Bottle fermentation

Bottle fermentation for champagne: a detailed look at the process

Bottle fermentation is a central process in the production of Champagne and other sparkling wines, which is responsible for their characteristic perlage and fine flavour. This traditional process, also known as Methode Champenoise or Méthode Champenoise, is a skilful technique that distinguishes Champagne from other sparkling wines.

Basic principle of bottle fermentation

Bottle fermentation begins after the first fermentation of the champagne, which takes place in large stainless steel tanks or wooden barrels. During the first fermentation, the base wine is produced, which consists of grapes from the Pinot Noir, Pinot Meunier and Chardonnay varieties. Once this base wine has developed the necessary characteristics for the champagne, it is bottled.

Dosage and second fermentation

The second fermentation in the bottle begins after a mixture of sugar and yeast, known as "Liqueur de Tirage", has been added to the base wine. This mixture serves as food for the remaining yeast cells and triggers the second fermentation in the bottle. During this process, sugar is converted into carbon dioxide and alcohol. The carbon dioxide remains in the bottle and dissolves in the wine, creating the fine bubbles that make champagne so distinctive.

Maturation and shaking

After the second fermentation, the Champagne is aged on the lees for a certain period of time to develop additional flavours and complexity. This maturation on the lees, also known as "maturation sur lies", usually lasts at least 15 months for Champagne, although many prestige cuvées mature for longer.

During maturation, the champagne must be "shaken" regularly. During riddling, the bottles are gradually brought into a vertical position and gently swirled to move the yeast into the neck of the bottle. This is done manually or mechanically and is a crucial step in keeping the champagne clear and removing the yeast.

Disgorging

Once the champagne has matured sufficiently and the yeast is fully concentrated in the neck of the bottle, the next step, "disgorging", is carried out. During this process, the yeast plug that has formed in the neck of the bottle is removed. To do this, the neck of the bottle is immersed in a frozen bath, which freezes the yeast and allows it to be easily removed from the bottle.

After disgorging, the champagne is supplemented with a dosage, a mixture of wine and sugar. This determines the degree of sweetness of the champagne and can range from brut (very dry) to doux (very sweet). The bottle is then finally sealed and corked.

Quality and style

Bottle fermentation not only gives the champagne its characteristic effervescence, but also complexity and depth of flavour. The long maturation on the lees results in a fine, creamy texture and a rich flavour profile that often includes notes of toasted bread, yeast, nuts and fresh fruit.

An important feature of bottle fermentation is that it offers the possibility of "vintaging" champagne, i.e. producing champagne from a single vintage. Vintage champagnes are often particularly sought after as they reflect the unique characteristics of a particular vintage and usually offer an even more complex variety of flavours.

Historical significance

Bottle fermentation has a long history and was first practised in the 17th century in the Champagne region of France. It was popularised by the efforts of Champagne houses such as Maison Ruinart and Moët & Chandon, which perfected the technique and made it internationally renowned.

Over time, bottle fermentation has become a symbol of quality and craftsmanship in the sparkling wine sector. Today, it is used by many winemakers around the world to produce sparkling wines of the highest quality, although the traditional approach of Champagne is still considered the benchmark.

Conclusion

Bottle fermentation is a complex and precise process that turns the production of champagne into a work of art. From the start of the second fermentation to the final dosage, every step is crucial for the end product. This traditional process ensures the fine bubbles, the complex flavours and the unmistakable elegance of champagne. The effort and dedication that goes into bottle fermentation is a key reason why champagne is appreciated and celebrated around the world.