The transition rate kinetics from ethanol oxidation to glucose utilisation, within a structured model of baker’s yeast, described previously, were experimentally identified. The shift in metabolism has been assessed through glucose pulses during batch growth on ethanol. The influence of glucose concentration (between 0.25 gl(-1) and 0.90 gl(-1)) and initial biomass concentration (between 0.61 gl(-1) and 1.44 gl(-1)) on the transition rate was determined. The transition rate can not be described by a first-order saturation-type kinetics with respect to glucose only. A corrective term, which takes into account biomass concentration should be included.