Charmatmenetelmä

The Charmat method, also known as the tank method or cuve close, is a widely used technique for producing sparkling wines, particularly Prosecco and Asti Spumante. It was developed by French chemist Eugène Charmat in the early 20th century. This method involves a secondary fermentation that takes place in large, sealed stainless steel tanks rather than in individual bottles, as is done in the traditional method.

The process begins with a base wine, which is transferred into a pressurized tank. Yeast and a measured amount of sugar are added to initiate the second fermentation. As the yeast consumes the sugar, it produces carbon dioxide and alcohol. Because the tank is sealed, the carbon dioxide cannot escape and dissolves into the wine, creating the characteristic bubbles. This secondary fermentation typically lasts for a period ranging from a few weeks to several months.

Once the desired level of effervescence is achieved, the wine is chilled to stop the fermentation and then filtered under pressure to remove the yeast sediment. The wine is then bottled directly from the tank, also under pressure, preserving the carbonation. The Charmat method is favored for its efficiency, cost-effectiveness, and ability to preserve the fresh, fruity aromas of the grapes, which are often dominant in wines produced this way. It allows for large-scale production while maintaining the wine's vibrant character.