Harvest Decisions Based on Grape Phenolic Development (Enartis) (2017)

This study examines the ability to judge when grapes are harvest-ready by monitoring phenolic development over time. Cabernet Franc grapes began being sampled weekly starting on September 1 for a number of chemical and phenolic parameters. Enartis then made a harvest recommendation for September 22 (First Pick) based on comparing phenolic and chemical profiles over time. This decision was based on declining anthocyanin and phenolic values occurring in the grapes, with a desire to pick while these values were near their peak. The winemaker monitored grapes based on in-house chemistry values, seed coloration, and hang time, and picked another portion of the block on October 4 (Second Pick). Because the chemistry was different between juices, the second pick juice received more tartaric and malic acid additions. All other treatments were the same, except for a possible non-addition of Lafase HE Grand Cru to the second pick must. Wines were pressed off after 18-19 days. Grape ripening tended to follow classic ripening curves, exhibiting increasing Brix and a positive sigmoidal pH ripening curve. Average berry weight and water content peaked and then declined, due to dehydration. Phenolic content tended to peak and decline as well, and this occurred after the berry weight and water content began to decline. The first pick, based on phenolic ripeness, had lower alcohol. The differences in lactic acid may have been due to different malic acid additions between treatments. The first pick wine had slightly higher tannin and anthocyanin and much higher quercetin glycosides, but slightly lower color. However, this wine received Lafase HE Grand Cru, whereas the second pick wine may not have received this enzyme. This may have altered the results in this regard. Overall, sensory analysis suggests that these wines were significantly different. There tended to be a preference for the earlier picked wine, but this preference was tasting-dependent. Descriptive analysis was inconsistent between tastings, and no conclusions can be drawn with regard to this. Due to this inconsistency, this study should be repeated multiple times to help gauge the impact of picking based on phenolic parameters on sensory qualities in wine. Additionally, the use of Lafase HE Grand Cru in one wine and perhaps not in the other could have further confounded these results, suggesting that this study should be repeated. However, the idea behind this technique of monitoring ripening may serve to be a useful guide to picking in Virginia, to harvest while phenolic levels are maximized before they begin to decrease.

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Reducing Green Character with Yeast Strains (Enartis) (2017)

This study examines the impact of different yeast strains on green character in Cabernet Franc. Cabernet Franc grapes were harvested and processed on the same day into 3 separate T Bins. Each T Bin received 25ppm sulfur dioxide and were then inoculated with either CSM (ScottLabs), D254 (ScottLabs), or D20 (Enartis). D20 yeast may reduce green character through higher fermentation temperatures blowing off pyrazine (Enartis 2018), therefore this T bin was fermented in the sun. CSM was chosen because it is also marketed as being able to reduce green character (Scott Laboratories 2018), but since it did not specify a higher fermentation temperature, this treatment was not fermented in the sun. Each T Bin was punched down twice per day and pressed on the same day for 9 days of maceration. All other treatments between wines were identical. All yeast strains had similar fermentation kinetics, with D20 perhaps being slightly warmer. Wine chemistry was similar between treatments, except that IBMP was slightly lower in the D20 yeast treatment. There were no strong trends for the descriptors used in this study. There was a slight trend for the CSM wine to have higher Fruit Intensity, and for the CSM and D20 wines to have higher Astringency. There was a slight preference for the D254 wine.

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No Sulfur Winemaking in Chardonnay (2017)

