Sparkling wine

In simple terms, the generic term sparkling wine refers to wines that have been enriched or supersaturated with carbonic acid (or carbon dioxide; CO2) and therefore have an overpressure of at least 3 bar at 20 °C .

Sparkling wine can be produced by the carbon dioxide from its natural fermentation or by pumped-in (foreign) carbon dioxide. If the excess carbon dioxide pressure in the bottle is only very low due to the production process (at least 1.0 to 2.5 bar at 20 °C), the wine only bubbles slightly in the glass and is referred to as a 'sparkling wine'. Sparkling wine is not a sparkling wine, but is only considered a 'table wine' in terms of quality.

Sparkling wine was not invented, but is rather a freak of nature. Sparkling wines are not only made from grape juice, but also from a variety of other fruits. These are often grouped together as 'sparkling wine-like drinks'.

Almost every wine has 'bubbled' more or less naturally at some point in its development. When yeasts in grape juice or 'must' encounter sugar, they will convert this sugar into alcohol and carbon dioxide at an appropriate temperature. During this so-called fermentation, every must bubbles to a greater or lesser extent. Normally, however, the carbon dioxide disappears during fermentation almost as quickly as it is produced. As soon as the yeasts no longer process sugar, the must no longer bubbles. As a result, this alcoholic must is commonly referred to as (still) wine. The 'trick' in the production of sparkling wine is therefore not the formation of carbon dioxide, but rather the successful 'locking in' of the carbon dioxide in a wine bottle. This is achieved using three methods:

1) The oldest method of producing sparkling wine is known as the rural method or méthode rurale. Here, the must ferments partially or completely in closed containers - based solely on the grape sugar present in the original vines.

In this method, the must ferments only once (as in the production of conventional wines). This fermentation can either take place completely in pressure-resistant containers or be interrupted by cool temperatures. While the yeast rests temporarily in the cool must during interrupted fermentation, this still incompletely fermented must can be transferred to bottles, which are then sealed tightly with corks (crown or natural corks). The same yeasts then continue fermentation with the remaining sugar at warmer temperatures in the bottles. Once the process is complete, the yeast sediment is removed from the bottles (by disgorging) or the pressure vessels (by filtering). In general, the same bottles are then sealed tightly with natural corks during bottle fermentation. The sparkling wine from the pressure tanks is bottled and also sealed with natural corks.

Sparkling wines that are fermented using only the natural grape sugar from the vines are also known as natural sparkling wines. The famous Asti Spumante is a classic in this group of sparkling wines. There is also the Blanquette de Limoux and the Clairette de Die.

Over the course of time, cellar masters often added sugar to the must in a more or less qualified manner in order to produce more carbon dioxide during fermentation. The perfection of this type of sparkling wine production (which was not just about 'more carbon dioxide') originated in Champagne. As a result, the method practiced there became known worldwide as the méthode champenois. Until the 1980s, this modification of the classic méthode rurale was often still used in the production of champagne and sparkling wine. Sometimes the extension or continuation of the first fermentation (secondary fermentation) by adding sugar to promote the formation of carbon dioxide in pressure-resistant containers is also referred to as 'second fermentation'. However, it is only since the successful cultivation of special yeasts (so-called pure yeasts; 1894 in Geisenheim/Germany, 1895 in Epernay/France) that we can speak of a second fermentation in the production of sparkling wine or champagne at today's level.

2. in the second method, the must is not partially or completely fermented in pressure-resistant containers, but a finished (still) wine is stimulated to ferment again by adding sugar and pure yeast. This is referred to as the second fermentation. In simple terms, one could also say that talented cellar masters allow their already finished wines to produce carbon dioxide again by adding sugar and special yeast. This second fermentation of the wines (or wine blends) must be carried out in pressurized containers (large-capacity fermentation) or in sealed bottles (bottle fermentation) so that the carbon dioxide does not evaporate. The second fermentation can in turn be realized by three different methods:

2a. Charmat process, large-capacity fermentation (méthode charmat)
Named after the French scientist Eugene Charmat, this process involves large-capacity fermentation in large stainless steel pressure tanks. Some of these air-conditioned tanks hold 100,000 to 200,000 liters of wine. The wine is brought to a second fermentation by adding sugar and cultured yeasts. The resulting carbon dioxide remains trapped in the pressure tank and transforms the wine into sparkling wine. As the yeasts give the sparkling wine further precious flavors after they die off, the yeast sediment in the tank is periodically stirred up by powerful agitators. In the case of German sparkling wine, for example, the sparkling wine spends at least six months with the yeast sediment in the tank. The dosage, which gives the sparkling wine the desired residual sweetness, can also be mixed very evenly into the enormous quantity of sparkling wine. Finally, the tank is cooled down to minus degrees. At this temperature, the carbon dioxide in the sparkling wine becomes 'inactive' and is therefore bound in the sparkling wine. The sparkling wine can now be filtered and bottled. Of the more than 1.5 billion bottles of various sparkling wines from all over the world, the majority are produced using the Charmat process. Almost every German sparkling wine is also produced in this way.

