Rioja wines are protected by the oldest Designation of Origin in Spain, officially recognised in 1926. In 1991, it was awarded the highest category -Calificada- making Rioja the only designation in Spain to be so honoured. Its Regulations establish the borders of the production area, the grape varieties that may be grown, maximum allowable yields, approved vinification and ageing techniques, and so on. The Control Board, which includes grape growers, winemakers and Administration representatives, is the body charged with ensuring compliance with the D.O.'s Regulations in order to protect the type and quality of Rioja wines.
The Control Board runs a strict and efficient control system from production to commercialisation, both for the quantity and quality of protected wines. For this, all Rioja wines have to undergo analytical and organoleptic tests to determine if the wine is worthy or not of the Denominación de Origen Calificada. The analyses are carried out in the official laboratories of the three Autonomous Communities and the blind tastings are performed by a panel of grape growers and oenologists.
The control continues through the ageing process to commercialisation when the Board awards the bodegas the corresponding numbered back labels or seals which guarantee the origin, vintage and ageing of the wines. The compulsory bottling of Rioja wines in the production area also contributes to ensuring their quality and type.