This study examines the effect of fermenting wine with and without sulfur dioxide. Chardonnay grapes were harvested and pressed into 3 separate tanks. At pressing, one treatment received 3g/hL sulfur dioxide (control), and the other did not receive any sulfur dioxide, and the third did not receive any sulfur dioxide and received Stab Micro M and Tan Blanc at pressing and followed an Enartis no sulfur winemaking protocol. After settling, the juices were racked into barrel and inoculated with CY 3079. The Enartis wine received additions of Claril SP during settling. After completion of malolactic conversion, the control wine was stabilized with sulfur dioxide, and the Enartis treatment had Stab SLI, Tan SLI, and Stab Micro added at the end of malolactic conversion. Both barrels with the Enartis treatment fermented slower than the rest. No major chemistry differences were found between wines except for slightly lower lactic acid in the Enartis wine. The no sulfur wine had slightly higher levels of Lactic Acid Bacteria, slightly less O. oeni, and slightly less S. cerevisiae. The Enartis wine had slightly more S. cerevisiae, and slightly higher diacetyl. In general, judges were able to distinguish between the wine made with and without sulfur dioxide. This may have been due to a perceptible difference in diacetyl between these two wines, likely due to diacetyl binding by sulfur dioxide in the wine produced with sulfur dioxide. The no sulfur wine treatment may have had slight oxidation (but not in a negative respect), and the Enartis no sulfur wine may have had a slight bitterness (although this was not examined statistically). A perceived bitterness in the Enartis wine may be due to the use of sacrificial tannin. Preferences were not strong, but there seemed to be a preference for the wine made with sulfur dioxide, and then perhaps followed by the wine made without sulfur dioxide. However, many more studies are needed to further qualify how no sulfur winemaking impacts wine sensory qualities. Additionally, more studies need to be performed to determine how no sulfur wines age over time.

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No Sulfur Winemaking in Cabernet Franc (2017)

This study examines the effect of producing wine with and without sulfur dioxide. Cabernet Franc grapes were harvested and processed into 3 separate T Bins. During crush, one treatment received 25ppm sulfur dioxide (control), the second did not receive any sulfur dioxide but instead was protected at crush with Zymaflore Egide, and the third did not receive any sulfur dioxide but instead received Tan Rouge and Stab Micro M during crushing and followed an Enartis no sulfur winemaking protocol. After processing, all wines were inoculated with ES488. One-third through fermentation the Enartis treatment received additions of Pro Tinto and Tan Color. Both no sulfur treatments were inoculated with ML Silver after pressing. At the end of fermentation, the control wine was stabilized with sulfur dioxide, the no sulfur wine received Stab Micro, and the Enartis protocol received additions of Surli Round, Tan SLI, and Stab Micro M. Wine chemistry is similar between treatments, except that no sulfur winemaking resulted in slightly lower TA. Both no sulfur winemaking wines had higher levels of acetic acid bacteria, lactic acid bacteria, and Pediococcus. Color intensity was higher due to a lack of sulfite bleaching. Overall, Cabernet Franc produced with sulfur dioxide tended to have higher perceived Acidity. Other differences between wines were not easy to distinguish with the descriptors used in this study, but the no sulfur wine and the wine with sulfur dioxide may have had slightly higher Overall Aromatic Intensity and Fruit Intensity. The wine made with sulfur dioxide tended to be most preferred, followed by the wine without sulfur dioxide. Conclusions are difficult to draw at this point. Many more studies are needed on no sulfur winemaking in red wines and its impact on sensory qualities. Additionally, more studies are needed to examine how aging is affected by no sulfur winemaking.

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The Impact of Yeast Fining on Wine Quality Prior to Bottling (Enartis, Laffort) (2017)

This study examines the impact of different yeast fining techniques on finished wine quality. A 2017 red wine blend (75% Cabernet Franc, 25% Petit Verdot) was blended into tank in early February. Then, on February 8 the wine was split into four analogous neutral barrels, and the barrels either received no treatment (control), a BM45 yeast addition at 1g/L, a Surli Velvet (Enartis) addition at 0.05g/L, or an Oenolees (Laffort) addition at 0.4g/L. The barrels were stirred on the date of addition and a week later. The wine was pulled for analysis and bottle samples on March 15. There were no differences in wine chemistry and color. For the descriptive analysis, there were no strong trends for the descriptors used in this study. There was a slight tendency for the BM45 treatment to have higher Fruit Intensity, Overall Aromatic Intensity, and Body and lower Herbaceous/Green character. Oenolees had a slight tendency for lower Fruit Intensity and Bitterness. Surli Velvet had a slight tendency towards higher Herbaceous/Green character and Astringency. Many of these differences were not very pronounced, however, and many judges commented that differences were slight. All wines were equally preferred, more or less. Some judges remarked that the BM45 treatment seemed to have a larger effect on the mouthfeel than the rest. More studies are needed in order to better quantify the impacts of these treatments on wine flavor and aroma quality.