2.b. Transvasier procedure
The name for this process is derived from the French word transvaser, which means 'to decant' or 'to pour'. The transvasier process is a fully automated type of 'bottle fermentation'. The second fermentation of the wines takes place in many bottles as part of a large closed system. After the wine has completed its second fermentation in the bottles (often magnum bottles that can be used several times), it is transferred to large pressure tanks under counterpressure. It can then be flavored and filtered with sugar (similar to the Charmat process). It is then filled into (new) bottles. The reader might rightly ask why the Charmat process was not used to produce the sparkling wine. The reason could be hidden in the word 'bottle fermentation', as German legislation allows this term to be used on the label for sparkling wines of this type. To the connoisseur, the word 'bottle fermentation' probably suggests 'added value' and 'tradition', which should result in a higher price.

2.c. Traditional bottle fermentation, classic bottle fermentation process
Sparkling wines of this type are produced in a similar (sometimes exact) way to champagne. The second fermentation takes place in individual bottles. The sparkling wines are then stored 'on the lees' for a long time, shaken by hand or by machine, then disgorged, sometimes with a dosage, sealed with natural corks and delivered. In the past, this process was generally referred to as méthode champenois in the EC. Later, this designation was legally restricted to products from Champagne. In some other countries outside the EC, however, this designation still exists today. This process produces the most elaborate and best sparkling wines in the world. Champagne has long been considered the undisputed king of this class, but there are sometimes other excellent sparkling wines from different countries. For example, there are certain vintners' sparkling wines that can simply be described as outstanding.

3. the third method does not actually deserve to be called a 'method', as it merely involves impregnation with carbon dioxide or the subsequent pumping of foreign carbon dioxide into a wine. Ultimately, the end product is more of a kind of 'sparkling wine', which may also be called 'sparkling wine', but in some countries (such as Germany) must be labeled as 'sparkling wine with added carbon dioxide'. Wine connoisseurs often consider sparkling wines of this type to be 'bottom drawer' in terms of quality.

Speaking of 'quality', not every sparkling wine can be described as a 'quality sparkling wine'. With at least half a dozen other sparkling wine qualifications, the legislator has ensured that connoisseurs cannot be misled by producers about the quality of the sparkling wines produced. Unfortunately, as is so often the case with 'complex simplifications', the majority of connoisseurs do not understand the information (more or less noted on the label).

As noted, sparkling wine is not necessarily a quality sparkling wine. Sparkling wine is a quality sparkling wine, but not necessarily a 'Q.b.A' or quality sparkling wine from a specific growing region (Sekt b.A.). Cava, on the other hand, is a quality sparkling wine, but is generally referred to as 'cava' rather than 'sparkling wine'. Then there is also the so-called 'aromatic quality sparkling wine'. This quality sparkling wine may only be made from qualified 'bouquet grape varieties' (e.g. Gewürztraminer, Muscat varieties, Scheurebe and Huxelrebe). Although other quality sparkling wines should generally be at least 3.5 bar pressure, only 3 bar pressure is required for 'aromatic quality sparkling wine'. However, the 'aromatic quality sparkling wine' is a quality sparkling wine, which in turn may not be called sparkling wine. There is also an exception rule where standard quality sparkling wines (Sekt) in quarter bottles only have to have a carbon dioxide overpressure of at least 3.0 bar instead of 3.5 bar. Sparkling wine is not only made from grapes, but also from many other fruits. However, these sparkling wines are not 'officially' sparkling wines, but rather 'fruit sparkling wines' or the fruit must be noted (e.g. 'apple sparkling wine'). Bottle fermentation' is also not the same as bottle fermentation. A distinction is made between 'bottle fermentation' and 'bottle fermentation according to the traditional method'.

It is therefore understandable that many sparkling wine connoisseurs, who simply want the superlative among sparkling wines, go straight for champagne.

The history of sparkling wine

If anyone should be credited with the 'invention' of sparkling wine, then the credit clearly goes to some resourceful Benedictine monks from the Aude valley in the south of France.

