Use of minority grape varieties to mitigate climate change and achievement of balanced wines in Castilla y León (Spain)

Abstract

Castilla y León is the third longest region in the European Union, having more than 85.000 vineyard hectares. One of the most common problems facing wines due to climate change is the imbalance, as they show undue alcohol level and low organic acid concentration. This issue can be mitigated by choosing lesser-used of minority varieties. These varieties have almost become extinct, as some decades ago they did not meet winegrowers’ quality standards, either because they were not productive or because they were unable to fully ripen in the climate conditions of decades ago.

This paper studies the agronomic, oenological and organoleptic behaviour of four red grape minority varieties and the wines elaborated with them in the Spanish region of Castilla y León: Mandón (Arribes del Duero, Salamanca), Tinto Jeromo (Arribes del Duero, Salamanca), Cenicienta (Rueda, Valladolid) y Puesto Mayor (Rueda, Valladolid) in 2024. This study was implemented in a vineyard located in Valladolid (698 MASL), managed in an organic way, common to the four studied varieties, to verify whether their potential, already demonstrated in their areas of origin, accomplish as well when cultivated under different soil and climate conditions. For this purpose, the following agronomic parameters have been selected: number of grape clusters per vine, cluster weight, berry weight and production per hectare. The parameters analysed to determine the grape quality are as follows: soluble solids concentration, pH, organic acids and total polyphenol index. Likewise, we present the main organoleptic characteristics of single-varietal wines produced using a common protocol in 2024 and evaluated by a panel of expert tasters.

The results achieved demonstrate good agronomic performance, with varying production levels depending on the variety studied. The grape quality shows very balanced values, demonstrating a high level of sugar concentration and, therefore, a probable moderate alcohol content (<13.5%), medium-low pH, medium-high acidity and a total polyphenol index that varies depending on the variety. The common organoleptic characteristics of the wines made from these four varieties show a very good alcohol-acid balance, with freshness sensations with fruity notes and varying palate structure depending on the variety studied.

The results suggest that these varieties may be very interesting in the current climate context. The recovery of minority varieties can be a key factor in preventing unbalanced wine composition and to increase the natural resilience of plants to climate change.

This project (0039_MINORSENS_2_E) is co-financed by the European Union through the Interreg VI-A Spain-Portugal (POCTEP) 2021-2027 program.

References

Guía de Variedades Minoritarias I. Ministerio de Agricultura, Alimentación y Medio Ambiente. ISBN: 978-84-491-1450-2. Madrid, 2016.