Merlot was produced using traditional winemaking practices and sulfur dioxide-free winemaking practices. There were very little chemical differences between the control and low sulfur dioxide treatments. The traditional method seemed to have a higher microbial presence. The traditional method seemed to result in higher phenolic extraction (probably due to increased extraction from sulfur dioxide), but higher color intensity was found in the sulfur dioxide-free wine. This is likely due to less monomeric anthocyanin bleaching. There was no significant sensory difference (p<0.05) between the traditional and sulfur dioxide-free wine. However, of those that responded correctly (n=13) 69% preferred the control and 31% preferred the trial.
Chardonnay was fermented using traditional winemaking and sulfur dioxide-free winemaking. The wine produced had no chemical or microbial differences. Sensory differences were distinguished between the wines, and in general the traditional method was preferred.
Viognier was fermented using traditional winemaking and sulfur dioxide-free winemaking at the pressing stage. Sulfur dioxide was used after the completion of alcoholic fermentation. The wine produced had very little chemical differences, except that the sulfur dioxide-free wine had much more malic acid. The traditional wine in general had a slightly higher microbial presence. Although sensory differences were distinguished between the wines, there was no sensory preferences between the wines.
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.