Process in the production of sparkling wine or semi-sparkling wine in which the second fermentation does not take place in the bottle but in a pressure tank. This is why it is also known as tank fermentation or bulk fermentation, in France as Cuve-close and in Spain as Granvás. The invention is attributed to the French agricultural engineer Eugène Charmat. He experimented with pressure tanks at the beginning of the 20th century at the University of Montpellier (Languedoc) and introduced the method in 1910. Especially in Italy, however, Federico Martinotti (1860-1924), the director of l'Istituto Sperimentale per l'Enologia di Asti, is considered the inventor, who apparently carried out extensive experiments in his institute even before Charmat. He used closed containers that could withstand a pressure of up to 6 bar. This is why the process is patriotically known in Italy as Metodo martinotti, Metodo martinotti-charmat or Metodo italiano.
But also others, such as the French chemist Edme-Jules Maumené (1818-1898) in collaboration with L. Jaunay, were already working on sparkling wine fermentation in pressure-resistant large containers in 1852, so that there are probably several fathers or inventors for this process. In any case, in 1930, more than five million bottles of sparkling wine were already produced in France in this way and the process became established worldwide. For it was the first time that it allowed the production of inexpensive sparkling wines and turned the exclusive luxury article into an affordable product. After the Second World War, perfection was driven forward, especially in Germany. Today, most sparkling wines and spumanti are produced in this way. With Cava, Champagne, Hauersekt and Winzersekt, however, the process is not permitted in principle.
The temperature-controlled pressure tanks hold 100,000 to 200,000 litres of wine. By adding the dosage (Fülldosage) the secondary fermentation is initiated. The resulting carbon dioxide remains trapped in the pressure tank. The yeast in the tank is periodically stirred up by agitators to enrich the wine with these flavours. After storage, usually for several months, the shipping dosage is added for the desired residual sweetness. Finally, the tank is cooled down to minus degrees, whereby the carbon dioxide becomes "inactive" and remains bound in the sparkling wine. Now a filtration and the bottling follows.
The advantage of the Méthode charmat is that the second fermentation is much cheaper, faster and less complex than the traditional Méthode champenoise or Méthode classique with regard to bottle fermentation and dégorgement (removal of the yeast sediment). However, the quality of a bottle fermentation with high pearlability can usually not be achieved with this method. However, a high-quality base wine can also be matured in steel tanks with a correspondingly long yeast aging to a top product. A slightly modified form is the continuous process developed in Russia. Tanks are also used in the transvasier process.
A detailed description of sparkling wine production with all processing steps can be found under Champagne. A complete list of the numerous vinification measures and cellar techniques, as well as the types of wine, sparkling wine and distillate regulated by wine law, can be found under the keyword vinification. Comprehensive information on wine law can be found under the keyword wine law.
Graphic: Champagne Winery J.Oppmann AG