Soyghurt atau yoghurt berbasis kacang kedelai adalah produk pangan probiotik dari hasil fermentasi susu yang melibatkan bakteri asam laktat (BAL) Lactobacillus bulgaricus dan Streptococcus thermophilus. Penambahan Lactobacillus acidophilus, Lactobacillus plantarum, dan Lactobacillus casei dapat meningkatkan kemampuan probiotik dari soyghurt. Penggunaan sari kulit nanas dan stabilizer seperti CMC (Carboxy Methyl Cellulose) dapat meningkatkan kualitas mutu soyghurt. Penelitian ini bertujuan untuk mengetahui pengaruh konsentrasi starter dan CMC serta penambahan sari kulit nanas terhadap mutu soyghurt. Penelitian diawali dengan pembuatan soyghurt menggunakan kombinasi konsentrasi starter (0.05%; 0.1%; 0.15%; 0.2%) dan CMC (0.2%; 0.4%; 0.6%). Kombinasi konsentrasi starter dan CMC terpilih memiliki hasil nilai pH 4.33 ± 0.01, total asam tertitrasi 0.50 ± 0.03 %, total BAL 6.48 ± 0.02 log CFU/mL, total mikroba 7.99 ± 0.00 log CFU/mL, total padatan terlarut 6.25 ± 0.35 °Brix, dan nilai viskositas 89.75 ± 0.03 cP. Soyghurt dengan kombinasi konsentrasi starter dan CMC terpilih dilakukan penambahan sari kulit nanas dengan konsentrasi 5%; 10%; 15%; 20%. Soyghurt dengan sari kulit nanas terpilih menghasilkan nilai pH 4.36 ± 0.01, total asam tertitrasi 0.44 ± 0.03 %, kandungan vitamin C 0.0310 ± 0.00 mg/mL, total BAL 6.47 ± 0.09 log CFU/mL, total mikroba 7.69 ± 0.01 log CFU/mL, total padatan terlarut 6.67 ± 0.58 °Brix, nilai viskositas 27.67 ± 0.00 cP, lebih disukai panelis dibandingkan soyghurt dengan konsentrasi sari kulit nanas lainnya, dan ketahanan asam 5.76 ± 0.04 CFU/mL / Soyghurt or soybean-based yogurt is a probiotic food product from fermented milk containing lactic acid bacteria (LAB) Lactobacillus bulgaricus and Streptococcus thermophilus. The addition of Lactobacillus acidophilus, Lactobacillus plantarum, and Lactobacillus casei can increase the probiotic ability of soyghurt. The use of pineapple peel extract and stabilizers such as CMC (Carboxy Methyl Cellulose) can improve the quality of soyghurt. This study aims to determine the effect of starter concentration and CMC and the addition of pineapple peel extract on the quality of soyghurt. The study began with making soyghurt using a combination of starter concentrations (0.05%; 0.1%; 0.15%; 0.2%) and CMC (0.2%; 0.4%; 0.6%). The combination of the selected starter and CMC concentrations resulted in a pH value of 4.33 ± 0.01, total titrated acid 0.50 ± 0.03%, total LAB 6.48 ± 0.02 log CFU/mL, total microbes 7.99 ± 0, 00 log CFU/mL, total dissolved solids 6.25 ± 0.35 °Brix, and viscosity value 89.75 ± 0.03 cP. Soyghurt with a combination of starter concentration and selected CMC was added with pineapple peel extract with a concentration of 5%; 10%; 15%; 20%. Soyghurt with selected pineapple peel extract produced a pH value of 4.36 ± 0.01, total titrated acid 0.44 ± 0.03%, vitamin C content 0.0310 ± 0.00 mg/mL, total BAL 6.47 ± 0 .09 log CFU/mL, total microbial 7.69 ± 0.01 log CFU/mL, total dissolved solids 6.67 ± 0.58 °Brix, viscosity value 27.67 ± 0.00 cP, preferred by panelists over soyghurt with other pineapple peel extract concentrations, and acid resistance 5.76 ± 0.04 CFU/mL.