Sparkling wines are those containing carbon dioxide of endogenous origin, i.e., which is created on the wine with a second fermentation process. This is caused by the addition of sucrose and special yeasts that convert the sugar into alcohol and carbon dioxide.
There are two possible methods to use in this second fermentation depending on where takes place. On one side is the champenoise or traditional method, in which the second fermentation in the bottle itself; and secondly, the Granvas system or large containers in which the second fermentation is carried out in large steel tanks. The latter is the method used to achieve the anti Italian spumante and most of the German sparkling
Selection of base wine
The best for the production of sparkling is pale, clean to the nose, fruity palate, acid, light, with an alcohol content not exceeding 11 ° C and low in sulfur dioxide. In addition, both a young wine as one that has a certain aging in wood can be used.
Second fermentation in the bottle and rhyme
The second fermentation is induced with the addition of the base wine called tirage, a compound formed by dissolving sugar, selected yeast included in a generally older wine that the wine base and a small amount of a clarifying called bentonite. Liquor circulation and the cuvee are mixed in a tank and then moved to the bottles through a process called circulation or filling bottles. The bottle design plays a fundamental role in this second fermentation because their form has been calculated to withstand the enormous pressure that occurs within it. Once filled and securely closed thanks to a star stopper, the bottles are transferred to the cellars, where the fermentation occurs.
The cellars are ships, usually underground, which are characterized by maintaining low temperature throughout the year as well as an adequate level of humidity. In them, the bottles are placed in a horizontal position forming blocks rhyme.
Yeasts do their work in this position for a minimum period of nine months. However, if the fermentation is lazy required before the five months, the estimated lifespan of yeast, the bottles are transfer yourself from a rhyme to another to shake and remove the scum and so revive the role dormant yeast. Throughout this process it is very important to monitor the state of carbon and that this is linked into the bottle properly. This will ensure that the subsequent detachment of the gas in the glass is thin, long and slow.
The following process is the second fermentation rinsing, it involves bringing the sediment remains in the outlet of the bottle. To do this, the bottles are transferred to the desks, some slightly sloping wooden furniture. There are placed leaving the necks, the upper part of the throat where it attaches to the bottle, in its lower region with the aim that the remains are grouped near the mouth.
For rinsing the removed, an operation which lasts about 21 days and in which an expert makes an abrupt turn daily bottle to produce the sliding of the sediments to the outlet, it is performed while the liquid remains stable, transparent and clean. It is a movement that is done with the wrist and to perform correctly, each removed should correspond to 1/8 of the circumference of the bottle. Traditionally, this procedure has been carried out manually, but increasingly are using special machines.
Disgorging and liquor issue
Subsequently, the bottle neck - where the sediment sludge - is immersed in a bath of brine (salt-laden water) that is at a temperature of 25 Celsius. In this way the grounds are trapped in a small ice block.
Sediment block is expelled through a procedure called disgorging. The bottle is uncovered so that the reservoir is projected outward through a small explosion while the slightest loss of carbon dioxide is avoided. Disgorging can be performed both manually and by specific automatic machines.
The last process prior to breeding Sparkling is the addition of expedition liqueur, usually, is a very stable and completely neutral old wine to which you have added a number of products that confer personality after foamy. Among them are the necessary sugars to bring the wine to the different types of sparkling. Thus, depending on the sugar content in grams per liter, the sparkling are classified as:
- Brut Natural or Brut Nature: From 0-3 grams of residual sugar (no addition of expedition liqueur).
- Extra brut: Sparkling wine with a sugar content of less than 6 grams per liter.
- Brut: 0 to 15 grams per liter.
- Extra Dry: 12 to 20 grams per liter.
- Dry: 17 to 35 grams per liter.
Occasionally, the sparkling is subjected to a process of breeding, resulting sparkling born large reserves, for which the regulation establishes a period which reaches five or six years, considered time for aging rum. With aging, the foam loses bravery but becomes more complex as a result prolonged contact with the yeast.