
In Navarra, dry white wines are made principally from the Viura and Chardonnay varieties.
After their journey to the winery, the grapes are taken to the crusher – destemmer in order to totally or partially remove the stalk and lightly crush the berries. Before pressing, some wine-makers macerate the must (grape juice) with the skins at 14ºC for a few hours for greater aroma extraction. The grapes are then put into the press and the pressure is progressively increased; this makes it possible to separate the first pressings (free run juice) from the final pressings in which the increased pressure gives rise to a rougher grape must, of a lower quality.
Once the grape must has been obtained, it is sulfated to prevent the oxidization of the must and the development of undesirable micro-organisms. The grape must is then racked to remove any impurities. This racking process can be either static, where the grape must is left in the tank for 24 hours to allow the sediment to settle on the bottom, or, in large scale wineries, kinetic, occurring by centrifugation.
A clear must is thereby obtained which is then fermented either by the action of native yeasts or by using a good strain of active dry yeasts. The fermentation can take place either:
• In the tank: Today, the large majority of tanks are made of stainless steel and incorporate a cooling system for low temperature fermentation (17 to 20 ºC) in order to protect the aromatic finesse. Once the fermentation has been completed (between 7 to 20 days), the wine is decanted into another vat where it is sulfated yet again.
• In an oak barrel: The best white wines are fermented in this type of container. The barrels, the majority of which are new, are filled with the must. Given their small volume (generally 225 liters), the heat release is limited and the fermentation is slow.
In addition to the oak aromas and tannins imparted by the wood, after fermentation the wine is also enriched by maturing in contact with the yeast lees, which are regularly stirred into the wine through the “bâtonnage” technique. This gives a more unctuous, mouth-filling wine. The duration of the ageing process is adjusted to ensure that the wood flavour does not take over the wine; between the months of March to June the wine is transferred from the barrel to a vat. Malolactic fermentation is rarely used given the fact that the white wines support a fresh acidity very well. However, if the wine is too acidic, then partial or complete malolactic fermentation may be performed. Once the fermentation, and possible ageing, has been completed, the wine is fined and stabilized prior to bottling.
Adapted from http://www.navarrawine.com.