Impact of Fining on Chemical and Sensory Properties of Washington State Chardonnay and Gewürztraminer Wines

Abstract

The impact of fining on the sensory and chemical properties of Washington State white wine was investigated. Unfined, commercially prepared Chardonnay and Gewürztraminer wines were treated with bentonite (1000 mg/L), isinglass (60 mg/L), Sparkalloid (360 mg/L), activated charcoal (450 mg/L), whole milk (500 mg/L), or wheat gluten (400 mg/L). Ethyl dodecanoate was the only volatile compound to significantly differ among Chardonnay treatments, which was highest in the control (0.031 mg/L) and lowest in Chardonnay treated with bentonite (0.017 mg/L). Conversely, a number of volatile compounds varied significantly among Gewürztraminer treatments. Ethyl acetate was significantly highest in the activated charcoal treatment (25.4 mg/L), while lowest in the Sparkalloid treatment (22.1 mg/L). In addition, Gewürztraminer treated with activated charcoal contained high concentrations of higher alcohols. Wheat gluten significantly decreased the concentrations of 1-hexanol, 3-methyl-1-butanol acetate, and 2-methyl-1-butanol. Benzeneethanol was significantly lower in the Sparkalloid, wheat gluten, and bentonite treatments. Conversely, benzeneethanol was highest in the isinglass (85.2 mg/L) and activated charcoal (74.7 mg/L) treatments. 2-Phenylethyl acetate and linalool were lowest in Gewürztraminer fined with bentonite. No significant differences were found among treatments for either varietal when the wines were subjected to difference testing (duo-trio) by an untrained panel (p ≥ 0.05). No differences were found among Gewürztraminer treatments evaluated by a trained panel, whereas differences in spicy aroma and floral/honey flavor were observed among Chardonnay treatments (p ≤ 0.05). This study demonstrated the impact fining can have on the chemical and sensory properties of wine and confirmed the importance of selecting the appropriate type of fining agent in order to maintain wine quality.