Spanish system for quality wines produced in a specified region (QWPSR). Each DO has a set of rules defining the region of production, permitted grape varieties and yields, and sometimes alcohol and sugar levels.
For some DOs, a tasting panel must approve wines before they are sold. The system provides a guarantee of authenticity for the consumer while protecting the producer from competition. A higher level DOCa also exists and Rioja was the first DO to be promoted. See also ‘vino de la tierra’, ‘vino de mesa’.