Abstract
Yeast is a kind of microbes that people always use for daily life benefits. But the most common problems for all the yeast users is the limited storage times and it’s very wasteful to throw away the expired yeast and buy the new one continuously. The purpose of this research was to find the conditions that can best prolong yeast life. By setting up the experiments for two sets that are temperatures and light colors and use Saccharomyces cerevisiae in this experiment. In the first experiment, raise the yeast in the three different temperature that are 2 Celsius with 28% humidity, 20 Celsius with 70% humidity and 40 Celsius with 55% humidity. The result shows that 25 Celsius is the temperature with the most yeast left in it and cell’s most average density is 118,083,333.33 cell/ml. The results are different in the same 0.05 significance level. And in another experiment, raise the yeast in three different light colors that are red, blue and white. The result shows that red is the color with the most yeast left in it and cell’s most average density is 115,333,333.33 cell/ml. The results are different in the same 0.05 significance level.