As early as 1540, these monks at Saint-Hilaire Abbey in Limoux deliberately bottled incompletely fermented wines in the cool of autumn, corked them with the then newly discovered oak corks and secured the corks to the neck of the bottle with strings. In the warm spring, the wine continued to ferment and the carbon dioxide was trapped in the bottles: The first sparkling wines were born!

This 'original method' of sparkling wine production is known as the méthode ancestrale. At the time of this méthode ancestrale, however, there was no process for properly removing the lees from the bottles. As a result, the sparkling wine was rather cloudy and the lees found their way into the glass. These original sparkling wines later became known as Blanquette wines. Today's well-known Blanquette de Limoux sparkling wines are 95% produced using more modern methods. However, the winegrowers still make the remaining 5% of their sparkling wines just like the resourceful monks in the style of the 16th century.

Sparkling wines were created in a similar way in England in the 17th century, which could actually also be described as 'original champagne':

Winegrowers in Champagne fermented their wines as much as possible before delivery, but sometimes not completely. In Champagne, cool autumnal weather often set in during the wine-making process, which meant that the yeasts went into a kind of 'hibernation' before fermentation was complete. In spring, the wine was then exported to England in barrels. Once in England, the yeasts suddenly perked up again in the warmer spring weather. The bottled and corked wines were then already modest sparkling wines that caused great enthusiasm at the English royal court (see also Saint Evremond).

As early as 1662, Dr. Christopher Merret documented at the Royal Society of England that wine merchants apparently added "sugar and molasses" to various wines to promote foaming. In 1676, Sir George Etherege even spoke of a 'foaming champagne'.

In addition, the technology for producing high-quality, sturdy bottles (verre anglais) already existed in England. These robust bottles could withstand the carbon dioxide pressure far better than conventional bottles from France.

Oak corks had also long been available thanks to England's lively trade with Portugal. In Champagne, however, leaky wooden stoppers and inadequate bottles were still widely used. In addition, although winegrowers in Champagne were aware of the subsequent effervescence of some of their wines in the spring, this was by no means a source of enthusiasm, but rather annoyed the winegrowers: effervescent wine was regarded as faulty, inferior and unripe. Such wine was then regularly referred to as vin du diable (devil's wine). It was not until 20 to 30 years later that stronger bottles and oak corks slowly became established in Champagne. In addition, some winegrowers in Champagne realized that their 'vin du diable' was highly revered elsewhere as 'vin mousseaux'. As a result, more attention was paid to the preservation and promotion of carbonic acid in Champagne.

Over time, resourceful winegrowers and monks in Champagne refined the process of fermentation in the bottle, among other things. Until around 1730, however, sparkling wine was merely a product of natural secondary fermentation in the bottle. After that, the wine was increasingly bottled at earlier stages of the first fermentation in order to give the wine even more carbon dioxide in the bottles. Bottle breakage was no longer a rarity.

In addition to the increasing pressure in the Champagne bottles, Champagne houses were simultaneously facing a completely different kind of pressure: competition from abroad! It was now internationally known that sparkling wine from Champagne enjoyed great popularity. Shortly after the Napoleonic Wars, Champagne had already become a symbol of sparkling wine. Countries such as Germany, Austria, Italy, Switzerland, Hungary and Russia also produced large quantities of sparkling wine in the 19th century.

In addition, every sparkling wine, regardless of its origin, was generally referred to as 'champagne' as a matter of course in German-speaking countries. Virtually no one knew the term 'sparkling wine', although a Mr. J. G. Herder from Germany had already added a loan translation of the French 'vin mousseux' to the German vocabulary in 1779: 'Schaumwein'. It was not until 1876 that a German dictionary confirmed the term 'sparkling wine'. Until the Treaty of Versailles (1919), no law prohibited German sparkling wine producers from calling their sparkling wine 'Champagne'.

The major breakthrough for sparkling wine from Champagne came around 1800 with a decree issued by the French minister Antoine Chaptal (see also Chaptalization). From then on, it was permitted by law to add sugar to wines that naturally contained relatively little sugar during fermentation.

For the winegrowers of Champagne in particular, the permission to add sugar afterwards was extremely advantageous, as the environmental conditions of this northern, cool winegrowing region were rarely able to introduce enough natural grape sugar into the vines.

This new regulation actually referred to the addition of sugar to the must before the first fermentation. Soon after, however, cellar masters also added sugar to their wines immediately before bottling; this addition was called prise de mousse and resulted in fantastic effervescence. Shockingly, however, up to 80% of the bottles exploded in the cellars of the champagne houses. From a scientific point of view, it was not known how much sugar was right for the secondary fermentation in the bottles. This dreaded phenomenon was known at the time as casse. The enormous percentage of broken bottles also resulted in considerable price increases. As a result, only the rich could afford the remaining champagne. This also gave rise to the description of champagne (and later sparkling wine) as a 'luxury drink'.

