The Effect of Stabulation on Fermentation Kinetics and Sensory Quality (ARC) (2016)

This study examines the effect of different rosé must processing techniques on the chemical and sensory qualities of finished wine. Merlot grapes were either sent directly to press or cold soaked for two days prior to pressing. After cold soak and pressing, juice was either settled and inoculated or stabulated for approximately 5 days, after which it was inoculated and a Laffort thiolase enzyme was added. Merlot sent directly to press underwent stabulation. Not many chemical differences could be seen between stabulated juices with the control, except a higher initial turbidity. These results suggest that for this particular style of rose winemaking, judges preferred wine made from the two-day cold soak, regardless of stabulation. Although the stabulated and control wines were found to be significantly different, no major trends could be seen for the descriptors used in this study except for perhaps a slight increase in fruit intensity and thiol aromas. No major preference could be seen for the control wine and stabulated wine, suggesting that stabulation can act as a technique to process wine without much altering the flavor profile in a negative matter.

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Color and Tannin Extraction and Stabilization in Red Winemaking (ARC) (2016)

This study examines the impact of different tannin addition practices on the color and tannin profiles of Merlot wine. Merlot was harvested from the same block and split into three separate fermentation vessels. One vessel received no tannin or oak chip additions, a second vessel received VR Supra and Lafase HE Grand Cru at processing, and VR Color during fermentation (ARC-Laffort Protocol), and a third treatment received Lafase HE Grand Cru and mini chips bois frais oak chips at processing. All other treatments between wines were equal. Wine chemistry between treatments were the same, except that the control tended to have slightly lower TA. Both treatments increased color intensity and tannin, with the Laffort-ARC protocol having the greatest impact. The treatments slightly increased catechin and gallic acid. The treatments tended to slightly lower anthocyanins, but increased polymeric pigment. No strong trends could be seen for the descriptors used in this study. There was a slight tendency for the control to have higher Fruit Intensity and lower Astringency. The Oak Chips + Grand Cru had a slight tendency to increase Body, Bitterness, and Overall Aromatic Intensity. However, these were weak trends. In general, the ARC-Laffort Protocol Treatment was the least preferred. Several judges described these wines as having slightly oxidized characteristics, and as such these sensory results may not be very representative. 

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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 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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