The amount of initial yeast is an important factor which affects the fast or slow development of guava juice fermentation. After the guava had been ground, it was filtered to get guava juice diluted with 35 percent concentration. Guava juice was added sugar to increase the concentration up 18°Bx and supplemented Saccharomyces cerevisiae yeast (STH) with initial yeast concentration from 0.005 percent to 0.03 percent, it was fermented at 30°C temperature within 5 days. The resear.ch results showed that the initial concentration of supplemented yeast at 0.005 percent is the lowest, however amount of producible alcohol met requirements of fermentation products with low alcohol content, assessment sensory quality of products including color, smell and taste is the best.