In Navarra, two types of sweet wines are produced: the naturally sweet, in which sweetness and alcohol in the wine come exclusively from sugars of the grape, and fortified wines, in which alcohol is added to partially fermented or non-fermented must. Let’s see how they are made.
Naturally sweet wines. We use overripe grapes (usually of the variety Moscatel de Grano Menudo) to produce this wine, which has a high sugar content. Because the fermenting must have a good balance between the acquired alcohol (which comes from the fermentation) and residual sugars, we end the process without allowing all the sugar to be transformed into alcohol. To achieve this, the wine is racked, cooled, and filtered, and sulfites are added. Before sterile bottling, antimicrobial filtration should be performed to strictly eliminate all possible microorganisms, so that the wine does not begin to ferment again in the bottle.
Fortified Wines. We start with a grape (Moscatel de Grano Menudo, of course) which is perfectly mature and very low yield – 1.25 tons per acre – from which we get a sweet must, dense and syrupy, that is not allowed to finish fermenting. Like other great fortified wines (Port, Madeira, Pedro Ximenez, etc.), when there are still unprocessed sugars in the wine, alcohol is added to extinguish the yeast. We thus obtain a fortified wine with an alcohol percentage close to 15%, which is then aged through a special process. The wine is poured into damajuanas, the traditional glass jugs, which are then placed on the hills of the winery and exposed to the elements: the light and sun cause oxidative aging of great personality. This aging is complemented by three or four years of barrel aging in wooden casks before bottling.