The Impact of Trellising on Ripening and Quality in Merlot (2017)

Different trellising systems can have a large impact on canopy sun exposure, leaf area:fruit ratios, and yields. Different trellising systems also have different labor requirements for proper management. Determining which trellising system is best for a given site, on a given variety, is therefore very important. This study examines the difference between two training methods – VSP and Scott Henry – on resulting juice and wine quality. Merlot (clone 181) was planted in 2000 and trained as Scott Henry. In 2017, every other row of this block was converted to VSP. All vineyard treatments were identical, with leaf pulling on east side of vine after fruit set. Grapes were harvested on the same day, and all fermentation practices were identical between treatments. There were not many differences in juice and wine chemistry, except for slightly lower tartaric acid in the Scott Henry wine and decreased acidity. Tannin may have been slightly lower in the Scott Henry wine as well. Overall, these wines were not found to be significantly different, but perhaps would have been at more lenient p levels. Descriptive analysis was not completely consistent between tastings. Preferences slightly favored the VSP trellis, but this was not strong. This study should be repeated over multiple years on different grape varieties. More careful attention should be paid to viticultural parameters, such as leaf area to fruit weight ratios, and yield parameters.

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Central Virginia Cabernet Franc Terroir Investigation (2017)

The purpose of this study is to evaluate the difference in wine quality and chemistry based on vineyard site and winemaking style using Cabernet Franc grapes grown in and around the Monticello Wine Trail appellation. This purpose was achieved through comparing the impact of growing area on wine style (by comparing how wines from different vineyard sites taste when produced by the same winemaker) as well as comparing different winemaking stylistic impacts on grapes from different regions (by tasting grapes from the same region being produced by different winemakers). Three winemakers traded their grapes to each other and fermented each other’s grapes according to their own stylistic practices. The results of this study suggest that winemaking practices are able to substantially impact many of the vineyard effects on wine chemistry. Wines produced at Veritas tended to be positively correlated with Tannin and either negatively correlated to Total Anthocyanin, or not correlated with Anthocyanin (Veritas Winery Veritas Grapes). Wines produced at Early Mountain Vineyards, on the other hand, were generally correlated to Total Anthocyanins and negatively correlated to Tannin. Horton winery tended to produce wines which were in-between the Veritas and Early Mountain wines, in many of these regards. Overall, these results suggest that while vineyard site places some boundaries on the chemical qualities of wine, chemical qualities can be easily driven by winemaking practices. However, vineyard site tended to have the greatest impact on sensory characteristics. Early Mountain grapes tended to have more Herbaceous and Acidic qualities, and Veritas grapes tended to have higher Fruit Intensity and Astringency. Horton grapes tended to have higher Overall Aromatic Intensity. However, winemaking practices were able to alter these sensory characteristics in some cases, so that there was not a simplistic division of vineyard sites into certain flavor profiles. Most parameters were not dominated by either winemaking or vineyard site, but a mixture of both was seen. In the future, many more studies should be performed, with more statistical rigor.

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Clonal Assessment of Cabernet Franc (2017)

This study examines the clonal differences between Cabernet Franc clones 214 and 327. Grapes were harvested separately on October 4, 2017. Must was inoculated with ES488 and was pressed off after around 18-19 days of maceration. Both wines received the same additions, and all other treatments were identical between wines. Clone 327 tended to have higher berry weight and cluster weight, although yield was slightly lower. Grape chemistry suggests that clone 214 had lower tannin and phenolics, but slightly higher anthocyanins. Juice and wine chemistry did not differ too much. Clone 214 wine tended to have slightly higher phenolic parameters, although these differences were weak. It is possible, then, that although Clone 214 had lower levels of phenolic compounds (except anthocyanin), phenolic compounds were more extractable from these grapes. However, Clone 214 received an addition of Lafase HE Grand Cru which Clone 327 may not have received, and this may have impacted the results as well. Overall, the wines were not found to be significantly different via triangle testing. Descriptive analysis did not yield any consistent trends between tastings. There may have been a slight preference for Clone 327, but this was weak. More work should focus on the sensory and chemical differences between wines produced from these clones, but more work should also be done to better distinguish viticultural characteristics between these wines, as well.

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The Impact of Soil Conductivity on Petit Verdot Ripeness and Wine Quality in VSP Trellising (in collaboration with Bubba Beasley) (2017)

