This study examines the impact that fermenting with whole clusters or with stem inclusion has on Chambourcin wines. Chambourcin grapes were harvested from the same block on the same day and separated into 3 T Bins. One T Bin received 100% destemmed and crushed fruit (control). The second T Bin received 30% whole clusters at the bottom, and then was filled with 70% destemmed and crushed fruit (by weight). The third T Bin received 30% of the stems by weight from the control at the bottom of the T bin, and then were filled with the same weight of destemmed and crushed grapes as the control and treatment. All other treatments between musts and wines were identical. pH was slightly increased by whole cluster and stem inclusion, and TA and tartaric acid was slightly decreased. Pyrazine was slightly increased by the treatments. Color intensity was not much affected by the treatments. Catechin, epicatechin, and quercetin were slightly increased by the treatments. Tannin was increased by the treatments, and anthocyanins were decreased by the treatments. Overall, stem inclusion seemed to result in lower Bitterness, and may have lowered Astringency and Herbaceous/Green character. The whole cluster and the control treatments tended to be higher in Herbaceous/Green character. The intensity for the descriptors for whole cluster inclusion seemed to change over time, perhaps due to ester qualities decreasing over time in bottle. Preference trends were hard to determine, although whole cluster and stem inclusion wines tended to be more preferred over the control.
This study examines the impact that different sources of fermentation tannins will have on the sensory and phenolic qualities of Chambourcin wine. Chambourcin picked at the same time from the same block were crushed and destemmed into four fermentation bins, each with 1.5 tons of grapes. One bin was a control with no exogenous tannin added; the second bind received oak chips and fermentation tannins (Color Max and FT Rouge); the third bin received 75 pounds of Tannat skins; and the fourth bin received oak chips, fermentation tannins, and Tannat skins. All other treatments between lots were the same. In general, adding oak and tannat skins lowered color and phenolic attributes, except that tannin was slightly increased. Adding these compounds seemed to increase catechin and epicatechin. Adding Tannat skins and oak chips together increased catechin and epicatechin and slightly increased color intensity. Descriptors were mixed, and not too many differences could be seen between wines with the descriptors used in this study. In general, judges tended to prefer the Control wine and the wine made with Tannat Skins, Oak Chips, and Tannin added. This study suggests that the effects of adding different sources of tannin are not additive but instead are complex and difficult to predict.
This study examines the impact of aging in new Hungarian oak barrels vs aging in flex tank with Hungarian oak Fans on the chemical and sensory profiles of Chambourcin. Chambourcin wine was split into these vessels with the corresponding treatment. Due to the differences between aging in barrel and flex tank, the wine in flex tank required higher additions of sulfur dioxide. Not many phenolic or chemical differences exist between wines, except the wine aged in flex tank showed higher levels of anythocyanins. Judges found the wines were found to be significantly different (p<0.05), but there were no major preferences for one treatment over the other. There was a slight trend for the flex tank wine to show more Oak Character and less Fruit Intensity. Overall, flex tanks show promise in wine aging, but more work needs to be done to address oxygen ingress and headspace issues, as well as fine-tuning the use of oak adjuncts.
This study examines the impact of a desiccation spray on the chemical and sensory profiles of Chambourcin grapes and wine. One block of Chambourcin was divided so that one section of fruit was sprayed with a potassium bicarbonate desiccant, and another section was not sprayed. The desiccated fruit was sprayed at the beginning of veraison and then weekly for a total of four sprays over four weeks. The fruit was harvested and processed on the same day, and all treatments between the fruit were identical. The desiccation treatment slightly concentrated berry components, although not many differences were found in wine. The desiccation treatment, however, lowered the color intensity and slightly lowered the tannin and anthocyanin content in the wine. Other parameters were not greatly affected. At one tasting, the wines were found to be significantly different (p<0.05), and in general there was a preference for the wine made without desiccation. At another tasting, there was no significant difference between wines, and no major preference trends. More studies on desiccation across vintages would be beneficial to further elucidate the impact of these treatments in Virginia.
