The traditional method, also known as "champenoise", comprises the necessary set of steps for obtaining cava.
This process of production begins with tirage, which is the set of operations culminating in the bottling of the wine, after having added the tirage liquor - a mix of sugar, wine and yeast - intended to cause the second fermentation in the bottle and the resulting formation of mousse.
Next, the bottles must be placed in cool underground stores at a constant temperature, in a horizontal position known as ‘in rows’, and during this phase the second fermentation and subsequent aging occur.
During the second fermentation the yeast acts on the sugar, transforming it into tiny bubbles of carbon dioxide. This phenomenon is a result of the slow process and the fact that this occurs at temperatures below 15ºC.
The legal minimum requirement for this stage of fermentation and aging is nine months, although the majority of cavas remain in the underground cellar far in excess of this.
When the process of aging has finished, the lees (the sediment resulting from the second fermentation) have settled on the lower side of the bottle and must be removed. To do this, the bottles are placed on inclined surfaces known as pupitres and the remuage process begins. This operation consists of giving the bottles an eighth of a full turn every day and gradually increasing the angle of inclination.
This process usually takes around thirty days, after which the bottles end up in an almost vertical position with the sediment having moved towards the cork.
Once the remuage is finished, the bottles are removed from the pupitre and placed in an inverted position, known as “sur pointe” (upside down), until the sediment is removed, an operation known as disgorging.
Traditionally this was done warm, something that required a great deal of skill on the part of the worker carrying out the operation, known as a disgorger. These days, the “sur point” bottles are placed in a machine which freezes the necks and the frozen sediment is easily expelled.
In order to obtain the different varieties of Cava, dosage, a mixture of wine and sugar, may be added in greater or lesser amounts.
Part of the contents are lost during the disgorging operation and the bottle will usually need to be refilled with the same amount of product.
Next, the bottles must be sealed with the final cork which is held in place either with a little wire basket called a muselet, or with a staple. Finally the foil capsule is added and the bottles are labelled and packed.