemaking is the most important element that distinguishes wine from fruit juice. In the absence of oxygen, yeast converts the sugars of the fruit into alcohol and carbon dioxide through the process of fermentation. The more sugars in the grapes, the higher the potential alcohol level of the wine if the yeast are allowed to carry out fermentation to dryness. Sometimes winemakers will stop fermentation early in order to leave some residual sugars and sweetness in the wine such as with dessert wines. This can be achieved by dropping fermentation temperatures to the point where the yeast are inactive, sterile filtering the wine to remove the yeast or fortification with brandy or neutral spirits to kill off the yeast cells. If fermentation is unintentionally stopped, such as when the yeasts become exhausted of available nutrients and the wine has not yet reached dryness, this is considered a stuck fermentation.

References

  1. Elliot Essman. "Wine Language - The Many Degrees of Fizz". Style Gourmet. Archived from the original on 21 June 2016. Retrieved 21 June 2016.
  2. 1 2 "A Sparkling Success World-Wide: An Example to Reflect On". Effervescents du Monde. Archived from the original on 15 February 2016. Retrieved 17 May 2016.
  3. "How Sparkling Wine is Made". Wine Folly. Retrieved 7 March 2023.
  4. Jancis Robinson, ed. (1999). Oxford Companion to Wine (Second ed.). Oxford University Press. ISBN   019866236X.
  5. 1 2 "Sparkling Wine Production Methods". Champagne411. Archived from the original on 29 May 2016. Retrieved 29 May 2016.
  6. "Méthode Champenoise or Traditional Method". Effervescents du Monde. Archived from the original on 10 March 2014. Retrieved 17 May 2016.
  7. McCarthy, Ed; Ewing-Mulligan, M. (2001). French Wine for Dummies. Wiley Publishing. p.  222. ISBN   0-7645-5354-2.
  8. "Method Ancestral - Sparkling Wines Produced by Spontaneous Fermentation". Effervescents du Monde. Archived from the original on 25 November 2013. Retrieved 29 May 2016.
  9. Zachary Sussman (26 May 2015). "What Is "Pét-Nat," Really?". Punch. Archived from the original on 29 May 2016. Retrieved 29 May 2016.
  10. "Blog". Stardust Cellars. Retrieved 16 January 2021.
  11. 1 2 J. Robinson, ed. (2006). The Oxford Companion to Wine (Third ed.). Oxford University Press. pp.  657–660. ISBN   0-19-860990-6.
  12. "Method Transfer". Effervescents du Monde. Archived from the original on 25 November 2013. Retrieved 17 May 2016.
  13. "Sparkling Wine". Wine Guide by Virgin Wines. Archived from the original on 24 May 2016. Retrieved 24 May 2016.
  14. "Our Clairette de Die Tradition AOC "Cuvée Chambéran"". Union des Jeunes viticulteurs Récoltants. Archived from the original on 12 October 2007. Retrieved 17 May 2016.
  15. "Method Dioise / Asti Spumante". Effervescents du Monde. Archived from the original on 25 November 2013. Retrieved 17 May 2016.
  16. Patent CH-10711 granted 12 July 1895: Installation pour la fabrication continue des vins mousseux.
  17. Patent GB-7734 granted 7 April 1908, with French priority 17 April 1907: Process for Decanting Sparkling Wines.
  18. "Method Closed Tank". Effervescents du Monde. Archived from the original on 25 November 2013. Retrieved 17 May 2016.
  19. "Method Continuous or Russian Method". Effervescents du Monde. Archived from the original on 22 September 2015. Retrieved 17 May 2016.
  20. J. Robinson, ed. (2006). The Oxford Companion to Wine (Third ed.). Oxford University Press. pp.  659. ISBN   0-19-860990-6.
  21. "Method Carbonation". Effervescents du Monde. Archived from the original on 25 November 2013. Retrieved 17 May 2016.
  22. "Presentation and labelling of wine and certain wine products". Export Helpdesk. European Commission. Retrieved 17 May 2016.
  23. D. & P. Kladstrup (2005). Champagne. Harper Collins Publisher. p.  45. ISBN   0-06-073792-1.