This study attempts to quantify the impact of soil conductivity on VSP-trained Petit Verdot juice and wine chemistry, as well as on the sensory qualities of wine. Soil conductivity was determined by EM mapping performed by Bubba Beasley, in order to find areas of low and high conductivity within the vineyard block. The low conductivity soil had a low rock content, and the high conductivity soil had high rock content (75%, shale). Then, fruit from each conductivity region was harvested on the same day but kept separate and destemmed into two T Bins: One for low conductivity fruit, and the other for high conductivity fruit. Fermentations were punched down twice per day, and all other treatments between wines were identical. Yield and viticultural parameters suggest an ESVC:CW index of 1.2 for both the low conductivity and high conductivity. Acidity and potassium was higher in the high conductivity juice. Indeed, soil pH was found to be negatively correlated to petiolar potassium and positively correlated to fruit pH. Petiolar potassium was also found to be positively correlated to juice potassium. Wine made from higher conductivity grapes had higher acidity and lower potassium. The high conductivity treatment had slightly lower anthocyanin and tannin measures. These results, overall, suggest that the lower conductivity wine had generally “riper” characteristics. These results would not be expected, as the higher conductivity soil (with higher rock content) would be expected to have less total available water in the soil for the grapevines to use. It would be more expected, therefore, that the high conductivity vine would have had less water, and thus potentially more “ripe” chemistry characteristics. Overall, the wines were not found to be significantly different at tastings. There may have been a slight preference for the low conductivity wine, but if so it was very weak. There were slight tendencies for the high conductivity treatment to have higher Acidity and Bitterness, and slightly lower Body. These further suggest a less “ripe” wine was produced at the high conductivity block. This study should be repeated over multiple vintages in order to determine whether these results are replicable.

This study should be read with its companion study in Ballerina trellising.

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The Impact of Soil Conductivity on Petit Verdot Ripeness and Wine Quality in Ballerina Trellising (in collaboration with Bubba Beasley) (2017)

This study attempts to quantify the impact of soil conductivity on ballerina-trained Petit Verdot juice and wine chemistry, as well as on the sensory qualities of wine. Soil conductivity was determined by EM mapping performed by Bubba Beasley, in order to find areas of low and high conductivity within the vineyard block. The low conductivity soil had lower soil rock content (10%, channers), and the high conductivity soil had higher rock content (50%, shale). Then, fruit from each conductivity region was harvested on the same day but kept separate, and destemmed into two T Bins: One for low conductivity fruit, and the other for high conductivity fruit. Fermentations were punched down twice per day, and all other treatments between wines were identical. Average berry weight and cluster weight were slightly higher in the high conductivity treatments. Yield and viticultural parameters suggest an ESVC:CW of 1.7 and 1.9 for the low conductivity and high conductivity, respectively. Juice Brix and potassium was lower, and acidity and nitrogen were higher in the high conductivity treatment. These differences transferred through to wine chemistry. The high conductivity treatment seemed to have lower levels of phenolic compounds, and lower color. These results, overall, suggest that the lower conductivity wine had generally “riper” characteristics. These results would not be expected, as the higher conductivity soil (with higher rock content) would be expected to have less total available water in the soil for the grapevines to use. It would be more expected, therefore, that the high conductivity vine would have had less water, and thus potentially more “ripe” chemistry characteristics. Overall, these wines were not found to be significantly different in triangle testing. No preference trends could be seen. Additionally, descriptive analysis results were inconsistent between tastings, and no general trends can be seen except perhaps that the high conductivity wine had slightly lower Body. In the future, this study should be repeated over multiple vintages, on different grape varieties, and at different sites.

This study should be read with its companion study in VSP trellising.

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Sauvignon Blanc Clonal Investigation (2016)

This study examines the clonal differences between Sauvignon Blanc FPS 1, FPS 18, ENTAV 376, and ENTAV 241 planted in the same year in the same vineyard block. Grapes were harvested and pressed on the same day but kept separate, and all treatments between lots were kept the same. Yields were different between some clones, and the FPS clones tended to have higher malic acid and YAN. Clone 241 tended to have lower acidity and higher pH than the other clones, and the opposite trend was observed for FPS 1. Wines produced from FPS 1 and ENTAV 376 had the highest levels of 3-MH. Descriptive analysis found several differences between clones. Wine made with ENTAV 376 was highest in most sensory descriptors, and most people preferred Clone 376. However, these differences may not all be clonal, but could be due to variations between fermentations. As such, this study should be repeated in order to determine if clone 376 is truly much more aromatically intense.

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Influence of Soil Conductivity on Vineyard Maturity in Cabernet Franc (2014)

Soil electromagnetic conductivity may give information regarding soil drainage, salt composition, nutrient density, and texture.  High electrical conductivity correlates to high cation exchange capacity, and is often found in drier soils (due to less salt leaching) or clay soils.  Electromagnetic conductivity soil mapping was conducted on different vineyard blocks, and Cabernet Franc blocks of low and high conductivity were harvested separately but on the same day and processed identically.  There were no chemical differences between wines, and sensory results were not significant.  However, the trace metal content of the wines were different.

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Influence of Soil Conductivity on Vineyard Maturity in Merlot (2014)

Soil electromagnetic conductivity may give information regarding soil drainage, salt composition, nutrient density, and texture.  High electrical conductivity correlates to high cation exchange capacity, and is often found in drier soils (due to less salt leaching) or clay soils.  Electromagnetic conductivity soil mapping was conducted on different vineyard blocks, and Merlot blocks of low and high conductivity were harvested separately but on the same day and processed identically.  Although laboratory analyses showed little differences between the wines, sensory analysis revealed significant differences between these wines, with a preference for wines made from high conductivity soils.

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