Relationships between berry size, berry phenolic composition and wine quality scores for Cabernet Sauvignon (Vitis vinifera L.) from different pruning treatments and different vintages

Abstract

Background and Aims: Commercial winemakers observed differences in wine sensory properties among wines produced from vines of three different pruning treatments in a single vineyard. To clarify the relationships between berries and wine quality, this study examined berry size and berry composition and the quality rating for wines produced from the pruning treatments. Methods and Results: The study was conducted over three seasons. Berries from Machine-, Cane- and Spur-pruned vines were sampled at commercial harvest for analysis of berry size and berry phenolic composition. Wines made from each treatment were assessed for quality by a panel of winemakers. Machine berries were lighter and had higher concentrations of anthocyanins, tannins and total phenolics than Cane or Spur. Machine wines had the lowest quality scores. Comparing vintages, berries from 2004 were lighter, but did not always differ in phenolic composition to other vintages, and wines from 2004 had lower quality scores than the other vintages. Vintage effects were generally stronger than pruning effects. Conclusions: In this study, high berry anthocyanins, total phenolics and tannin concentration measures were not good indicators of wine quality scores. Changes in vineyard treatments and, in particular, vintage influences, produce incremental, but potentially important, changes to berry size and composition and to wine quality. Significance of the Study: This study is unique in its focus on the commercial reality of producing wines to a specific style and quality, while bringing scientific rigour to investigating the relationships between berries and wine quality in this vineyard over a number of vintages. © 2008 The Australian Wine Research Institute Ltd.