Groundbreaking study connects Garnacha wine age to wine quality

by Deborah Parker Wong

At the Old Vine Conference’s 2025 Meeting of the Minds, held from October 31 to November 4 in vineyards and other venues across Northern California, two of the most pressing questions about old vines were answered: Do wines made from old vines taste better? And is there a scientific method for establishing the age of grapevines?

Joined on stage by Dr. Laura Catena, José Ignacio Garcia López, director and technical secretary of Spanish regulatory body CRDO Campo de Borja, was on hand to present the results of the Garnachas Históricas project, a four-year study conducted by the Universidad de Navarra and Universidad de Zaragoza with leading wineries Ainzón, Aragonesas, and Borsao with the aim of ensuring the survival of historic Garnacha vines, which are indigenous to the province of Aragón.

The taste of old vine wines

The groundbreaking research that connects vine age to improved wine quality was conducted by Dr. Vicente Ferreira, head of the laboratory for flavor analysis and enology at the latter university, and his team who examined wines made from historic vineyards aged between 30 and 90 years. Using a process that combined advanced chemical analysis of aroma-precursor systems and comprehensive quantification of volatile compounds to reveal the full expression of the varietal aromas contained in the grapes, researchers discovered these wines had a more powerful phenolic structure, greater aromatic complexity, and more intensity with respect to expressing the characteristics of the vineyards they were sourced from.

As a result, Dr. Ferreira’s work demonstrates that old vine grapes have a higher potential for storing aromas that are subsequently released, providing a more intense and complex terroir expression and possess a far greater capacity to age.

Spain’s Campo de Borja D.O. lies in the northwestern quadrant of the Zaragoza province, which is a transitional zone between the plains of the Ebro River and the Moncayo Massif of the Sistema Ibérico. The oldest vineyards of the D.O. date back to 1145 and more than 2,000 of the 5,000 hectares of Garnacha are between 30 and 50 years old. The historic Garnacha vineyards here are shown to contain more guaiacol and eugenol, which contribute to black fruit notes.

Grapes from the region’s eastern and southeastern municipalities of Pozuelo,
Magallón, and Tabuenca were found to contain more varietal thiols, vanillin,
and beta-damascenone (found in raspberries), which contribute freshness and
fruity aromas in wine. Grapes from the western subregions of Borja and Ainzón as well as Fuendejalón in the southeast have marked floral aromas from higher concentrations of terpenes and beta-ionone.

According to Ferreira, these results validate the concept of old vine terroir expression in wine and our understanding thereof.

The Garnachas Históricas projecthas also produced a scientific method for certifying the age of a vineyard. Dr. Gonzaga Santesteban, professor at the department of agronomy, biotechnology, and food at the Universidad de Navarra, and his team have discovered they can do this using a combination of data, including aerial photographs, vine measurements, and genetic samples from old vine rootstocks.

Given that grapevines are lianas—or ligneous climbing plants—and that their internal structure disintegrates over time, their age cannot be determined by counting growth rings, as we do for trees. Instead, researchers closely inspect pruning cuts to calculate the annual growth rate of an individual vine that they can then compare to others within a vineyard.

Historical information about the availability and prevalence of various rootstocks is also cross-referenced with genetic identification to further validate the age of a vineyard. Proving that these historic vineyards produce more complex wines serves to increase their market value, which helps
ensure their survival.