The Bairrada DO is included within the region which currently bears the designation Beira Atlântico, and the areas under the DO Bairrada formed part of the more extensive viticultural region already mentioned which was known as IG Beiras.
Wine production in the region dates back to Roman times, as evidenced by the wide variety of wine presses hewn out of the granite rock (anthropomorphic wine presses) where wine was produced during this period. Documented evidence of wine production dating to the 10th and 11th century has been discovered. The tradition of these wines dates back to the reign of D. Afonso Henrique, who authorised the planting of vineyards in the region on condition that he received one quarter of the wine they produced. As early as during the reigns of D. João I and D. João III, measures were taken to protect the wines from this area of the country, given their excellent quality and social and economic importance. Extending from the Minho to the Alta Estremadura, it is a region of predominantly intensive agriculture, with a variety of crops grown on small parcels of land, where the vine occupies pride of place and the quality of its wines justifies the recognition that DOC “Bairrada” bestows upon them. The officially approved certification authority for vitivinicultural products entitled to bear the designations of DO Bairrada and IG Beira Atlântico is the Comissão Vitivinícola da Bairrada (Bairrada Vitivinicultural Commission), abbreviated to CVB.
The soils come from various geological eras, but are predominantly poor. They are primarily divided between calcareous clay terrain and long sandy bands, constituting a wide variety of soil types, depending on which element is predominant. Vines are cultivated mainly in clay or calcareous clay soils. The winters are long and cool, the summers hot, tempered by the winds from the east and north-east dominant in those regions closer to the sea. The climate is a Mediterranean-Atlantic one, with an annual rainfall of between 900 mm and 1,100 mm. For the most part, the region is flat, with vineyards seldom situated at altitudes higher than 120 metres. Given its flatness and proximity to the ocean, it enjoys a temperate climate with an extremely strong Atlantic influence, with frequent rains and mild average temperatures. Forming of a strip along the coast with a high population density, rural property is divided into thousands of small parcels, with the average area of vine cultivation rarely exceeding one hectare of vines, thus favouring the presence of large cooperative cellars and large winemaking companies as well as a number of producer-bottlers who are a credit to the region.
The viticultural land of the Beiras region used to cover an extensive area, and used to produce around 13% of the volume of all wines produced in Portugal.
The official borders of the Bairrada were established in 1867 by António Augusto de Aguiar, and it was one of the first regions in Portugal to adopt and develop sparkling wines, given that the region’s cool, humid climate with its strong maritime influence favours its production, yielding grapes with a low alcohol but high acid content, both essential factors in the making of sparkling wine.