Fermentation

Fermentation, often also referred to as fermentation...

...is a fundamental term in winemaking and refers to a complex biochemical process that is deeply embedded in the art and science of wine and champagne making. This process plays a central role in the conversion of sugar into alcohol and significantly influences the characteristics of the final product.

Basic principles of fermentation

Fermentation is a natural process that has been used by humans for thousands of years to produce alcoholic beverages. Essentially, fermentation describes the conversion of sugar into alcohol and carbon dioxide by microorganisms, especially yeasts. This process begins when yeast is activated in a liquid containing sugar, such as grape juice or must. The yeast metabolises the sugars and produces alcohol and carbon dioxide as by-products.

During fermentation, the sugars are converted into two main products: Ethanol, the main alcohol in wines, and carbon dioxide, which is responsible for effervescence. The specific types of yeasts and the environmental conditions, such as temperature and pH, significantly influence the speed and outcome of this process.

Fermentation in wine production

In traditional winemaking, the fermentation process begins as soon as the must, the freshly pressed grape juice, comes into contact with yeast. This yeast can be either naturally occurring or artificially added. The choice of yeast type is crucial as different yeast strains can produce different aroma profiles and flavours. The process typically takes place in fermentation vessels made of either stainless steel, wood or other materials.

During the first stage of fermentation, known as primary fermentation, most of the sugar is converted into alcohol and carbon dioxide. This process can take several days to weeks and is carefully monitored to ensure that the correct conditions are maintained. Important factors include temperature, as temperatures that are too high or too low can affect yeast activity, and aeration, which is necessary for healthy yeast activity.

Secondary fermentation for champagne

In contrast to the production of ordinary wine, the wine goes through a Champagne an additional phase known as secondary fermentation. This special fermentation process takes place directly in the bottle and is crucial for creating the characteristic effervescence of the champagne.

Secondary fermentation begins after the base wine used to make the champagne is bottled and a mixture of sugar and yeast is added. This mixture is known as "liqueur de tirage" and ensures that a second fermentation starts in the bottle. During this second fermentation, sugar is once again converted into alcohol and carbon dioxide by the yeast, whereby the carbon dioxide cannot escape and dissolves in the bottle. This leads to the formation of the fine bubbles that make champagne so unique.

This process of secondary fermentation takes several weeks to months and takes place under controlled conditions. The bottles are regularly shaken and tilted in a process known as "remuage" to move the yeast deposits into the neck of the bottle. After secondary fermentation is complete, the yeast is removed through a process called "dégorgement". The result is a sparkling, refreshing champagne with a fine perlage.

Influence of fermentation on flavour

Fermentation not only influences the alcohol content and effervescence, but also the flavour characteristics of the wine or champagne. During fermentation, various aromatic substances and flavour compounds are formed that determine the complexity and depth of the end product. In wine production, the flavours formed during fermentation can be fruity, floral or spicy, depending on the grape varieties and yeasts used.

In Champagne, secondary fermentation significantly influences the texture and flavour of the drink. The duration of ageing on the lees, known as "mise en cave", contributes to the development of complex flavours and a creamy texture. The process of ageing on the lees gives the champagne notes of brioche, nuts and honey, which are appreciated for the highest qualities.

Conclusion

Fermentation is a crucial and complex process that forms the basis for the production of wine and champagne. From the primary process of converting sugar into alcohol and carbon dioxide to the secondary fermentation in Champagne production that creates effervescence, fermentation has a significant impact on the final product. A deep understanding of this process is essential for the production of high-quality wines and champagnes that reflect the art and science of fermentation.