KINETICS OF ALCOHOLIC FERMENTATION UNDER ANISOTHERMAL ENOLOGICAL CONDITIONS .1. INFLUENCE OF TEMPERATURE EVOLUTION ON THE INSTANTANEOUS RATE OF FERMENTATION

In order to describe kinetic differences between isothermal and anisot hermal fermentations, a study using an automatic device for monitoring fermentation was conducted. Isothermal alcoholic fermentations were c ompared with anisothermal fermentations reaching the same final temper ature. In most cases, the rate at the end of the fermentation was fast er under anisothermal conditions. This phenomenon appeared to be influ enced by several parameters, particularly the assimilable nitrogen con tent of the must. However, in some cases, the fermentation rate decrea sed dramatically after the activation was noticed because of the adver se effect of loss of cell viability. Some practical consequences of th ese observations are discussed.