Soft pressing of the entire grape, the must is stored in a tank at -2°C followed by slow fermentation in an autoclave at a controlled temperature until achieving an alcohol content of 5%. During this process, a part of the carbon dioxide developed during fermentation remains “entrapped”, giving the wine its mild, natural effervescence. Before bottling, it then undergoes a process of micro-filtration to give the wine its clarity, purity and stop any further fermentation of the yeasts.