The Impact of Adding Chardonnay Lees to Aging Red Wine (2017)

This study examines the impact of adding chardonnay lees to aging Cabernet Franc wine on mouthfeel and aroma. Cabernet Franc wine was cleanly racked into 3 separate, identical barrels on December 29, 2017 so that very little lees were transferred. Then: 1) one barrel received no addition of Chardonnay lees, 2) one received 1 liter of Chardonnay lees, approximately 1.02E6 cells/mL (Low NTU), and 3) one received 3 liters of Chardonnay lees, approximately 3.06E6 cells/mL. Lees were light lees, harvested from Chardonnay wines fermented with D254. The yeast in the lees were budding under microscope, and so 90ppm of sulfur dioxide was added to the lees before adding to barrel. The wines were stirred once every two weeks until taken for sampling in late March, 2018. No major wine chemistry differences were apparent between treatments. Sulfides were all similar between wines, with some differences in Dimethyl Sulfide. Microbial cell counts were generally higher in wine with lees additions. Color intensity was slightly lower in wine with lees added. Phenolic profiles were very similar, with perhaps a slight decrease in tannin with lees addition. Overall, low lees addition had a slight tendency to increase Fruit Intensity. Lees addition in general seemed to slightly lower Astringency. However, many of these differences were weak, and differed between tastings. The lees addition wines were generally more preferred over the control wine. This suggests that lees addition to red wines can be of benefit to red wine quality. More research with more rigorous sensory analysis is needed to further clarify what aspects of wine sensory characteristics are impacted by lees addition.

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Comparison of Reverse Osmosis to Chaptalization in Press Fraction Chardonnay (2017)

The purpose of this study is to compare reverse osmosis treatments of juice to reverse osmosis treatments on wine, traditional chaptalization techniques, and no treatments at all. These techniques are commonly used in the wake of heavy rainfall events forcing winemakers to pick early. Chardonnay grapes were harvested and pressed into tank. This press fraction juice was allowed to settle overnight, and then was split into three separate lots: 1) Control, 2) Chaptalized, and 3) Reverse Osmosis Before (ROB) Fermentation. The ROB juice was concentrated 15%. After fermentation and malolactic conversion, the control lot was split into two separate barrels, and one of these received another treatment: 4) Reverse Osmosis After (ROA) Fermentation and malolactic conversion, to concentrate 15%. The juice chaptalization treatment was increased by 0.5 Brix in order to produce a potential alcohol which would mimic the ROA alcohol concentration, as opposed to the ROB alcohol concentration. Wines were bottled for the WRE right after the ROA treatment in early January. All other treatments between lots were equal. Alcohol content was highest in the ROB treatment. The ROB wine also had decreased acidity and increased pH, whereas the Chaptalized wine and the ROA wine had slightly increased acidity. Reverse osmosis may have increased the perception of Alcohol, Fruit Intensity, and other descriptors in wine relative to chaptalized wines. Generally, reverse osmosis wines were preferred to the chaptalized wine, but this may have been due to some oxidation in the chaptalized wine.  This study should be read in comparison with its sister study on free run Chardonnay.

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Comparison of Reverse Osmosis to Chaptalization in Free Run Chardonnay (2017)

The purpose of this study is to compare reverse osmosis treatments of juice to reverse osmosis treatments on wine, traditional chaptalization techniques, and no treatments at all. These techniques are commonly used in the wake of heavy rainfall events forcing winemakers to pick early. Chardonnay grapes were harvested and pressed into tank. This free run juice was allowed to settle overnight, and then was split into three separate lots: 1) Control, 2) Chaptalized, and 3) Reverse Osmosis Before (ROB) Fermentation. The ROB juice was concentrated 15%. After fermentation and malolactic conversion, the control lot was split into two separate barrels, and one of these received another treatment: 4) Reverse Osmosis After (ROA) Fermentation and malolactic conversion, to concentrate 15%. The juice chaptalization treatment was increased by 0.5 Brix in order to produce a potential alcohol which would mimic the ROA alcohol concentration, as opposed to the ROB alcohol concentration. Wines were bottled for the WRE right after the ROA treatment in early January. All other treatments between lots were equal. The ROB wine had higher alcohol content than the other wines. Lactic acid was slightly higher in the ROA wine, which also had a higher TA. The sensory results suggest that reverse osmosis can increase the perception of alcohol in wine, as well as increase acidity and other descriptive parameters. Reverse osmosis wines were generally preferred over the chaptalized wine, but this may have been due to reduction being present in the chaptalized treatment. More studies are needed to better elucidate the impact of RO on the aromatic and mouthfeel qualities of wine.  This study should be read in comparison to its sister study on press fraction Chardonnay.

