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.
This study examines the impact of whole cluster fermentation versus more traditional fermentation techniques in Petit Verdot winemaking. Petit Verdot grapes were harvested and processed into two T Bins. One treatment was completely destemmed, whereas the other treatment was 100% whole cluster inclusion. The 0% inclusion treatment was punched down, whereas the whole cluster treatment was stomped for punchdowns. When the 0% treatment reached approximately 8 Brix, the fermenting wine was delestaged and the pomace was stomped, and the wine was then racked back into the stomped pomace. Wine was pressed 16 days after processing. Juice and wine chemistry were very similar between treatments, except TA was slightly lower in the whole cluster treatment. Color was slightly increased, and many phenolic compounds were increased by whole cluster inclusion. Although anthocyanin was lower from whole cluster treatment, polymeric anthocyanins were increased. Overall, these wines were not found to be significantly different. There may have been a slight preference for the whole cluster wine. The whole cluster wine tended to score higher in Bitterness, Astringency, and Fruit Intensity. The whole cluster inclusion treatment had the clusters stomped during T Bin filling, which may have reduced some of the more estery characteristics often seen in whole cluster winemaking. Thus, these results may be more in line with what would be expected with a stem inclusion wine, rather than a purely whole cluster wine. This study suggests that whole cluster inclusion may be a useful method for creating a Petit Verdot which could serve as a valuable blending component, but more studies on whole cluster Petit Verdot are needed to determine whether any strong trends can be seen between treatments over time.
This study examines the impact of whole cluster inclusion on Cabernet Franc wines. Cabernet Franc grapes were harvested and processed into T bins. One T bin received 100% destemmed grapes, and the other received 100% whole clusters. The destemmed treatment was punched down twice daily, and the whole cluster treatment was stomped. After 18 days of maceration, wines were pressed off. The whole cluster wine fermented slower than the destemmed wine. Ethanol content, potassium, and lactic acid were also higher in the whole cluster wine. Color and anthocyanin were lowered in the whole cluster wine, while catechin and gallic acid were increased. Tannin may have slightly increased in this wine as well, but this is a weak result. For the triangle test, of 26 people who answered, 11 people chose the correct wine (42%), suggesting that the wines were not significantly different. In general, people who answered correctly did not show strong preferences for one wine over the other. For the descriptive analysis, there were no strong trends for the descriptors used in this study.
This study examines the effect of adding fining agents to hyperoxidized Petit Manseng juice on the sensory and phenolic characteristics of Petit Manseng. After reducing the temperature to 10-12°C, Petit Manseng juice was hyperoxidized by pumping four volumes of juice over a sump screen, taking about 10 minutes. After this process, juice was very brown and then sulfur dioxide was added at 50ppm. Juice was then split into two vessels, one of which was fined with casein, PVPP, and bentonite to remove solids and phenolic compounds. All other treatments between juices and wines were identical. Overall, no major chemical, color, or phenolic differences were observed between the wines, suggesting that fining juice after hyperoxidation does not do much to alter the color and phenolic properties of the wine. Triangle testing suggests that the wines were significantly different from each other (p<0.001), likely due to a difference in turbidity. No preferences could be seen for one wine over the other. The fined wine had a slight tendency for lower Tropical Fruit and increased Bitterness/Astringency.
This study examined the impact of 5 winemaking techniques on the phenolic composition of Merlot. The treatments were as follows: 1) Control, 2) Stomping grapes during a delestage (otherwise identical to control), 3) Lafase Grand Cru (Laffort) at crush, 4) VR Supra (Laffort) at crush, and 5) Both Lafase Grand Cru and VR Supra at crush. All other treatments were the same between wines. All wines had a delestage operation performed at 2 Brix, where stomping occurred for the stomping treatment. There were no major chemical differences between wines. Stomping had very little effect on phenolic chemistry. VR Supra and Grand Cru alone increased color, but when combined color was lowered (corresponding to lower anthocyanins). No other impacts on phenolic qualities could be observed, except tannin was increased and gallic acid decreased in the wine treated with VR Supra. The sensory impact of the VR supra treatment cannot be adequately assessed due to it being an outlier. Overall, the treatments tended to slightly increase Fruit Intensity and Body relative to the Control. The stomped wine tended to be the most preferred wines for all but the May 3 Tasting. Grand Cru + VR Supra also tended to be regarded fairly highly. The Control wine tended to be the least preferred. These results were not very strong, however, and more studies on the impacts of these treatments on the chemical and sensory qualities of wine should be performed. Additionally, more work should be done to examine the impact of these treatments on wine during aging.
This study compared the chemical and sensory effect of bottling Pinot Gris wine with Saranex and Saratin screw cap closures. No significant chemical or sensory differences were determined between wines; however, the amount of time in bottle storage (less than 4 months) may not have been enough to result in an effect. There seemed to be a slight preference for Saranex.
Syrah was vinified with 0% whole cluster inclusion, 25% whole cluster inclusion, and 75% whole cluster inclusion. No real chemical differences were observed between wines. Whole cluster wines tended to have higher tannin content but lower anthocyanin content. This corresponded to a lower level of color intensity in those wines as well. Most people preferred the 25% whole cluster inclusion, and most people did not prefer the 75% whole cluster inclusion.
In a single block of Pinot Gris, one half of clusters were cut in half following the completion of veraison. The berries that had undergone cluster halving exhibited more sugar accumulation, but had less tartaric acid. The wines, however, were not very different. No significant sensory differences were found between wines.