Effects of Pre-Veraison Irrigation Cutoff and Skin Contact Time on the Composition, Color, and Phenolic Content of Young Cabernet Sauvignon Wines in Spain

Abstract

During the third year of an irrigation trial on Cabernet Sauvignon in Spain, pre-veraison cutoff (PRE) as opposed to post-veraison cutoff (POST) led to a reduction in berry size and a delay in fruit maturity as indicated by percent soluble solids. A microvinification trial was carried out using the fruit from these two irrigation treatments to determine their effects on subsequent wine composition and color development in response to two different skin contact times — five days (5D) and 30 days (30D). Wines made from the PRE treatment fruit had lower ethanol content, lower pH, lower potassium concentration and higher titratable acidity than POST wines. The time of skin contact did not influence any of these parameters in the finished wines. The extraction of anthocyanins during fermentation was greater from PRE fruit. However, the loss of anthocyanins at the end of the fermentation was also greater in PRE wines, thereby canceling out differences in the concentration of anthocyanins attributable to the irrigation treatments. Extended skin contact (30D) resulted in a greater decrease in total anthocyanins after fermentation and a greater extraction of other phenolic compounds in wines made from both irrigation treatments. Skin contact time had a larger influence than irrigation cutoff date on the concentration of total anthocyanins and total phenols in the wines, whereas the irrigation treatment had a larger influence on anthocyanin equilibria.