This study examines the impact that LalVigne Foliar Spray (ScottLabs) has on the ripeness of Chambourcin grapes. Lalvigne was sprayed at 5% veraison and then 7-9 days later on a 2 acre parcel of Chambourcin at the recommended rate. Control and treatment grapes from the same block were harvested and processed on the same day, fermented separately as 1.5 ton lots in T Bins, and all other treatments between fermentations were kept the same. A third treatment was also added, were 75 pounds of Tannat skins were added to LalVigne-treated grapes at the beginning of fermentation. Although ripening kinetics between each treatment were similar (data not shown), anecdotally, the sprayed berries exhibited more color development. Juice from LalVigne-treated grapes exhibited higher nitrogen numbers (except lower ammonia). Wine produced with Tannat skins added had lower alcohol and pH (58% increase in proton concentration). In general, grapes treated with LalVigne showed increased color intensity and increased amounts of phenolic compounds. The sprayed grapes showed a large increase in Malvidin glucoside but a slightly lower count of monomeric and total anthocyanins. Tannat skins added to the LalVigne sprayed wine showed a smaller increase in color intensity, a larger increase in catechin, epicatechin, gallic acid, and tannin, and a decrease in anthocyanin content. For the triangle test, of 21 people who answered, 9 people chose the correct wine (43%), suggesting the wines were not significantly different. In general, people who answered correctly had a slight preference for the sprayed wine, but this preference was very weak. Descriptive analysis did not show many trends between wines. The control tended to have slightly lower Overall Aromatic Intensity to the sprayed wines, and the wine with Tannat skins seemed to have higher Fruit Intensity. The LalVigne spray wines tended to have slightly higher Herbaceous/Green scores, except for the wine with Tannat added.
This study examined the impact of adding increasing levels of Querplus (oak tannin from Laffort) to Chambourcin Port-style wine on its sensory characteristics. The treatments for this study were no addition, 50ppm addition, 100ppm addition, and 150ppm addition (5g/hL, 10g/hL, and 15g/hL, respectively). All other treatments between wines were kept the same. Because of sugar and ethanol differences between the control and treatment wines (due to mixing effects), the control wine was not tasted. Barrels were not identical between treatments, but 10-year-old barrels were used for each treatment. Adding Querplus did not affect wine chemistry or phenolics. Overall, higher amounts of Querplus were preferred by judges. 150ppm had a slight tendency to increase the perception of Sweetness, and 100ppm tended to increase the perception of Alcohol and Body. Astringency was not very affected by the treatments. None of these impacts were very pronounced, however. More work is needed on the interaction of tannin, ethanol, and sugar in Port-style wines.
This study examines the impact of whole cluster inclusion on the phenolic and sensory characteristics of Chambourcin wines. Chambourcin grapes sourced from the same block were either completely destemmed and lightly crushed (0% inclusion), 70% were destemmed and lightly crushed (30% inclusion), or 50% were destemmed and lightly crushed (50% inclusion). All other treatments between lots were the same. Increasing the amount of whole cluster inclusion tended to lower the ethanol content. Whole cluster inclusion tended to lower the color intensity and increase the hue, and this effect was more pronounced for higher levels of inclusion. All phenolic indices were lowered by whole cluster inclusion, but did not differ much between 30% and 50% inclusion. This was most noticeable with monomeric and total anthocyanins, as well as malvidin glucoside. Overall, whole cluster inclusion tended to increase Herbaceous/Green character in the wines. Descriptions of these wines were mixed, and most trends were weak and varied from tasting to tasting. No major preference trends could be seen across tastings. This study suggests that whole cluster inclusion could be a viable stylistic tool for Chambourcin wines, but much more work is needed to elucidate what impacts these kinds of treatments have on wine quality.