Impact of winemaking practices on the concentration and composition of tannins in red wine

Abstract

This review summarises key findings from research on the impact of winemaking practices on the concentration and composition of tannins in red wines. The impact from the point of crushing onwards is summarised from our research and recent literature taking into account the effect of maceration, yeast selection, addition of mannoproteins, addition of oenotannins, fining by animal and plant proteins, filtration, oxygen exposure, barrel treatment, bottling and accelerated-ageing techniques. A sufficient body of evidence has developed in certain areas to make generalisations, but in several other areas tannins continue to show large variability of response to winemaking interventions depending on the grapes and their particular methods of treatment. Progress has been made in determining the underpinning mechanisms for some of the effects, but significant further research is required to understand why many of the effects occur. Knowledge gaps remaining in the area and proposals for future research are identified that will provide the opportunity for improved management of vineyards and winemaking to optimise tannins in grapes and wine, and for increased capacity to meet wine specification, consumer expectations and profitability.