Until this time, the unsightly dead yeast in the bottles (lees) could only be removed from the sparkling wine with great difficulty. Champagne bottles were initially placed upside down in a sandpit to move the dead yeast into the neck of the bottle. Around 1818, the famous widow Clicquot invented the riddling console together with the cellar master Antoine Müller. Since then, shaking the bottles to remove the lees has been perfected.

As early as 1815, the French scientist Louis-Joseph Gay-Lussac presented the following theory: "One molecule of sugar releases two molecules of ethyl alcohol and two molecules of carbonic acid and heat". Although groundbreaking, the new findings were unfortunately rather irrelevant in the practice of champagne production. It was not until 1836 that a French pharmacist developed a formula that reliably determined the appropriate amount of added sugar for the desired formation of carbon dioxide in the bottles (see also Réduction François).
In 1860, the famous French scientist Louis Pasteur proved that the original formula of the reaction during fermentation only applies to approx. 95% of the converted sugar, while the remaining approx. 5% are in turn dependent on important secondary substances such as (among others) glycerine, higher alcohols and certain acids.

By 1880, only around 5-6% of champagne and sparkling wine production was still affected by bottle breakage. Although the reason for the designation as a luxury drink had now been eliminated and champagne and sparkling wine were now often cheaper than other quality wines, the state's maintenance of this qualification as an 'object of luxury enjoyment' was a very convenient pretext for the considerable taxation of sparkling wines to this day. In 2003, the German tax on sparkling wine brought 432.3 million euros into the state coffers.

Until the 1970s, it was largely just a sugar-enhanced continuation of the first fermentation of still young (one-year-old) wines with remaining (still viable) yeast (or the temporary addition of lees from another wine fermentation) in bottles. The méthode champenois was ultimately nothing more than an extension of the original méthode rural. It was not until the 1980s that the addition of a highly-qualified mixture of wine, sugar and special yeast (liqueur de tirage) for the purpose of a second fermentation began to gain acceptance among Champagne houses. Only since the successful cultivation of pure yeasts (1894 in Geisenheim, 1895 in Epernay) has it been possible to speak of champagne or sparkling wine production in the modern sense. Scientists carefully isolated certain yeast strains from particularly good wines. To this day, they are known as champagne yeasts or sparkling wine yeasts. These yeasts are characterized by high alcohol and glycerine production and are ideal for the production of sparkling wines, which are produced by a second fermentation of already fermented wines. At high alcohol levels, considerable carbon dioxide pressure and cool temperatures, these cultured yeasts continue to ferment where many other yeast varieties have long since failed or died. In addition, cultured yeasts form a grainy, easier to shake sediment after dying and at the same time give the sparkling wine special aromatic qualities.

In the meantime, the French scientists Jaunay and Maumené had successfully experimented with a pressure-resistant large container for fermenting wines in 1852. As early as 1888, the 'Deutsche Schaumweinfabrik in Wachenheim' was founded in Germany, which used so-called large-capacity fermentation. In 1910, the Frenchman Eugene Charmat developed an exemplary pressure tank process for the automatic production of large quantities of sparkling wine. His process suddenly changed the sparkling wine industry in Europe: by 1930, over five million bottles of sparkling wine were already being produced using the 'Charmat process' in France alone.

By 1910, clearly different directions were already emerging in the sparkling wine industry. While other regions in France and the rest of the world were increasingly turning to 'progressive methods' in the sense of making sparkling wines cheaper through large-scale fermentation, quantity, abbreviated fermentation processes and impregnated sparkling wines, Champagne remained strictly true to its tradition of elaborate bottle fermentation and top quality (rather than quantity). Champagnes were already well known around the world as the non plus ultra. In addition, many prominent and influential champagne houses had long since emerged. In neighboring Germany in particular, however, large-scale fermentation for the production of sparkling wine was gaining a foothold. Traditional (bottle-fermented) sparkling wines were also fighting for market share. Similarly, very inexpensive impregnated sparkling wines were now successfully participating in the market.

The Charmat process was perfected in Germany after the Second World War. For many decades, the majority of sparkling wines around the world have been produced using large-capacity fermentation.

However, there is no doubt among wine connoisseurs that the elaborate traditional bottle fermentation of Champagne (and some other sparkling wines) produces a much higher quality sparkling wine. In return, however, the 'other' sparkling wines of the Charmat method are considerably cheaper.

Quality has its price.