The harvest takes place between the months of August and October. Following the harvest, the varieties cultivated in our own vineyards for the production of cava Gran Reserva, are then pressed during which time to allow it to slowly ferment. From this fermentation alone, a great quality basic wine is obtained which is balanced in alcohol and acidity and ideal for the production of cava Gran Reserva.

The must (grape juice) is obtained from the gentle pressing of the grapes, and which after following careful fermentation procedures at a controlled temperature, in stainless steel vats, will become wines of a high standard, with a moderate degree of alcohol and high acidity with extraordinary organoleptic qualities for cava Gran Reserva.

The chardonnay for Duran 5V Gran Reserva, ferments in Allier oak French barrel.

During the first few months of the year, and in order to make full use of the aromatic qualities of the wine, our oenologists select a blend from the different varieties to form the base wine of our future cava Gran Reserva.

The bottles are then filled, adding to the coupage, the quantity of sugar and yeast necessary to produce a second fermentation, this time inside the bottle with their corresponding layer of yeasty foam.

The bottles are then placed horizontally inside the wine cellar.

Constant temperature of around 16ºC, the darkness and the silence of the cellar create a perfect atmosphere for the transformation of the base wine into a cava. During the process the yeasts act on the sugar and convert it into tiny carbon dioxide bubbles.

Once the fermentation process has ended the aging process begins: the cava ages with the yeast, the sediments which result from this fermentation process and which lend new aromas and new tastes to the cava.

The duration of the ageing is the most important difference between the types of cava:

After the aging process has been completed, the bottles are placed on the traditional racks used to clarify wine.

The bottles are stirred daily, one by one, to get the lees move towards the neck of the bottle so as to ensure that the wine is left free of impurities.

This process consists of freezing the neck of the bottle and opening it in a vertical position so that the pressure of the carbon dioxide expels the frozen lees, leaving a brilliant, transparent cava.

A small amount of cava is lost in the disgorging process, this is compensated with an addition of wine and sugar, the liqueur d'expédition, which is variable in quantities with respect to the type of cava required. Duran Gran Reserva Brut Nature is totally free from liqueur d'expédition, as the bottles are re-filled with the selfsame cava Gran Reserva.

After the disgorging, the bottles pass a quality control and then are washed and labeled.

All the bottles of Duran Gran Reserva cava are subjected to special and strict quality controls including, organoleptic and analytical examinations by The Regulation Council of the Cava.

This distinction is shown by a small black seal, and it is the best guarantee of Cava Gran Reserva, a high quality cava.