The Effect of Juice Turbidity on Aroma Development in Aging Sauvignon Blanc (2017)

This study examines the impact of different turbidity levels in Sauvignon blanc juice on aroma development. Sauvignon blanc for this study was all harvested on the same day from the same block at Veritas. The grapes were destemmed and cold soaked at 45°F for 19 hours with 35ppm liquid sulfur dioxide and pressed the following day. Only free run juice was used. After the juice was pressed off Cinn-Free was added at a rate of 1.6ml/hL. The juice was settled for two days and then racked off of juice lees and inoculated with X-5 Yeast. At this point lees were added to two of the barrels to two levels of NTU (65.8 NTU and 195 NTU), while the third barrel kept the naturally occurring NTUs of processing (19 NTU). After fermentation the wine was allowed to settle and then was racked off of fermentation lees before barreling into three identical neutral barrels. At racking the medium and high rates of turbidity were combined, for two total treatments: 1) a low turbidity treatment and 2) a high turbidity treatment. No major differences in wine chemistry resulted from the turbidity differences. Thiol parameters may have slightly increased in the higher turbidity treatment. Overall, winemakers were able to distinguish statistically significant differences between wines (p<0.001). This may have been due to slight turbidity differences present in the glasses. No strong trends could be seen with the descriptors used in this study.

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The Effect of Juice Turbidity on Aroma Development of Sauvignon Blanc (2016)

This study compares the effects of fermenting Sauvignon Blanc juice at a low (50 NTU) or high turbidity (250 NTU). Juice from the same pick of Sauvignon Blanc was settled and racked into stainless steel barrels. Turbidity was adjusted by adding back fine lees to the juice. All other treatments between wines were the same. No major chemical differences could be found between juice or wine, except that the juice with higher turbidity had slightly higher YAN and its wine had slightly lower alcohol. High turbidity greatly increased 3-mercaptohexanol and 4-methyl-4-mercaptopentan-2-one, but decreased 3-mercaptohexylacetate. Triangle testing suggests that the wines were significantly different (p<0.001). No major preference could be seen for one wine over the other. No major trends could be found for the descriptors used in this study, despite the wines being found to be significantly different. There was a slight tendency for the High NTU wine to have more Varietal Character and Overall Aromatic Intensity, while having less Body.

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Press Enzyme Comparison: Cinn-Free vs. Lafazym Press (2015)

The effect of press enzymes Cinn-Free (ScottLabs) and Lafazym Press (Laffort) on finished Sauvignon Blanc wine were compared.  There were no chemical differences between the wines except that the Lafazyme-treated juice had a slightly higher titratable acidity.  There were no significant sensory differences between the wines, but there seemed to be a slight preference for Lafazyme.  No yield comparisons were made.

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