Type of cork to use
The natural cork stoppers of better quality should be used in VQPRD and AGEING WINE. All the others, especially the colmated and agglomerated ones, should be destined for a more current wine.
The cork stoppers dimensions
These dimensions should take into consideration the following aspects:
The kind of wine - For ageing wine we advise stoppers with 45 and/or 49 mm of length and 24 mm of diameter; also for these wines, and for the sparkling wine too, 25 or 26 mm diameter cork stoppers are recommended.
The bottleneck dimension - The cork stopper should be dimensioned bearing in mind the bottleneck's profile, because the length of the cork is conditioned by the bottle's conicity. In what regards the stopper's diameter, it should be about 6 mm superior to the average diameter of the bottle's bottleneck.
Type of surface treatment
This should be applied taking into consideration the bottler's indications about the wine's characteristics (type of corkage and environmental conditions surrounding it).
Handling and stockage of the cork stoppers
In order to avoid the risk of having the surface treatment altered, the corks, after being treated, shouldn't be exposed to temperatures above 25 and below 10 degrees. Also, the humidity level should only be between 50 and 70 %.
- The bottlenecks must be dry during the corkage; the filling up level of the wine should be 15 to 20 mm below the cork, so that posible liquid thermic dilations do not create very high internal pressures;
- The corker-machine shouldn't press the stopper more than 1,5 mm above the diameter of the bottle's entry bore. On the other hand, compressions above 1/3 of the cork stopper diameter must be avoided;
- It is essential that the proper maintenance of the corker-machine is done, especialy of its jawsm, which must never work excessive speed, in order to avoid pincers, folds or even cuts in the cork stoppers;
- So that the dimensional recovery of the stopper is alowed and, in this way, the creation of an immediate liquid passage is avoided, the bottler should wait at least 10 min. before putting the bottle in an inverted or laid down position.
Transportation and storage of the bottles
The rise of the internal pressure of the bottle caused by temperature fluctuations may lead to the occurrence of leaks or even the cork stopper's exclusion.