A winery-scale trial of the use of antimicrobial plant phenolic extracts as preservatives during wine ageing in barrels

Abstract

Antimicrobial plant extracts rich in polyphenols have recently been proposed as a total or partial alternative to sulfites during winemaking. This paper reports a first winery-scale trial of the addition of antimicrobial plant extracts during wine ageing in wood. Before being distributed in oak barrels, a Verdejo wine was treated with either a SO2 regular dose (160mg/L) or with a SO2 half-dose (80mg/L), together with two phenolic-rich extracts from eucalyptus leaves and almond skins (100mg/L). Some of the wine was also stored in a stainless steel tank for comparison. After 6 months of ageing, the wine treated with the phenolic extracts remained microbiologically stable and showed correct enological parameters. Also, the volatile and phenolic composition of the wine was specifically determined to ascertain whether the addition of these phenolic extracts would affect the organoleptic properties of the wine.