To evaluate the effect of glycerol in wine, sweetness and viscosity difference thresholds were determined by pair tests using eight trained panelists. In a dry Thompson Seedless wine, the amount of glycerol needed to produce a detectable increase in sweetness was 5.2 g/L. By capillary viscometry, this addition was shown to produce an increase in viscosity of 0.037 milliPascal seconds (mPa s), or 0.037 centipoise (cp). Using a tasteless xanthan gum to increase viscosity with no increase in sweetness, a viscosity difference threshold of 0.141 mPa s (0.141 cp) was found. To produce a corresponding increase in viscosity using glycerol, the addition of 25.8 g/L glycerol is required. Hence, at levels at which glycerol is normally found in wine, from 1.0 to 9.0 g/L, its primary contribution to the sensory properties of wine is to sweetness. Further, in the wine used in this investigation, below a concentration of 25.8 g/L, glycerol does not produce a detectable increase in perceived viscosity.
- Copyright 1984 by the American Society for Enology and Viticulture