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Fifty-one Canadian ice wines, representative of a range of varieties and vintages, were evaluated chemically and 20 wines further evaluated sensorally. Ice wines from British Columbia and Ontario were significantly different for a range of chemical and sensory attributes. British Columbia ice wines had higher titratable acidity, acetic acid and glucose, and lower colour and ethyl acetate content compared with those from Ontario. Apricot, raisin, honey and oak aromas were more pronounced in Ontario ice wines, while British Columbia ice wines had higher intensities of pineapple and oxidized aromas. Riesling ice wines had higher titratable acidity and glucose and lower pH and A 420 values compared with Vidal. Vintage effects were also found for pH, A 420 , glucose, fructose, ethanol and ethyl acetate.

The contribution of glycerol, ethanol and sugar to the perception of viscosity and density of model wine (MW) solutions was examined. In study 1, the effects of individual components on perceived viscosity (PV) and perceived density (PD) were studied using 5, 20 or 50 g/L glycerol; 3, 7 or 15% v/v ethanol and 0, 80, 150 or 250 g/L sugar concentrations. In study 2, model ice wine mixtures of 8, 10 or 12% ethanol and 150, 250 or 300 g/L sugar were assessed for PV and PD. The physical viscosity and density of the MWs were also measured in both studies. Across the range of concentrations investigated, sugar influences the perception of viscosity and density the most, ethanol has a moderate effect and the contribution of glycerol is nominal. In model ice wine solutions, PV and PD increased with sugar concentration, but were minimally affected by changes in ethanol concentration. The PV elicited by the model ice wine solutions was well described by a linear model using physical viscosity as the independent variable (r: 0.907). This information may be useful for predicting the sensory properties of the ice wine for quality control purposes.

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The effect of inoculation with selected Saccharomyces cerevisiae strains was studied on fermentation and flavor compounds of wines made from Vitis vinifera L. cv. Emir grown in Central Anatolia, Turkey. Flavor compounds were analysed and identified by GC-FID and GC-MS, respectively. The total concentrations of flavor compounds did not increase with the addition of indigenous and commercial wine yeasts, but differences were noted in individual volatile compounds. Cluster and factor analyses of flavor compounds also showed that wines produced were different depending on the wine strain used. Wines were completely fermented to less than 1.4 g/l residual sugar. Yeasts other than S. cerevisiae survived longer than previously reported. Inoculation with selected strains increased the ethanol level.

Interactions between taste and irritant sensations elicited by model ice wine solutions were investigated, including the use of U and Γ′ models for predicting the perceived intensity of these sensory interactions. Fifteen solutions of varying ethanol and sugar concentrations representative of commercial ice wine values were evaluated in two trials by a trained sensory panel (n = 12) for perceived sweetness, bitterness and heat intensities. Sweetness perception of lower sugar‐concentration level in ice wine model solution was affected by ethanol concentration. The sweetness intensities of the sugar and ethanol mixtures are higher than the sweetness intensities of sugar solutions. The Γ′ index indicates a slight synergy between ethanol and sugar on sweetness perception. The bitterness intensities elicited by ethanol–sugar mixtures are lower than those elicited by unmixed ethanol solutions. The Γ′ index indicates inhibition of ethanol and sugar perception on bitterness perception. Suppression of heat sensation was found in model base wine solutions across sugar and ethanol concentrations.

This project aims to characterize and define an autochthonous yeast, Saccharomyces bayanus CN1, for wine production from partially dehydrated grapes. The yeast was identified via PCR and Basic Local Alignment Search Tool (BLAST) analysis as Saccharomyces bayanus, and then subsequently used in fermentations using partially dehydrated or control grapes. Wine grapes were dried to 28.0°Brix from the control grapes at a regular harvest of 23.0°Brix. Both the partially dehydrated and control grapes were then vinified with each of two yeast strains, S. bayanus CN1 and S. cerevisiae EC1118, which is a common yeast used for making wine from partially dehydrated grapes. Chemical analysis gas chromatography-flame ionization detector (GC-FID) and enzymatic) of wines at each starting sugar level showed that CN1 produced comparable ethanol levels to EC1118, while producing higher levels of glycerol, but lower levels of oxidative compounds (acetic acid, ethyl acetate, and acetaldehyde) compared to EC1118. Yeast choice impacted the wine hue; the degree of red pigment coloration and total red pigment concentration differed between yeasts. A sensory triangle test (n = 40) showed that wines made from different starting sugar concentrations and yeast strains both differed significantly. This newly identified S. bayanus strain appears to be well-suited for this style of wine production from partially dehydrated grapes by reducing the oxidative compounds in the wine, with potential commercial application for cool climate wine regions.

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