The impact of postharvest cooling of Sauvignon blanc grapes on the sensory profile and the chemical composition of the wines

Abstract

Rapid processing of grapes after harvest has always been considered essential for achieving a balanced sensory wine profile. However, the immediate postharvest period represents a particularly labor intensive phase for wineries, often requiring weekend work and overtime hours. Sauvignon Blanc is among the 20 most widely cultivated grape varieties globally and is grown on approximately 500 hectares in South Tyrol, Italy. During the harvest season, the region’s fragmented wine industry faces challenges due to limited human resources.

To mitigate the workload during the postharvest period, our study investigated various shortterm storage conditions and their impact on the sensory and chemical profile of Sauvignon Blanc wines. The focus was placed on sensory aspects, but quality parameters and volatile aroma compounds were also analyzed. Additionally, the effect of cold maceration following the grape storage process was examined.

Cooling grapes in harvest bins at 8 °C for 48 hours had only a minor impact on the sensory profile of the wine, whereas storage at 20 °C resulted in significant negative changes. An additional cold maceration of the must at 8 °C for 16 hours had a more pronounced sensory effect than cooling the entire grapes. Our results show that cooling grapes postharvest is a feasible solution to reduce the workload during the harvest period without significantly compromising wine quality, provided temperature conditions are controlled. A subsequent cold maceration period should be evaluated on a case-by-case basis for its relevance.