The Contribution of Glycerol to Perceived Viscosity and Sweetness in White Wine

Abstract

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.