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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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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 Juice Turbidity on Aroma Development in Chardonnay (2016)

This study compares the effects of fermenting Chardonnay juice at a low turbidity, medium turbidity (110NTU), and high turbidity (225 NTU). Juice from the same pick of Chardonnay was settled and racked into barrels. Turbidity was adjusted by adding back fine lees to the juice. All other treatments between wines were the same. The 110 NTU and 225 NTU wines had no chemical differences. The wines were not found to be statistically different at tastings, and those who were able to correctly distinguish the wines had a slight tendency to prefer the wine made from higher turbidity. This wine had a slight trend to be higher in Overall Aromatic Intensity and lower in Bitterness. More work is needed here to obtain a better understanding of the effect of juice turbidity on wine quality. It may be that the turbidity difference in this study was too small to have a great effect on the wine flavor profile.

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ScottLabs IONYS WF Yeast Trial on Chardonnay (2016)

This study examines the impact of IONYSWF yeast (Lallemand) on Chardonnay wine when compared to fermentation with CY3079. Chardonnay juice was settled and split into separate barrels, inoculated with either CY3079 or IONYSWF. Although the IONYSWF fermentation proceeded much slower, not many chemical differences could be seen between the different yeast strains, except that the pH and TA of the IONYSWF – fermented wine was slightly higher. The lower level of free sulfur dioxide in CY3079 suggests a slightly higher production of sulfur dioxide-binding compounds. These results suggest that people are able to tell a difference between Chardonnay wine produced with IONYSWF yeast and wine produced from CY3079. People often preferred wine produced with IONYSWF yeast, likely due to its tendency to enhance Fruit Intensity, Overall Aromatic Intensity, Depth of Flavor, and Body. Although the yeast is marketed to increase acidity, this was not observed in this study. This yeast shows promise with regard to aromatic development in Chardonnay, but more studies are needed to confirm this.

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Chardonnay Lees Management with Extralyse (ARC) (2016)

This study examined the impact of lees stirring and batonnage enzyme addition during Chardonnay aging on the chemical and sensory qualities of the wine. Chardonnay juice was fermented in barrels, and afterwards 3 different stirring regimes were imposed: unstirred, stirred, and stirred with Extralyse (Laffort). Stirring occurred once per week for 8 weeks. The finished wines showed decreasing levels of residual sugar with stirring and with enzyme addition. Some malolactic fermentation could be observed in the stirred wine with Extralyse as well. Wine tended to become more cold stable over time, but the unstirred wine showed the highest level of cold stability but also the highest level of bentonite addition necessary to become heat stable. These results suggest that stirring may enhance Sweetness, Depth of Flavor, Yeast Character, and Body, although many of these effects were weak. The effect of Extralyse in combination with stirring was not too different than from stirring itself. However, the stirring regime for this study was relatively short (8 weeks). In the future, more realistic stirring regimes should be implemented to see whether differences tend to increase over time, particularly with respect to Extralyse.

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Chardonnay Lees Management with Extralyse (ARC) (2016)

This study examined the impact of lees stirring and batonnage enzyme addition during Chardonnay aging on the chemical and sensory qualities of wine. Chardonnay juice was fermented partially in tank before being aeratively racked with lees inclusion to finish fermentation in barrels, and afterwards 2 different stirring regimes were imposed: unstirred and stirred with Extralyse (Laffort). Stirring occurred once per week for 8 weeks. No major chemical differences could be observed between treatments, and both wines underwent partial malolactic conversion. Wines tended to become more cold stable and heat stable over time, with stirring and Extralyse potentially making the wine slightly more heat stable than not stirring. Of 10 judges, 9 were able to correctly distinguish the wines from each other, showing that these wines were significantly different (p<0.001); however, this may have been because the stirred wine was cloudy. 8 out of 8 people tended to prefer the wine with Extralyse; however, the unstirred wine may have had some oxidized characteristics. Wine produced with Extralyse and Stirring had a strong tendency to be higher in Sweetness and Body, and tended to have slightly higher Yeast Character and Depth of Flavor. However, the stirring regime for this study was relatively short (8 weeks). In the future, more realistic stirring regimes should be implemented to see whether differences tend to increase over time.

