Tujuan penelitian ini adalah menganalisis pengaruh penambahan skim pada bibit kefir lokasi berbeda terhadap nilai pH dan total bakteri asam laktat. Materi yang digunakan adalah 10 L susu sapi segar hasil pemerahan pagi dan bibit kefir sebanyak 3% dari lokasi berbeda. Bahan yang digunakan meliputi MRS agar, skim cair, kapas, kertas sampul coklat, alkohol 90%, micro tip, aquadest, dan buffer pH 4 serta pH 7. Peralatan yang digunakan antara lain tabung reaksi, erlenmeyer 500 ml, gelas jar, pH meter, inkubator, colony counter, autoclave, timbangan digital, alat pengaduk, micropipet, cawan petri, bunsen, beaker glass, gelas ukur, dan botol semprot. Metode penelitian menggunakan Rancangan Acak Lengkap (RAL) Pola Faktorial dengan dua faktor: A (bibit kefir) yaitu A1 = Jawa Timur (Malang), A2 = Jawa Tengah (Banyumas), dan A3 = Jawa Barat (Tasikmalaya); serta faktor B (penambahan skim) yaitu B0 = 0%, B1 = 6%, dan B2 = 8%, masing-masing dengan tiga ulangan. Variabel yang diamati adalah nilai pH dan total bakteri asam laktat (BAL). Data dianalisis menggunakan ANOVA dan dilanjutkan uji BNT jika berpengaruh nyata. Hasil penelitian menunjukkan bahwa faktor A berpengaruh sangat nyata (P<0,01) terhadap pH kefir dengan nilai rata-rata A1 (3,91a), A2 (3,95a), dan A3 (4,02b). Faktor B berpengaruh nyata (P<0,05) dengan rata-rata B1 (3,93b), B0 (3,97a), dan B2 (3,98a). Interaksi AB juga berpengaruh nyata (P<0,05) terhadap pH dengan nilai A1B0 (3,87a), A1B1 (3,91b), A2B1 (3,91b), A1B2 (3,94c), A2B2 (3,95c), A3B1 (3,97d), A2B0 (3,98d), A3B2 (4,03e), dan A3B0 (4,06f). Berdasarkan ANOVA, tidak terdapat pengaruh nyata (P>0,05) terhadap total BAL dengan nilai A3B2 (1,3 × 1010 CFU/ml), A3B0 (1,3 × 1010 CFU/ml), A2B2 (1,8 × 1010 CFU/ml), A2B0 (1,9 × 1010 CFU/ml), A2B1 (2,1 × 1010 CFU/ml), A1B2 (2,6 × 1010 CFU/ml), A1B0 (2,6 × 1010 CFU/ml), A3B1 (4,1 × 1010 CFU/ml), dan A1B1 (4,3 × 1010 CFU/ml). Kesimpulan penelitian menunjukkan bahwa penambahan skim pada bibit kefir lokasi berbeda mempengaruhi nilai pH tetapi tidak mempengaruhi total BAL. Bibit kefir asal Malang dengan skim 6% menghasilkan pH 3,91 dan total BAL 4,3×1010 CFU/ml. Disarankan penggunaan bibit kefir Malang dengan skim 6%, serta penelitian lanjutan pada uji organoleptik, viskositas, dan kadar protein. Kata Kunci : Kefir, Bibit kefir, Lokasi berbeda, Skim, pH, Total BAL. THE EFFECT OF ADDING SKIM ON KEFIR SEEDLINGS IN DIFFERENT LOCATIONS ON THE pH VALUE AND TOTAL LACTIC ACID BACTERIA AbstractThe purpose of this study is to analyse the effect of adding skim on kefir seeds in different locations on the pH value and total lactic acid bacteria. The ingredients used are 10 L of fresh cow's milk from morning milking and 3% kefir seeds from different locations. The ingredients used include MRS agar, liquid skim, cotton, brown envelope paper, 90% alcohol, micro tip, aquadest, and pH 4 and pH 7 buffers. The equipment used include test tube, 500 ml erlenmeyer, glass jar, pH metre, incubator, colony counter, autoclave, digital scale, mixing tool, micropipette, petri dish, bunsen, glass beaker, measuring cup, and spray bottle. The research method uses Complete Randomisation Design (RAL) Factorial Pattern with two factors: A (kefir seed) namely A1 = East Java (Malang), A2 = Central Java (Banyumas), and A3 = West Java (Tasikmalaya); and factor B (skim addition) namely B0 = 0%, B1 = 6%, and B2 = 8%, each with three repetitions. The observed variables are the pH value and the total of lactic acid bacteria (BAL). The data was analysed using ANOVA and continued with the BNT test if it had a real effect. The research results show that factor A has a very significant effect (P<0,01) on the pH of kefir with an average value of A1 (3,91a), A2 (3,95a), dan A3 (4,02b). Faktor B berpengaruh nyata (P<0,05) dengan rata-rata B1 (3,93b), B0 (3,97a), dan B2 (3,98a). Interaksi AB juga berpengaruh nyata (P<0,05) terhadap pH dengan nilai A1B0 (3,87a), A1B1 (3,91b), A2B1 (3,91b), A1B2 (3,94c), A2B2 (3,95c), A3B1 (3,97d), A2B0 (3,98d), A3B2 (4,03e), dan A3B0 (4,06f). Based on ANOVA, there is no real effect (P>0,05) on the total BAL with values of A3B2 (1,3 × 1010 CFU/ml), A3B0 (1,3 × 1010 CFU/ml), A2B2 (1,8 × 1010 CFU/ml), A2B0 (1,9 × 1010 CFU/ml), A2B1 (2,1 × 1010 CFU/ml), A1B2 (2,6 × 1010 CFU/ml), A1B0 (2,6 × 1010 CFU/ml), A3B1 (4,1 × 1010 CFU/ml), dan A1B1 (4,3 × 1010 CFU/ml). The conclusion of the study shows that the addition of skim on kefir seeds in different locations affects the pH value but does not affect the total BAL. Kefir seeds from Malang with 6% skim produce pH 3,91 and total BAL 4,3×1010 CFU/ml. It is recommended to use Malang kefir seeds with a 6% skim, as well as further research on organoleptic tests, viscosity, and protein levels. Keywords : Kefir, Kefir Seeds, Different Locations, Skim, pH, Total BAL.