TOTAL MICROBIAL and pH EFALUATION OF FERMENTED MILK USING Lactobacillus acidophilus STARTER DURING INCUBATION BY TIURMASARI HRP ABSTRACT A study has been conducted to determine the total microbial and pH evaluation of fermented milk of during incubation period. This research was conducted at the Laboratory of milk Technology Faculty of Agriculture Syiah Kuala University from 16 June to 20 June 2014. The growth of Lactobacillus acidophilus was observed in one hour periode as long as 5 hoursincubation periode. The treatmens consist of three level of La persentage, 2%, 4%, and 6%, parameters weasured were total cell acid pH of fermented milk. The results of this study showed the addition of 2% La starter with a 4 hour incubation, bacteria La has grown up to 9.10 cfu with a pH of 4.47. The addition of starter Lactobacillus acidophilus 4% and 3 hour incubation bacteria has grown up to 11.20 cfu with a pH of 4.27, mean while the addition of 6% with 2 hour incubation time has grown up to of 10.67 cfu, with pH 4.24. Total percentage of the added starter able to shorten incubation period. Keywords: total microbial, pH value, lactobacillus acidophilus, daring incubation.