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Enhancing Color Stability of Norton with Different Enological Fermentation Tannin (2017)

This study examines the impact of adding different kinds of exogenous tannin prior to fermentation in Norton grape must. Norton grapes were harvested on the same day and destemmed into four T bins. The T bins then received the following treatments: 1) No tannin addition (control), 2) Tan Color (Enartis) addition at 180g/ton followed by Pro Tinto addition (150g/ton) partway through fermentation (mostly condensed tannins), 3) FT Rouge (ScottLabs) addition at 60g/hL (hydrolysable tannin), and 4) a series of BSG product additions: UVA V-Tan at 30g/hL, Premium Limousin at 15g/hL, and Premium Color at 15g/hL (mix of condensed and hydrolysable tannins). All other treatments between wines were equal. After approximately two weeks, wine was pressed off. The BSG wine and the FT Rouge wine had slightly slower fermentations. Wines had slightly differing alcohol contents (slightly higher when using condensed tannin, and slightly lower when using hydrolysable tannin), but otherwise no major chemistry differences were seen. No color differences can be seen. The addition of these products may have slightly lowered caftaric acid and increased epicatechin and gallic acid, and these increases were more correlated to products containing condensed tannin. No major tannin or anthocyanin differences could be seen. For the descriptive analysis, there were no strong trends for the descriptors used in this study. There were slight trends for the control to have lower Fruit Intensity, Astringency, and Body. The wines made with BSG products tended to have higher Fruit Intensity, Overall Aromatic Intensity (along with FT Rouge in this regard), Bitterness, Astringency, and Body. The Pro Tinto/Tan Color and FT Rouge treatments were relatively similar and often fell in-between the Control and BSG products, except for FT Rouge with Overall Aromatic Intensity (where it was higher) and for Pro Tinto/Tan Color with Herbaceous/Green quality. In general, there was a preference for the wine produced with BSG products; however, judges thought that the wines were all fairly similar. In the future, more studies should be performed with these products on different grape varieties.

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The Effect of Tan Citrus on Chardonnay (2016)

This study compares Chardonnay wine fermented either with or without the enological tannin Tan Citrus (Enartis) added before primary fermentation. When combined with yeast with β-glycosidic activity, this tannin may increase fruit and floral aromas in wine. The yeast used in this study was CY3079. No major chemical differences were found between wines. The wines were not significantly different. There was a very slight preference for the wine made with Tan Citrus. More work is needed on the enological additive to effectively evaluate its impact.

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The Effect of Tan Citrus on Petit Manseng (2016)

This study compares Petit Manseng wine fermented either with or without the enological tannin Tan Citrus (Enartis) added before primary fermentation. When combined with yeast with β-glycosidic activity, this tannin may increase fruit and floral aromas in wine. The yeast used in this study was 58W3, a glycosidic yeast. No major chemical differences were found between wines. Wines made with Tan Citrus had higher tannin content and slightly lowered grape reaction product, which may suggest that Tan Citrus helped protect the wine against oxidation. Triangle sensory testing revealed that the wines were significantly different (p<0.001). No major sensory trends could be seen with the descriptors used in this study, and judges were split on which wine they preferred.

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Tan Elegance in Chardonnay (2015)

This study compared the chemical and sensory attributes of Chardonnay with and without the addition of Tan Elegance (Enartis).  The wine with Tan Elegance had lower titratable acidity, but all other chemical attributes were the same.  There was a  significant sensory difference between wines, with a slight preference for the wine without Tan Elegance.

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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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