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September 2016 WINES&VINES 59 PRACTICAL WINERY & VINEYARD WINEMAKING SENSORY ATTRIBUTES OF 2011 MERLOT HARVEST Sensory attributes assessed by a trained panel (n=11) of Merlot wines from the 2011 harvest. Evaluations used a 10-point line scale. ( * ) Indicates significant differences for Fisher's LSD and p < 0.05. Color saturation (*) Alcohol (*) Fresh vegetable (*) Earthy (*) Red berry Fruit (*) Dark fruit Chocolate (*) Astringency 5 4 3 2 1 0 Early Harvest Late Harvest Color saturation (*) Alcohol (*) Fresh vegetable (*) Fruit (*) Dark fruit Chocolate (*) Astringency 4 3 2 1 0 Control Extended maceration Color saturation (*) Alcohol (*) Fresh vegetable (*) Earthy (*) Red berry Fruit (*) Dark fruit Chocolate (*) Sweet taste (*) Sweet taste (*) Sweet taste (*) Sweet taste (*) Sour taste (*) Sour taste (*) Sour taste (*) Sour taste (*) Bitter taste (*) Bitter taste (*) Bitter taste (*) Bitter taste (*) Hot mouthfeel (*) Hot mouthfeel (*) Hot mouthfeel (*) Hot mouthfeel (*) Astringency Viscous mouthfeel (*) Viscous mouthfeel (*) Viscous mouthfeel (*) Viscous mouthfeel (*) 5 4 3 2 1 0 Chaptalized Non-chaptalized Earthy (*) Red berry Cooked vegetable (*) Sensory results arising from variations in Brix levels at harvest were of greater magni- tude than that caused by extended maceration. In other words, between 20.5 o and 24.5 o Brix, when grapes are harvested seems to be more influential than the technique chosen to con- duct red wine maceration. In spite of EtOH playing a lesser role in tannin extraction, our results suggest that this solvent is critical to other wine sensory aspects not related to wine tannin content. Unripe fruit gave rise to wines that had lower color satura- tion, a marked vegetal character, higher acidity and lighter body. However, chaptalization of unripe fruit (and the resulting ethanol from it) improved the sensory profile of the resulting wines by increasing the perception of astringency and wine viscosity and reduction of vegetal aro- mas, thereby validating this practice. Previ- ous research has shown that ethanol between 10% and 12% and 14.5% to 17.2% (v/v) affects aroma solubility (and, conversely aroma volatility) in different ways, with some aromas declining and others increasing their volatility as EtOH was increased. For example, it has been previously shown that an increase in EtOH from 14.5% to 17.2% decreased fruitiness. 11 This decrease in fruiti- ness under increasing EtOH levels has been confirmed in model wine solutions 20 and has been ascribed to the ability of EtOH to form "hydrophobic pockets" that may enhance the solubility (thereby decreasing volatility) of certain hydrophobic aromas. Our study under actual winemaking condi- tions suggests that increasing the EtOH level due to chaptalization of unripe fruit has a moderating effect on negative wine aromas and flavors associated with unripe fruit. This may be the result of complex perceptual inter- actions such as synergistic or masking effects between odorant compounds responsible for the aroma and flavor, which were mediated by the ethanol concentration. 20 Although chaptalization is not allowed in California and is allowed only during certain years in Washington state, the practice is more common in states such as Florida, New York and Oregon. If our findings in Merlot hold valid for varieties such as Pinot Noir, which is typically harvested earlier than Merlot, chap- talization of unripe fruit in unseasonably cool years may be beneficial. Color saturation (*) Alcohol (*) Fresh vegetable (*) Earthy (*) Red berry Dark fruit Chocolate (*) Astringency 5 4 3 2 1 0 Low ethanol High ethanol