Late pruning impacts on chemical and sensory attributes of Shiraz wine

Abstract

Background and Aims Warming has two major effects on the wine industry: compressing harvest duration, thus stressing the current capacity of wineries to process more fruit in a shorter time, and compromising fruit composition and wine style. Late pruning can effectively delay vine development and contribute to decompressing harvest, but its impact on wine is unknown. Our aim was to measure the effects of late pruning on wine chemical and sensory attributes. Methods and Results We compared wines made from Shiraz vines pruned in winter (Control), and in two late pruning stages, when Controls reached budburst and 2–3 leaves in two vintages. Late pruning consistently increased wine anthocyanin, tannin, pigmented tannin and colour density and altered the wine's sensory profiles over two vintages. In 2014, colour intensity, fruit aroma, fruit flavours and body were more intense in wine made from late pruning treatments. In 2015, wine made from late pruning treatments showed more intense savoury flavours with a dryer palate and a smoother texture tannin (roughing sub-quality). The colour improvement was associated with cooler temperature 1 week after veraison in the late-pruned vines. Conclusions Late pruning consistently improved wine chemical composition and altered sensory profiles of Shiraz under Barossa Valley conditions. Significance of the Study Late pruning is a cost-effective tool to decompress harvest, with neutral effects on yield and positive effects on wine chemical attributes with enhancement of fruit and colour intensity perception in an extended vintage (2014), and smoother tannin texture with dryer perception in a short and compressed vintage (2015).