This study examines the impact of directly processing fruit after harvest compared with harvesting fruit after it has been refrigerated overnight. Cabernet Sauvignon grapes were picked from the same block on the same day and were either destemmed into T bins on the same day of harvest or refrigerated overnight before processing the next day. All other treatments were identical. The grapes which were refrigerated overnight exhibited slight increases in color intensity, but otherwise no major chemical differences could be found between treatments. Overall, the wines were not found to be very different. Very few differences could be seen with descriptive analysis. These results suggest that refrigerating overnight prior to processing may not have any detrimental effects on finished wine quality. However, this study should be repeated multiple times, with several different kinds of grapes as well as different levels of grape quality and cleanliness.
Cabernet Franc grapes were processed traditionally as well as in a grape drying tunnel in order to desiccate them. The Cabernet Franc that went through the drying tunnel had a lower alcohol percent, in spite of the desiccation. The desiccated wine had higher levels of anthocyanins and had higher color intensity. Although there was no sensory difference between the wines, in general people tended to prefer the desiccated wine.
Machine and hand-harvested Viognier were compared for chemical and sensory differences. The machine-harvested wine had higher pH, higher volatile acidity, and lower titratable acidity. There was a significant sensory difference between wines, with most people preferring the machine-harvested wine. This may have been due to some oxidation that the hand-harvested wine experienced.
Machine and hand-harvested Cabernet Sauvignon were compared for chemical, phenolic, and sensory differences. The machine harvested wine had higher titratable acidity and lower pH, but had less anthocyanin. However, color intensity and hue were similar between treatments. The sensory attributes of the wines were significantly different, with most people preferring the hand-harvested wine. This is likely due to a Brettanomyces infection in the machine-harvested wine.
The impact of using harvest bins vs picking lugs on harvest efficiency were compared. Picking lugs result in a time delay due to frequent loading and unloading. In this study this resulted in a 20% reduction in the amount of grapes harvested.