Dear student, There is a serious effect of temperature on the rate of fermentation in yeast. The rate should increase from 10°C to 40°C. At 50°C and above, the rates will decrease. The temperature yielding the highest rate of fermentation should be in the 40°C range. The fermentation rate at high temperatures will be low because high temperatures are lethal to yeast. Enzymes move too fast and denature at high temperatures and thus results may vary. Regards