Three commercial yeast strains were used in the experiments, they are yeast strain from local market,
commercial yeast strain widely known as fermipan, and yeast strain from Madukismo sugar factory in
Yogyakarta; labeled A, B, and C respectively. Yeast strain A was in fine granule form, yeast strain B was
in 1.5 cm flat round brittle dry yeast, while yeast C was culture stock maintained on YPG agar medium.