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Chardonnay Lees Management (2016)

This study examined the impact of lees stirring during Chardonnay aging on the chemical and sensory qualities of the wine. It is a companion study to Blenheim’s Chardonnay Lees Management with Extralyse (ARC) study (2016). Chardonnay juice was fermented in sets of barrels, after which one was left unstirred while the other was stirred during aging. Stirring occurred once per week for 8 weeks. No major chemical differences could be observed between the finished wines. Wine tended to become more cold stable over time, but the unstirred wine required the lowest bentonite addition to become heat stable. Additionally, increasing bentonite additions to become heat stable were necessary after aging. This study suggests that stirring has a noticeable effect on finished wine, but this effect is not necessarily preferred or disliked (perhaps a slight preference towards stirred wines). The descriptors used generally did not help elucidate which qualities in wine were affected by stirring. Some trends seemed to result from stirring, such as a potential increase in body, yeast character, and depth of flavor. Bitterness may have been slightly decreased as well. However, no firm conclusions can be drawn in these regards. The stirring regime for this study was relatively short (8 weeks). In the future, more realistic stirring regimes should be implemented to see whether differences tend to increase over time.

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Chardonnay Lees Management with Extralyse (ARC) (2016)

This study examined the impact of lees stirring and batonnage enzyme addition during Chardonnay aging on the chemical and sensory qualities of the wine. It is a companion study to Blenheim’s Chardonnay Lees Management (2016), which compared the effects of not stirring Chardonnay to stirring Chardonnay. Chardonnay juice was fermented in barrels, and afterwards two different treatments were imposed: stirred, and stirred with Extralyse (Laffort). Stirring occurred once per week for 8 weeks. No major chemical differences could be observed between the finished wines. Wine tended to become more cold stable over time. Additionally, increased bentonite additions to become heat stable were necessary after aging. In general, people often could not distinguish between stirring and stirring with Extralyse. When people could distinguish, there appeared to be a slight preference for wine made with Extralyse. The descriptors used generally did not help elucidate which qualities in wine were affected by stirring. There may be a small tendency for Extralyse to enhance Fruit Intensity and Depth of Flavor, but these tendencies were weak. However, the stirring regime for this study was relatively short (8 weeks). In the future, more realistic stirring regimes should be implemented to see whether differences tend to increase over time.

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Screw Cap Closure Comparison (2015)

The effect of three different Amcor Stelvin screw caps with different oxygen transfer rates on bottled Chardonnay wine were compared in this study.  The chemical parameters measured in this study did not show much differences; however in general tasters preferred the screw caps with lower oxygen transfer rates.  The length of time from bottling to tasting and analysis, however, may have been too short to truly distinguish differences.

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Yeast Nutrient Comparison in Chardonnay (2015)

The effects of the yeast nutrients Go Ferm, Fermaid O, and Fermoplus DAP Free on fermentation kinetics, wine chemistry, wine microbiology, and wine sensory attributes, were compared .  Go Ferm resulted in the most rapid fermentation.  Not much chemical differences were observed.  Most people preferred the wine made with Fermoplus DAP Free.

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CY3079 and Vivace Yeast Trial in Chardonnay (2015)

Chardonnay wines produced with CY3079 and Vivace yeast strains were compared. Vivace yeast is marketed as a low hydrogen sulfide-producing yeast.  There were little chemical differences between the resulting wines, although significant sensory differences were discerned.  People tended to prefer the wine produced with CY3079.  No conclusions can be drawn about the efficacy of Vivace in producing low levels of hydrogen sulfide.

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Sulfur Dioxide Resistant Strains of EC 1118 (2014)

EC 1118 produces high concentrations of sulfur dioxide during fermentation.  Some sulfur dioxide-resistant strains of EC 1118 have been developed in response to this tendency.  This study examines the difference in wine chemistry, fermentation kinetics, and sensory characteristics of wine produced using traditional EC 1118 and the sulfur dioxide-resistant strain of EC 1118.  The resistant strain produced less volatile acidity, but resulted in a longer fermentation.  No significant sensory differences were found between wines.

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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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Chardonnay Juice Fining with Oenolees (2014)

Chardonnay juice was treated with Oenolees (Laffort) partway during fermentation, and the finished wine was compared to Chardonnay from the same pick that had not had Oenolees addition. Although there was no real chemical difference between the wines, there was a significant sensory difference between wines.  No preference or descriptive data was taken.

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