area is home to several dozen varieties of indigenous grapes, with the majority of wine production being made from the Touriga Nacional, Tinta Roriz, Jaen, Alfrocheiro Preto and Encruzado. 80% of the region's production is in red wines, with DOC regulations stipulating that at least 20% of the production must be from Touriga Nacional. Some of the top reserve wine may carry the designation Dão nobre (meaning noble Dão). Another reserve designation, Garrafeira, requires wines to be 0.5% higher in alcohol content than the 12.5% minimum and to spend at least two years in aging in oak. The maximum yield for red wine grapes is 70 hl/ha. The red wines tend to be very tannic due to prolonged periods of maceration during winemaking. Many producers make liberal use of French and Portuguese oak. The style has been improving, with some producers concentrating on making more fruit-forward styles with smoother tannins. Historically, the white wines were known for being over-oxidized and full-bodied, but more modern winemaking has been producing white wines that are fresh, fruity and fragrant. The Encruzado is the principal grape of the area's whites, with some blends of Malvasia Fina and Bical. Garrafeira white wines require at least 0.5% more alcohol by volume than the 11.5% DOC minimum and at least 6 months aging in oak. The maximum allowable yields for white wine grapes is 80 hl/ha. Subregions There are seven subregions within Dão which may be indicated on labels together with Dão: Alva Besteiros Castendo Serra da Estrela Silgueiros Terras de Azurara Terras de Senhorim See also List of Portuguese wine regions References External links Spotlight on Portugal's Dão region Wine regions of Portugal Portuguese products with protected designation of origin