The Consejo Regulador (regulatory authority) for the vineyards and wines of Rioja was established in 1926. They carefully maintain and publish statistics of the Rioja Wine Industry, which allows a number of important parameters to be tracked through time.
In the 2013 vintage, the wineries within the Rioja DOCa produced 2.64 million hl of wine. As part of the Rioja wine approval process, there is a regulatory requirement for a sample from each tank of wine to be subjected to analytical (and sensory) investigation. Last year 3,973 wine samples were analysed by the Rioja Control Board, for parameters such as pH, volatile acidity and Alcohol content (abv). Although the raw data has not been published, the summary data provides a useful snapshot of the vintage, and provides the opportunity to compare with earlier vintages as far back as 2001.
In the case of alcohol content for red wine there is, as would be expected with any agricultural product, a good deal of variation between vintages. Underlying this scatter is an upward trend which amounts to an increase of abv of ca. 0.5% from 2001-2013. (The p-value associated with the trend line is 0.03; values of less that 0.05 are generally considered significant). The causes of this increase (e.g. climate? picking dates?) are presently unclear, and there is currently no reason to believe that it will necessarily continue in future.
Rioja has a long history of winemaking and in 1925 became the first wine region in Spain to obtain Denominación de Origen (DO) status. At both home and abroad, Rioja is most well known for the production of red wines.
Over the last quarter century, the total productive vineyard area of the Rioja D.O. has increased from ca. 40,000 ha to just over 60,000 ha. During this period black varietals have increased their area whilst white varietals have shown a small decrease. As a result, white varietals have moved from occupying 23% of the total productive vineyard area in 1985 to occpying only 6% of the total vineyard in 2012.
Over the last five years the areas of total black and total white varietals have remained more or less unchanged. Yet this should not be mistaken for a period of stasis in the vineyard. Following years of consultation, the Consejo Regulador for D.O Rioja allowed the introduction of nine new varieties in 2007. This led to a minor revolution in the vineyard, the results of which are only just beginning to be experienced.
White Rioja is produced predominantly from the varietal Viura (which is known outside of Rioja as Macabeo). In 2008 Viura accounted for 96% of the white varietals vineyard, but in the wake of the new regulations growers have taken the opportunity to replace Viura with other varietals. The apparent reason for this is that Viura, with its tendancy towards low aromatics and neutral characteristics, often yields wines which are of simple nature and soon forgotten. Only careful vine management, which usually means lower than average yields on sites away from the valley floors, can produce quality fruit. A small number of producers such as Allende and Marqués de Murrieta couple carefully selected fruit with barrel fermentation and battonage which yield complex wines capable of ageing, but these are perhaps of minority interest.
The traditionally permitted blending partners for Viura have been Malvasia and Garnacha Blanca. Together these account for less than 100 ha of vineyards, so supply is very limited. The Consejo Regulador revisions of 2007 permitted the use of three native white varietals, namely Tempranillo Blanco, Maturana Blanca and Turruntes. More controversial was the decision to allow plantings of Chardonnay, Sauvignon Blanc and Verdejo, which are neither native nor traditional varietals. To date growers have tended to opt for the non-native varietals, with Tempranillo Blanco being the only new native varietal to be taken up to any significant extent. Verdejo is now the most planted secondary white grape varietal in Rioja.