The winemaking process was carried out in the experimental
cellar located at the University of La Rioja. Identical vinifications
were performed with the grapes from each experimental plot as
follows: grapes were crushed, destemmed and placed in a metallic
fermentation vessel (40 L) that was supplied with SO2 (at
50 mg L1) concentration. The temperature during alcoholic fermentationemaceration, which took 14 days, was 17e21 C. At the
end of the process, the wine was strained off, grape residues were
pressed and the wineemust mixtures were transferred to a
metallic vessel where it was supplied with SO2 (at 30 mg L1). Prior
to bottling, a step of cold clarification was carried out