Sensory and chemical effects of two alternatives of prefermentative cold soak in Malbec wines during winemaking and bottle ageing

摘要

Two alternatives of cold soak (CS), traditional external refrigeration (CS-T) and use of solid CO_2 (CS-DI), were evaluated in Malbec wines and contrasted against a control (C) during winemaking and up to 24 months of bottle ageing. Sugar consumption up to 5 g L day~(-1) was observed in CS-T during the CS period. Both the viability of the population of Saccharomyces and non-Saccharomyces were maintained during CS. CS-T was detrimental for the anthocyanin and phenolic content and caused a reduction of absorbance in the visible spectrum of the wines relative to C and CS-DI. CS-DI had an early positive effect in the anthocyanin content and chromatic properties, but this effect subsided after 6 months of bottle ageing relative to C. From a sensory standpoint, CS-T had the lowest colour saturation and a marked acetaldehyde character. CS-DI wines were the most saturated in colour at press and early ageing, whereas a balsamic-like aroma developed during bottle ageing. C wines were characterised by red fruits aroma, reduction and astringency early during winemaking, but a decrease in astringency and the reduction character occurred during bottle ageing.