EFFECT OF VARIETY, YEAR, AND GRAPE MATURITY ON THE KINETICS OF ALCOHOLIC FERMENTATION

The effect of variety, year, and grape maturity on fermentation kineti cs was studied. The differences were quantified by comparing the value s of the maximum CO2 production rates ((dCO(2)/dt)(max)) and the trend s of the (dCO(2)/dt) curves at the end of fermentation. Fermentation k inetics were very different among grape varieties, but also changed si gnificantly with year and maturity. Year above all influenced the maxi mum CO2 production rate (dCO(2)/dt)(max)) when maturity dramatically c hanged the kinetics at the end of fermentation. Kinetic variations wer e also related to must composition changes. The maximum CO2 production rate was correlated to the must assimilable nitrogen concentration wh ile the trend of the dCO(2)/dt curve at the end of fermentation (expre ssed as DM80) was above all a function of the sugar concentration.