Leaf Pulling on One vs Two Sides of Petit Verdot Vines (2017)

This study examines the impact of leaf pulling on one vs both sides of the vine in Petit Verdot. Petit Verdot vines (clone 400, planted 2012, 9x4 spacing, ESVC/CW index of 2.4) from the same block were split so that all vines received leaf pulling on the east side at flowering, and one portion of the vineyard received leaf pulling on the west side as well at veraison. Grapes were harvested on the same date, and all winemaking practices were identical between treatments. Must was inoculated with D80, Enzyme CX was added, punched down twice per day until fermentation was complete, and then switched to one punchdown per day during extended maceration (25 days maceration time, total). Juice chemistry was similar between treatments, although leaf pulling on one side resulted in higher alcohol content and lower acidity. Color and anthocyanin were not much impacted by treatments. Seed tannin indices (catechin, epicatechin, and gallic acid) may have been slightly lowered with leaf pulling on both sides. Tannin may have slightly decreased by this treatment, as well. The sensory results suggest that the two wines were significantly different. No strong trends could be seen for the descriptors used in this study,  although Acidity seemed to be lower in the one sided leaf pulling wine. No major preference trends could be seen between treatments. This study should continue to be performed over multiple years, in different regions, as well as on different grape varieties.

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The Effect of Directly Processing Fruit after Harvest vs Processing after Refrigerating in Cabernet Sauvignon (2016)

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.

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Fermentation Tannins in Chardonnay (2015)

Chardonnay fermented with either Tan Citrus (Enartis) or FT Blanc (ScottLabs) were compared for chemical and sensory characteristics.  No significant differences were found for both chemical and sensory attributes, and there was no real preference between wines.  However, Tan Citrus should be put into a wine fermenting with a B-glycosidic yeast strain for full effect, and the yeast strain used in this study was not identified.

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The Effect of Different Products on Merlot Color Stability (2014)

One Merlot wine was made using a mixture of ScottLabs Color Pro, Tannin VR Supra (Laffort), and French oak chips.  The other wine was made with a mixture of Zym Color Plus (Enartis), Tan Fermcolor (Enartis), and Tan Color (Enartis).  Both experimental wines were meant to mimic similar enzymatic and tannin additions.  There were no chemical differences between the wines, and sensory testing was not performed in this project.  No resources to measure color or phenolic content were available for this project.

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Extended Maceration on Merlot (2015)

Two merlot wines from identical lots of grapes were separated so that one received 3 weeks of extended maceration while the other was immediately pressed after alcoholic fermentation.  There were no chemical differences between these wines, with a slight increase in VA in the extended maceration. The extended maceration wine had more tannin but less anthocyanin, and slightly more browning. Microbial presence was the same between wines.  There were no significant sensory differences or preferences between wines.

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Leaf Pulling Trial with Petit Verdot (2014)

For one half of a single block of Petit Verdot, leaf pulling was done on the east side of the vines. For the other half of the block, leaf pulling was done on both the east and west sides. The leaf pulling was done approximately one month prior to harvest. There were very little chemical differences between the wines, and no significant sensory differences were found.

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