Tujuan penelitian ini untuk mengetahui viabilitas L.casei dalam yogurt susu kambing dan karakteristiknya selama penyimpanan beku. Yogurt dibuat menggunakan starter probiotik L.casei, disimpan dalam freezer selama 0,2,4,6 hari, dan dievaluasi pH, total asam, dan total probiotik. Hasil penelitian menunjukkan bahwa terjadi penurunan total probiotik   secara signifikan pada penyimpanan hari ke-2, yang ditandai dengan penurunan total asam, total probiotik, dan   peningkatan pH. Diduga terjadi fenomena adaptasi probiotik terhadap kondisi penyimpanan beku setelah hari ke-2 penyimpanan, yang ditandai dengan peningkatan total probiotik, total asam, dan penurunan pH.The aim of this research was to study the viability of L.casei in yoghurt from goat s milk and its characteristic during frozen storage. Yogurts were made with L.casei as a probiotic starter, stored in freezer for 0,2,4,6 days, and evaluated for for pH, titratable acidity, and probiotic count. The results showed that probiotic growth is decreased just on the 2nd day of storage significantly, and it was marked with the decreasing of acidity, probiotic count and the increasing of pH.   The probiotic seemed to be adaptive with the freezing condition after the 2nd day of storage until the 6th day of storage. It was marked with the increasing of probiotic count, acidity, and the decreasing of pH.