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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